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Honoring Earth and Space Scientists

Wed, 04/18/2018 - 12:37

The Cassini mission team will receive the 2018 John L. “Jack” Swigert, Jr., Award for Space Exploration from the Space Foundation. The foundation presents the Swigert Award annually for a significant advancement of space exploration during the previous year. The Cassini mission, which ended in September 2017, was recognized for its more than 20 years of work revolutionizing our understanding of Saturn, its rings and moons, and how planetary systems form. The team of the Cassini mission, which was a joint mission of NASA, the European Space Agency, and the Italian Space Agency, will receive this award on 16 April during the opening ceremony of the 34th Space Symposium in Colorado Springs, Colo.

Northwestern University announced, on 13 April, the winners of the 2018 Nemmers Prizes. Among them, receiving the first Nemmers Prize to be awarded in Earth sciences, is Francis Albarède, who is recognized for “his fundamental applications of geochemistry to earth sciences.” Albarède is an emeritus professor of Geochemistry at École Normale Supérieure de Lyon in France; an adjunct faculty at Rice University in Houston, Texas; and a world leader in using geochemistry to understand the history of Earth and the solar system. He has contributed to knowledge of high-temperature geodynamic processes, planetary sciences, and marine geochemistry, according to a prize announcement. The honor includes a cash award of $200,000.

Jim Green, who is currently the director of NASA’s Planetary Science Division, will step into his new role as NASA chief scientist on 1 May. Green was appointed to this new position on 10 April by acting NASA administrator Robert Lightfoot. Green has served as director of the Planetary Science Division, part of NASA’s Science Mission Directorate, since 2006, overseeing key missions to many solar system destinations and setting the groundwork for future NASA missions to Mars and Europa. After Green begins as chief scientist, Lori Glaze will serve as acting director of the Planetary Science Division. Glaze is currently the chief of the Planetary Geology, Geophysics, and Geochemistry Laboratory at Goddard Space Flight Center in Greenbelt, Md.

On 5 April, France Cordóva, director of the National Science Foundation, was inducted into the U.S. News and World Report’s STEM Leadership Hall of Fame. Córdova is an astrophysicist who focused her research on high-energy cosmic phenomena and instrumentation. Córdova is president emerita of Purdue University; is chancellor emerita of the University of California, Riverside; was NASA’s chief scientist from 1993 to 1996, the youngest person and first woman to hold that position; is a fellow of the American Association for the Advancement of Science and of the Association for Women in Science; is a Kilby Laureate and a recipient of the NASA Distinguished Service Medal; was chair of the Smithsonian Institution Board of Regents from 2012 to 2014; and is a past member of the National Science Board. Córdova and three other honorees were inducted into the hall of fame at an awards luncheon at the U.S. News STEM Solutions Presents Workforce of Tomorrow conference in Washington, D. C.

Ellen Stofan was named the head of the National Air and Space Museum on 5 April. Stofan will come to the position from her current role as a consulting senior scientist at the Johns Hopkins Applied Physics Laboratory. A leader in the planetary science community for decades, Stofan served as NASA chief scientist from 2013 to 2016, has addressed the World Economic Forum’s Council on the Future of Space Technologies at Davos, has conducted research in planetary sciences in the United States and internationally, and coauthored two National Geographic books about the future of planetary science. Stofan will begin her tenure at the museum, located in Washington, D. C., on 30 April.

Five early-career astronomers were named 2018 Sagan Fellows as part of the NASA Hubble Fellowship Program (NHFP) on 3 April. The Sagan Postdoctoral Fellowship, named in honor of the late Carl Sagan, is one of three prestigious fellowships within NHFP and is awarded to outstanding early-career researchers who focus on extrasolar planets and the origin of life. Ian Czekala will research the birth of stars and their young planetary systems at the University of California, Berkeley. Johan Mazoyer will investigate the possibility of detecting exo-Earths with large space-based coronagraph instruments at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Erik Petigura will research the origin of small planets at the California Institute of Technology in Pasadena. Kamber Schwarz will study the evolution of volatile molecules in protoplanetary disks and exoplanet atmospheres at the University of Arizona in Tucson. Daniel Tamayo will research the dynamical evolution of exoplanet systems and how to characterize such systems at Princeton University in Princeton, N. J. The Sagan Fellows will begin their research at their chosen institutions in the fall of 2018.

Kenneth Graham began his appointment as the director of the National Oceanic and Atmospheric Administration (NOAA) National Hurricane Center in Miami, Fla., on 1 April. Graham has worked with NOAA for many years as a leading meteorologist at National Weather Service (NWS) offices around the United States. In his positions within NOAA and NWS, Graham aided Hurricane Katrina recovery efforts in Forth Worth, Texas; advised response teams after the 2011 Deepwater Horizon oil spill; and worked with Mississippi and Louisiana decision makers to predict and mitigate impacts of recent hurricanes along the Gulf Coast. Graham took over the position from Ed Rappaport, who returned to his position as the center’s deputy director after serving as acting director since May 2017.

Joan Schmelz was elected vice president of the American Astronomical Society (AAS) on 20 February. Schmelz is currently the program director for the Universities Space Research Association and has a long history of leadership in the astronomical community. In addition to her research in solar and stellar astronomy and many other accomplishments, Schmelz is the deputy director of Arecibo Observatory, was a program officer of the National Science Foundation, and was chair of the AAS Committee on the Status of Women in Astronomy. In her new position, she plans to continue her advocacy efforts for gender diversity and will be a key player in preparing the Astro 2020 decadal survey. Schmelz will serve in the office for 3 years starting in June.

The Solar Physics Division of the AAS named Sarbani Basu and Nicholeen Viall as recipients of two of their annual prizes. Basu will receive the 2018 George Ellery Hale Prize, which is awarded for outstanding long-term contributions to solar astronomy, for her decades of work understanding quakes, oscillations, and “ringing” in the Sun and in distant stars. Basu is a professor and chair of the Department of Astronomy at Yale University in New Haven, Conn., and will continue her stellar ringing work with data from various NASA satellites. Viall, an astrophysicist at NASA Goddard Space Flight Center in Greenbelt, Md., was chosen as the 2018 Karen Harvey Prize recipient for her work on understanding the solar corona, the solar wind, and near-Earth space weather. The Karen Harvey Prize recognizes outstanding contributions to the field by early-career scientists. Basu and Viall will each receive their award and deliver a prize lecture during the Triennial Earth-Sun Summit in Leesburg, Va., in late May.

The post Honoring Earth and Space Scientists appeared first on Eos.

Snapshots of March for Science Signs Across the Globe

Wed, 04/18/2018 - 12:36

For the second year in a row, people across the United States and on all seven continents held rallies in support of science. Speakers and marchers at more than 230 events around the world advocated for increasing diversity in science, defending science from funding cuts and government interference, and promoting science literacy and trust.

Saturday’s March for Science events may have drawn smaller crowds than last year, but the participants were as enthusiastic as ever about the advancement of science. Here are some of our favorite posters that captured the spirit of these marches.

At the D. C. March

Some protested policies that put industry profits over environmental protection.

The first signs we encountered heading to @marchforsciencedc. pic.twitter.com/PUMoBmjJD1

— Footprint Network (@EndOvershoot) April 14, 2018

Other demonstrators warned that ignoring scientists could have disastrous consequences.

May the second #MarchForScience tomorrow be a tipping point toward returning science to policy decisions. (picture via @MarchForScience) pic.twitter.com/VhTaJEcMv3

— Laurel Standley (@Laurel_Standley) April 14, 2018

Is scientific consensus a conspiracy? Ridiculous!

"Get real. Scientist do not conspire. We can't even agree on authorship order," reads a sign from Julie #marchforscience2018 pic.twitter.com/2xS7LoRb6W

— Zahra Hirji (@Zhirji28) April 14, 2018

Something to hang your hat on.

Credit: Peter Weiss

One D. C. participant showed her support for science with a classic chemistry pun.

Loved all of the energy at @ScienceMarchDC. Let’s keep the momentum going! #ScienceNotSilence pic.twitter.com/PCJ6FdqABK

— Samantha Swamy (@SamanthaSwamy) April 14, 2018

Science education matters, too.

Science teachers rule! At the @ScienceMarchDC pic.twitter.com/ZzzCTNYHSn

— Carolyn Foote (@technolibrary) April 14, 2018

Two protesters, one taking a pause from identifying proteins.

"Science be curious" and "I could be running a western blot but I'm here" are 2 more signs at the #marchforscience. Two women with the group @sacnas marching pic.twitter.com/nb9BoiWHp4

— Zahra Hirji (@Zhirji28) April 14, 2018

In Cities Across the United States

Large or small, almost every U.S. state and territory hosted a March for Science demonstration.

A graduate student at the University of California in San Francisco with another chemistry pun.

Siyu Feng, a PhD student in biology at UCSF, is one of many participants at San Francisco's #MarchforScience today. pic.twitter.com/82RPkfejXU

— WIRED Science (@WIREDScience) April 14, 2018

Marchers in New York City, this time with a math pun.

Happened to stumble across the #marchforscience2018 today. Loved this sign. pic.twitter.com/90ZgVMxkdx

— Jonathan Larkin (@jonathanrlarkin) April 14, 2018

Signs from Philadelphia, Pa.

So excited to have @PSUBrandywine students supporting science at @PHLScienceAct #RallyforScience! #STEMstudents #MarchForScience #Philly pic.twitter.com/iGGnw9e1ao

— Dr. G (@guertin) April 14, 2018

In Los Angeles, Calif., a protester brings on the biology.

It’s @march4sciencela time y’all! #MarchForScience #MarchForScienceLA pic.twitter.com/GhoVKCBaax

— Jaime Cordova (@jaimecor_94) April 14, 2018

Marchers in San Antonio, Texas, with a touch of magic.

@ScienceMarchSA #MarchforScienceSA18 pic.twitter.com/JIhSZ78J0B

— Mary Anne (@MaremaAnne) April 14, 2018

One protester in Colorado, calling out federal science agencies that have been known to censor information.

Baby’s first march in Colorado #MarchForScience2018 #MarchForScience pic.twitter.com/QKTRB5NRhH

— Ali Branscombe (@alibranscombe) April 14, 2018

And in Sacramento, Calif., one demonstrator turned her attention to scientific misconduct on the international stage. Her sign translates to “No to the adjustment of science in Argentina.”

Make Science Great Again ! #marchforscience2018 #Sacramento pic.twitter.com/to0sHqPe8g

— MariaFlorenciaErcoli (@NeCesiTo1TiemP0) April 14, 2018

On Every Continent

The 2018 March for Science remained a global event, with more than 100 worldwide events ranging from high in the Chilean mountains to equatorial Africa to the icy tundra of Antarctica.

In Abuja, Nigeria, scientists and advocates marched to promote public trust in science and to emphasize that scientific advancement benefits the entire population.

You see how cool science is? Nigeria is Marching!!! @ScienceMarchDC #MarchforScience pic.twitter.com/oOt2tR1jx6

— Modesta (@modestannedi) April 14, 2018

Standing up for science — Abuja, Nigeria. @OFABnigeria @Nigerians4GMO #marchforscience2018 pic.twitter.com/xVkpoitCZu

— Alliance for Science (@ScienceAlly) April 14, 2018

Marchers of all ages in Narrandera in New South Wales, Australia, with signs saying “Science, not silence,” “Heads in books, not heads in sand,” and “Science…the spectrum of awesome.”

Narrandera has now been added as an official #MarchForScience location! pic.twitter.com/GIxbFvB2F0

— Fiona Caldarevic (@FionaMagic) April 14, 2018

One marcher in London simultaneously raised awareness of rising sea levels and promoted gender diversity in science.

#MarchForScience pic.twitter.com/686VTrcYq9

— Anieke Brombacher (@jfabrombacher) April 14, 2018

Demonstrators at an event in Vancouver in British Columbia, Canada.

Powered by science and strengthened by diversity! Speaking up for science at the #marchforscience2018 @ScienceMarchYVR today with fellow supporters! pic.twitter.com/egTPOfy7Tb

— The SPIN (@SPINSciPolicy) April 15, 2018

In Quezon City in the Philippines advocates held signs proclaiming “Climate justice” and “March for science, march for the people.” In Blantyre, Malawi, supporters’ signs read “Science not silence” and “Mad scientist.” And in Chennai, India, activists marched with placards urging “Science unites! Stand up for science!” and “Defend science and scientific outlook.”

Happy #MarchforScience day! One of my favorite parts of waking up today is seeing so many photos of communities standing up for science, equity, & justice all around the world. See you in the streets! #KeepMarching

(Pics: Philippines, Malawi, India, Antarctica) pic.twitter.com/xhUQmQDSoa

— Lucky Tran (@luckytran) April 14, 2018

Meanwhile in Antarctica, the team of climate scientists at Neumayer Station III proclaimed, in the translated words of Prussian naturalist Alexander von Humboldt, “Knowledge and recognition are the joy and the right of humanity.”

Message of support from Antarctica: overwinterer at the Neumayer Station support the #MarchForScience @ScienceMarchDC pic.twitter.com/ISrptu1Gfi

— AWI Media (@AWI_Media) April 14, 2018

—Kimberly M. S. Cartier (@AstroKimCartier), Staff Writer

The post Snapshots of March for Science Signs Across the Globe appeared first on Eos.

Scientists Examine Novel Options to Save Coral Reefs

Wed, 04/18/2018 - 12:35

A global bleaching event that devastated many coral reefs around the world from 2014 to 2017 has further raised the sense of urgency among coral experts to protect the reefs from damage from future elevated temperature conditions. The National Oceanic and Atmospheric Administration (NOAA) says the event is the third such global episode and the most widespread, longest, and most damaging bleaching event on record. This latest round of devastation is prompting scientists to examine potentially radical interventions.

A study by an ad hoc committee of the National Academies of Sciences, Engineering, and Medicine, which kicked off in February, is looking into the science, risks, and benefits of a range of possible interventions—some involving engineering, others mainly ecological or genetic—to help reefs recover and survive.

“The major problem that we are faced with is that our conventional methods of coral reef conservation that we have come to rely on are not keeping pace with the environmental change that we are seeing these days,” Ned Cyr, director of the NOAA Fisheries Office of Science and Technology, said on 8 February. He was speaking at the initial meeting of the committee, which is in fact-finding mode in its 2-year study of interventions to increase the resilience of coral reefs. NOAA, the study’s sponsor, has environmental stewardship responsibilities that involve coral science, coral assessment and management, and conservation of corals under the U.S. federal Endangered Species Act, said Cyr, one of several NOAA scientists who made presentations to the committee about the state of reefs and the agency’s goals for the study.

Coral reefs provide ecosystem goods and services such as fisheries, storm surge protection, and tourism. However, under stressful conditions such as higher than normal temperatures, bleaching can occur when corals expel symbiotic algae. This expulsion causes the corals to turn white and become more vulnerable to disease.

“We spend millions [of dollars] on coral reef marine protected areas, on implementing sustainable fishing practices, minimizing land-based sources of pollution, replanting reefs with live corals, etc., and yet these intervention methods simply don’t match the scale of what we are facing now from global warming,” Cyr remarked. Rising levels of atmospheric carbon dioxide are leading to changing pH and calcification conditions in the oceans that are having profound consequences for reefs, he added.

“We really need new solutions that match the scale of the problem.”“We really need new solutions that match the scale of the problem,” Cyr said. “What we really need is a paradigm shift in our approach to conservation biology.”

Radical Interventions

The project scope for the committee’s study states that reefs are threatened by “rapidly deteriorating environmental conditions that are warmer, less favorable for calcification, have impaired water quality, and pose continuing disease threats.” The study calls for looking into strategies that include translocating nonnative coral stocks or species, managed selection, “stress hardening,” and engineering solutions such as shading and cooling reefs during bleaching events. “Although these interventions raise societal, policy, legal, and likely ethical implications for decision making, these considerations are beyond the scope of this review,” the project scope notes.

Some of the interventions “are not without controversy within the scientific community and the conservation community,” Cyr told the committee, mentioning, for instance, potential concerns about genetically modified organisms, or “frankenfish.” “Where you can help us is by helping to develop a consensus for the science and management community to justify the testing and the implementation of some of these novel techniques that we think ultimately are going to be helpful in our conservation mission.”

At the meeting, Jen Koss, director of NOAA’s Coral Reef Conservation Program, told the committee that although “radical solutions” are needed quickly, “we are mindful that these need to be reviewed.” She noted past examples of interventions in other ecosystems that led to significant problems, such as introducing kudzu for soil retention in the southeastern United States.

Committee Concerns

Committee members largely agreed with the scope of the problem and the need to do something quickly about it. “The conventional things that we are doing aren’t really working or certainly aren’t working well enough or fast enough,” committee member Nancy Knowlton told Eos. Knowlton is a coral reef biologist and the Sant Chair for Marine Science at the Smithsonian Institution. She is also a senior scientist emeritus at the Smithsonian Tropical Research Institute.

“We are faced with a situation here even in reefs which have been well managed with respect to, say, overfishing and pollution, which are the things that were problematic, say, a couple of decades ago,” Knowlton continued. Corals “are still being hit really, really hard by, particularly, global warming in these mass bleaching events.”

The committee is looking into potential ecological, genetic, and engineering interventions to help coral reefs. This aerial photo shows coral bleaching in March 2016 in New Caledonia, a French territory in the South Pacific. Credit: The Ocean Agency/XL Catlin Seaview Survey/Richard Vevers

An important consideration is weighing the costs and benefits of potential interventions such as moving species around the world, committee chair Stephen Palumbi told Eos, while bearing in mind those that have sometimes gone awry. Past failures are “a huge wake-up call” about the need to be “very careful” in considering and potentially using new interventions, added Palumbi, a professor of marine biology at Stanford University’s Hopkins Marine Station, Pacific Grove, Calif.

The goal is to have coral reefs “that can persist and thrive and still benefit humans even if we’re causing the climate to change into the future,” he said.

“We know that climate change is accelerating and accelerating bleaching. And so we need to make sure that this study isn’t something that talks about some nice areas of science but is too little and too late for the corals.”Mark Eakin, coordinator of NOAA Coral Reef Watch, emphasized to the committee the need for quick, effective action. “We know that climate change is accelerating and accelerating bleaching,” he said. “So we need to make sure that this study isn’t something that talks about some nice areas of science but is too little and too late for the corals.”

—Randy Showstack (@RandyShowstack), Staff Writer

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Societal Impacts Collection Continues to Grow

Wed, 04/18/2018 - 12:29

To celebrate Earth Day in 2017 and the March for Science held on the same day in locations across the globe, AGU commissioned a collection of Commentaries demonstrating the benefits of Earth and space science research for society.

Galvanized by the momentum of the March(es) for Science, enthusiastic authors wrote articles describing the importance of their science in straight-forward language understandable by the layperson. AGU’s journal editors and publication staff worked within a tight timeframe to review and finalize these pieces, then our publishing partner, Wiley, sped them through the production process for simultaneous release on 20 April 2017.

It was a huge team effort, but the dedication and commitment shown by authors and staff served to reinforce how seriously we took the opportunity to describe how scientific research can contribute to understanding, addressing, and mitigating major challenges facing humankind.

The collection was a great success. The 29 commentaries covered topics ranging from the significance of space weather and the impact of climate change on beaches, to using satellite data to monitor ocean currents, and ways to capture carbon dioxide.

Over the past year, the full text of these articles have been downloaded almost 40,000 times, the most popular being Water and life from snow: A trillion dollar science question, The food-energy-water nexus: Transforming science for society, and Creeping faults: Good news, bad news?

The pieces in the collection boast a combined Altimetric score of 467 (a measure of how many times the articles have been shared via news outlets, blogs, social media and other means), and the individual commentaries have already been cited in the scholarly literature 56 times. These figures speak to the relevance and impact of this collection.

We have decided to make Earth and Space Science is Essential for Society a living collection and will be adding new commentaries over time. To celebrate the 2018 March for Science, we have added 15 more articles, all of which present further evidence of how research in these fields can contribute insights into pressing social, environmental, and economic issues.

Some of the new commentaries explore how land use change effects flooding and the impacts of living near livestock farms on human health, early warning systems for catastrophic fires and monitoring changing conditions in the high Arctic, mining resources on the deep seafloor and communicating climate change risks.

All content in the Earth and Space Science is Essential for Society collection is free to read, download and share.

Jenny Lunn, Director, and Paige Wooden, Senior Program Manager, Publications, American Geophysical Union; email: jlunn@agu.org

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Atmospheric Teleconnections: Advanced Tools and Citizen Science

Tue, 04/17/2018 - 12:02

Often, the physics and dynamics underlying teleconnections are neither well understood nor accurately represented by state-of-the-art climate models.Strong El Niño episodes are characterized by warm sea surface temperatures and strong thunderstorm activity in the eastern tropical Pacific, but their influence is nearly global. Such episodes can induce severe droughts and wildfires in some faraway regions and intense rainfall and catastrophic floods in others. These remote linkages, or drivers, are examples of atmospheric teleconnections, and they play a critical role in regional climate variability.

Often, the physics and dynamics underlying such teleconnections are neither well understood nor accurately represented by state-of-the-art climate models. Overcoming this knowledge gap will be key to improving not only future regional climate change projections but also seasonal forecasts. Improving projections and forecasts would have huge societal benefits, especially in regions that are particularly vulnerable to climate change impacts. To better understand atmospheric teleconnections, the next generation of climate scientists must be holistically trained in the underlying physics, climate modeling, and innovative data analyses techniques.

A visualization of a complex climate network based on global surface air temperature data. Nodes represent the spatial locations of individual temperature time series data, and links indicate strong statistical similarities between nodes. The color of a node shows the number of its connections to other nodes (green for small values and red for large ones), and its size encodes the number of shortest paths connecting nonneighboring nodes passing through it (an attribute called “betweenness” in network theory). From the links shown, it is obvious that the tropics are strongly interconnected, but links to the extratropics can also be prominent. Credit: Thomas Nocke; reproduced from Nocke et al., 2015, https://doi.org/10.5194/npg-22-545-2015, CC BY 3.0

One project, called Globally Observed Teleconnections and Their Role and Representation in Hierarchies of Atmospheric Models (GOTHAM), aims to better understand large-scale modes of climate variability and their mutual interactions. This project is funded by the Belmont Forum and the Joint Programming Initiative “Connecting Climate Knowledge for Europe” (JPI Climate). GOTHAM combines novel complex system-based analysis methods with superensembles of atmospheric models generated through distributed computing using the citizen science platform climateprediction.net (also known as CPDN).

Within the framework of this project, 27 aspiring young scientists and several experts on teleconnection patterns and data science attended the GOTHAM International Summer School in Potsdam, Germany. Similar to GOTHAM itself, the school program integrated diverse topics, including midlatitude flow, stratospheric teleconnections, the El Niño–Southern Oscillation, and monsoons. The program also focused on the interplay between these different teleconnections and the affected regions. (A detailed report of the summer school can be found here.)

In addition to in-depth lectures and student poster sessions, practical exercises provided hands-on training for CPDN and several Python-based complex systems tools. For example, one group of students used CPDN data on the unique atmospheric circulation pattern of summer 2010, which induced severe weather extremes like the heat wave in Russia and floods in Pakistan. Advanced, complex network-based analysis techniques were applied to a large ensemble of simulations of that summer to help understand the underlying physical pathways.

Our experience with this summer school demonstrates that integral training on theory and practice can be achieved within only 1 week.Our experience with this summer school demonstrates that integral training on both theory and practice can be achieved within even the short period of only 1 week. The participating young researchers obtained important foundational training for applying their newly gathered methodological skills to their specific research questions. They also started new collaborations with climate and data experts.

Finally, the school underscored the necessity and importance of combining expertise from different disciplines: climate scientists, data scientists, and seasonal forecast experts. Integrating these different fields constitutes a crucial step toward better understanding the physics behind and the role of atmospheric teleconnections.

The authors thank Scott Osprey and all GOTHAM partners for their support in organizing this school. Financial support has been provided by the German Federal Ministry for Education and Research (grants 01LP1611A and 01LN1306A).

—Eftychia Rousi (email: rousi@pik-potsdam.de), Potsdam Institute for Climate Impact Research, Germany; Dim Coumou, Potsdam Institute for Climate Impact Research,  Germany; also at Institute for Environmental Studies, Vrije Universiteit Amsterdam, Netherlands; and Reik V. Donner, Potsdam Institute for Climate Impact Research, Germany

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Fluid Injection Wells Can Have a Wide Seismic Reach

Tue, 04/17/2018 - 12:02

Seismologists largely attribute widespread earthquakes in southern Kansas and northern Oklahoma over the past several years to injection of extracted oil field brine deep into Earth’s crust. Recently, however, the frequency of earthquakes has increased significantly in areas of Kansas well beyond the initial high-seismicity zones near injection wells.

Kansas has a unique vantage point for observing far-field effects of injection.Because the vast majority of high-volume injection wells in the region are near and south of its border with Oklahoma, Kansas has a unique vantage point for observing far-field effects of injection.

Recent measurements show that subsurface fluid pressures are elevated across south central Kansas, including areas where injection practices have been relatively consistent for decades. The findings suggest that the cumulative effects of high-volume injection to the south have had an extended influence on fluid pressure in the pores of subsurface rocks.

This regional pressure change has the potential to trigger earthquakes far from the high-volume injection points, especially in areas where fluid pressure may already be elevated from local injection operations.

Human Activity and Earthquakes

Published studies have long indicated that human activity can cause earthquakes. Such earthquake-inducing processes include fluid injection for enhanced oil recovery, solution mining, hydraulic fracturing, geothermal stimulation, and disposal of waste fluids from industrial or oil and gas operations [Ellsworth, 2013].

Fluid injection into deep wells can increase underground pore pressure sufficiently to overcome frictional resistance and trigger slip on faults in the crystalline basement rock near an injection site, especially where large crustal stresses have brought a fault close to failure [Nicholson and Wesson, 1990].

Most induced earthquakes are too small to be felt. However, if a fault of sufficient length is subjected to the right stress conditions, the potential exists for triggering an earthquake with ground motion large enough to cause damage. This potential is a concern for both the public and the state agencies that regulate injection wells.

Wastewater Disposal in Deep Wells

Over the past decade, innovations in horizontal drilling and hydraulic fracturing technologies have helped drive interest in extracting oil and gas from the Mississippian limestone in Kansas and Oklahoma. Oil and gas production began to rise in Oklahoma in 2009, followed by Kansas in 2012.

This earthquake hazard map shows that Kansas is generally at low risk (blue areas) for damaging ground motion from earthquakes. However, high-volume saltwater disposal near the southern Kansas border could potentially increase this risk in the south central part of the state. Credit: USGS, modified from Petersen et al. [2014]The extraction process from the Mississippian limestone produces large volumes of highly saline formation water, which is typically disposed of in deep saltwater disposal wells. Initially, operators of many newly completed disposal wells were permitted to inject fluid into the ground at rates 3 to 4 times historic levels.

Most of these high-volume wells inject fluid into a rock formation called the Arbuckle Group, made up of highly permeable Cambrian-Ordovician age sedimentary rocks. With no underlying confining layer in many places, these rocks are hydraulically linked to the Precambrian granite basement that lies below. Such basement rocks typically have many faults, mapped and unmapped, but generally with sparse historical earthquake activity.

Oklahoma and Kansas Earthquakes

Kansas and Oklahoma are located in a tectonically stable region with low risk for damaging natural earthquakes. Before 2009, both states had a history of seismic activity with an average of one to two earthquakes of magnitude 3 or larger occurring annually.

A historically unprecedented increase in the rate and magnitude of earthquakes followed the dramatic rise in saltwater disposal in the area. Oklahoma began experiencing an unusually large number of earthquakes in 2009, followed by south central Kansas in 2013.

Fig. 1. On this map of Kansas, dark dots show locations of earthquakes reported by the U.S. Geological Survey and the Kansas Geological Survey from 1977 to 2012; orange dots indicate earthquakes reported by the USGS from 2013 to 2014. Nearly all of the recent earthquakes occurred within two southern counties (Harper and Sumner), which have seen a large increase in high-volume fluid injection. Light green areas show prominent subsurface geological structures.

In 2014, the U.S. Geological Survey (USGS) reported 42 earthquakes of magnitude 3 or larger in Kansas, including a magnitude 4.9 tremor, the largest recorded in Kansas using modern instruments. All but a few epicenters were located within five distinct zones in Harper and Sumner counties, a part of the state with few reported earthquakes in previous years (Figure 1).

Fluid Injection in Kansas

Numerous industries in Kansas use underground injection control wells for fluid disposal. The state currently manages 50 deep industrial wastewater wells (Class I), regulated by the Kansas Department of Health and Environment, and approximately 5,000 saltwater disposal wells (Class II), regulated by the Kansas Corporation Commission.

Cumulative injection volumes in most areas of the state have been consistent for the past several years. However, by far the most dramatic change in approved volume increases occurred in south central Kansas. The annual saltwater disposal volume in Harper County alone increased from the historic rate of about 10 million barrels to more than 100 million barrels by 2015.

In response to the increased earthquake activity in south central Kansas, Governor Sam Brownback in January 2014 appointed a task force consisting of representatives from the Kansas Geological Survey (KGS), Kansas Department of Health and Environment, and Kansas Corporation Commission to consider the matter. The task force developed a response plan for mitigating induced earthquakes and recommended enhanced seismic monitoring.

Monitoring Seismic Activity

In early 2015, KGS installed six temporary seismograph stations in south central Kansas to closely monitor and better understand the seismic activity. During the first 6 months of monitoring, earthquake epicenters persisted in dense clusters primarily within the same high-seismicity zones identified in 2014.

A member of the Kansas Geological Survey field crew installs a seismic station in south central Kansas. Credit: Shelby Peterie

Conversations with the Oklahoma Geological Survey and Oklahoma Corporation Commission made it clear that restrictions on individual disposal wells did not always reduce seismic activity. Indeed, the majority of the Oklahoma and Kansas earthquakes do not directly correlate with injection operations at a single nearby well. Rather, the widespread seismicity appears to be a result of cumulative injection in numerous disposal wells [Walsh and Zoback, 2015].

Hence, the Kansas Corporation Commission took a geologically based mitigation approach designed to reduce pore pressure around known active fault zones.

Earthquake clustering was used to identify likely basement structures sensitive to changes in deep fluid pressure. The commission ordered reduced injection volumes for saltwater disposal wells located within a set of ellipses defined around the high-seismicity zones in Harper and Sumner counties. By July 2015, saltwater disposal rates were reduced to near the maximum historic rate in the area prior to the uptick in earthquakes.

Earthquake Migration

A year after saltwater disposal volumes were restricted, earthquake activity within the injection-restricted footprint dropped dramatically. Only about 250 earthquakes of magnitude 2 or larger were recorded in 2016, compared to nearly 800 in 2015 (Figure 2).

Fig. 2. Earthquakes recorded by the Kansas Geological Survey network in Harper (HP) and Sumner (SU) counties showed a sharp decrease between (a) January to June 2015, prior to the Kansas Corporation Commission’s order restricting fluid injection volumes, and (b) July to December 2016, a year after the order went into effect. The ellipses show the zones where the Kansas Corporation Commission restricted injection volumes. Credit: Modified from Peterie et al. [2017]Fig. 3. Nearly 7,000 earthquakes (gray) were recorded by the Kansas Geological Survey seismic network in Harper (HP), Sumner (SU), Sedgwick (SG), and Reno (RN) counties from January 2015 through June 2017. Shaded blue circles represent the concentration of earthquake epicenters at 6-month intervals and demonstrate the progression of earthquakes with time to the north and northeast. Injection rates for industrial injection wells (red crosses) in some counties with recent earthquake swarms have remained consistent for years, if not decades. Credit: Modified from Peterie et al. [2018]However, earthquake epicenters began gradually migrating into other areas at increasingly greater distances from the initial high-seismicity zones. This earthquake migration followed a distinct northern progression, often along linear trends that suggest fault zones [Peterie et al., 2018]. By early 2017, earthquakes had advanced more than 50 kilometers from Harper and Sumner counties into neighboring counties with a history of minimal earthquake activity (Figure 3).

This unexpected migration does not fit the traditional model of induced seismicity, where locally elevated pressure triggers earthquakes near the causal well. Owners of industrial injection wells (Class I), which had previously operated for years without incident, became concerned that they would be held responsible for earthquakes in their areas and required to stop injection operations.

As a result, the Kansas Department of Health and Environment intensified a longstanding wastewater reduction effort for these industrial wells. By 2017, some facilities had already implemented comprehensive wastewater reduction programs, and most were continuously refining their processes to reduce wastewater disposal.

Regionally Elevated Fluid Pressure Equipment on a data logging truck records fluid pressure at the bottom of the deep hole of an industrial wastewater injection well in Kansas. Such measurements show unexpectedly widespread increases in pore pressure in parts of the state as far as 90 kilometers away from high-volume saltwater disposal wells used to inject extracted oil field brine in southern Kansas and northern Oklahoma. This regional pressure change accompanies a sharp rise in the incidence of earthquakes in areas that previously rarely experienced seismic activity. Credit: Bob Fisher

Numerous studies suggest that a pressure increase of as little as 0.01 to 0.2 megapascal along a critically stressed fault may be sufficient to trigger an earthquake (by comparison, the air pressure in a car tire is usually about 0.2 megapascal) [e.g., Keranen et al., 2014].

Measurements of pressure at the bottom of wells (bottomhole pressure) that terminate in the Arbuckle Group can provide insight into fluid pressure affecting basement faults. Facilities with active Class I wells, all but one of which terminate in the Arbuckle Group, are required to measure and report bottomhole pressure to the Kansas Department of Health and Environment annually. Bottomhole pressure is not reported for saltwater disposal (Class II) wells, which are subject to different regulatory requirements.

Historically, most Class I facilities meas­ured only small (on the order of 0.05 megapascal) annual bottomhole pressure fluctuations with a relatively flat multiyear trend. Beginning in 2012, increasing bottomhole pressure was measured at several facilities across central Kansas. The most dramatic increase was observed at the southernmost facility located in Harper County, where by 2016 pressure had increased more than 0.4 megapascal relative to historic pressures (Figure 4).

Similar, but smaller, pressure increases were observed in Sedgwick and Reno counties near areas where earthquakes had advanced in 2016 (Figure 3).

A particularly revealing trend was observed at three facilities in Reno County located within 10 kilometers of an earthquake cluster. Although these facilities inject vastly different disposal volumes and they were 5 to 10 kilometers apart, the bottomhole pressure trends were nearly identical, rising about 0.2 megapascal in the past few years (Figure 5).

Fig. 4. Preliminary map of the pressure change measured in Class I industrial wastewater disposal wells in 2016 relative to 2002 baseline measurements. Fluid pressure in the Arbuckle Group has increased across south central Kansas and is most prominent in Harper (HP) County, which experienced a sharp increase in high-volume saltwater disposal starting in 2012. MPa = megapascals.

Because annual injection volumes in these and other nearby wells have been consistent for about a decade, it seems highly unlikely that local injection practices alone are responsible for the abrupt and unprecedented increase in formation pressure and seismicity.

Far-Reaching Effects

The combination of regionally elevated Arbuckle Group fluid pressure (most prominent to the south), gradual northward progression of earthquake trends well outside the initial high-seismicity zones, and lack of commensurate changes in local injection volumes supports the hypothesis that the observed pressure increases are predominantly influenced by regional increases in high-volume injection as far as 90 kilometers to the south.

It is not surprising that seismic activity has increased in counties with elevated bottomhole pressure. What is surprising is that the observed rise in bottomhole pressures does not appear to correlate with local (within 20 kilometers) injection volumes in or near the wells where these measurements were made. Rather, the rise in fluid pressure closely tracks significant increases in saltwater disposal volumes several counties to the south.

This observation is notable because the largest previously reported distance between a causal well and an induced earthquake (and thus critically elevated pore fluid pressure) is about 20 kilometers [Keranen et al., 2014].

Twofold Effect Fig. 5. Changes in bottomhole pressure (relative to baseline) measured at three Class I facilities in Reno County followed nearly identical trends despite the 5- to 10-kilometer separation between facilities and vastly different injection volumes.

Although it is unprecedented to suggest injection practices could influence fluid pressure and seismic activity much more than 20 kilometers away, the volume of fluid injected into this formation is also unprecedented (Figure 6).

A study of the central and eastern United States found that an earthquake is statistically more likely to occur near wells injecting more than 300,000 barrels per month than near wells injecting at lower rates [Weingarten et al., 2015]. In an area about the size of two counties that spans both sides of the Kansas-Oklahoma border, nearly 50 saltwater disposal wells were each injecting at or above this rate in 2015. Most widely recognized cases of induced seismicity had one or, at most, a few wells injecting near this rate.

The effects of such high-volume injection appear to be twofold. Pressure is locally elevated near a high-volume well shortly after injection begins. This local pressure change directly affects nearby faults and is likely the dominant factor influencing induced earthquakes.

Fig. 6. Volume of fluid injected into the Arbuckle Group in Class II saltwater disposal and Class I wells in Kansas and Class II saltwater disposal wells in Oklahoma in 2015. MMbbl = million barrels.

Far-field pressure increases occur as a cumulative effect resulting from fluid migration and pressure diffusion from high-volume injection wells along high-permeability pathways, such as permeable fault zones. Because highly detailed fault maps do not exist for south central Kansas and hydraulic properties can vary widely, predicting fluid flow and migration rates away from an injection site is difficult, at best.

Like local pressure, far-field pressure diffusion triggers earthquakes only where pore fluid pressure exceeds the critical pressure for initiating slip on an appropriately stressed fault. As fluid moves into areas where pressure is locally elevated because of nearby injection operations, a minimal pressure increase may be sufficient to raise absolute pore pressures above the triggering threshold.

This may explain why earthquake swarms have developed in areas with a long history of fluid injection but with no previously known injection-induced earthquakes.

Regulatory Challenges

Because fluid disposal is widespread and generally involves multiple operators regulated by different agencies within the same state and across state borders, developing equitable practices to minimize increased formation pressures poses unique challenges for regulators.

Regulatory actions to reduce distant high-volume disposal may take months or years to affect far-field pressure.Mitigation of earthquakes caused by local high-volume injection is relatively straightforward: Reduce injection volumes near critically stressed faults sufficiently to reduce pressure below the triggering threshold, and local seismic activity will decay.

Mitigating earthquakes caused by far-field pressure diffusion is more complex. Just as it took months or years before distant high-volume disposal practices raised the far-field pressure above the triggering threshold, regulatory actions to reduce distant high-volume disposal may take months or years to affect far-field pressure.

In addition, because far-field pressure from distant injection combines with local injection pressure to elevate local pressures beyond the earthquake-triggering threshold, seemingly independent injection operations may contribute to triggering earthquakes.

A Cooperative Approach

After recognizing the synergistic effects of local and far-field pressure changes, the Kansas Corporation Commission and Kansas Department of Health and Environment, the two state agencies that regulate injection wells, met with the KGS to discuss the agency’s findings.

Industries currently use Arbuckle Group disposal wells for everything from drinking water treatment to oil production and refinement, each of which has unique operational processes, business models, and stakeholders. Not only do two separate agencies regulate injection wells, but the diversity of industries performing Class I and Class II injection operations, ownership of mineral rights as well as other legal and regulatory issues, and movement of fluids across state lines add to the complexity of seeking efficient solutions.

Both regulating bodies are currently providing data to and meeting with the KGS regularly in a collaborative effort to develop and implement recommendations. Joint policies between state agencies to address injection volumes and establishment of other best management practices would be an equitable and effective approach to mitigate induced seismicity from regional pressure changes.

Data used in this study can be found in the supporting information of Peterie et al. [2018].  Injection volumes for Oklahoma Class II wells are provided by the Oklahoma Corporation Commission.

Acknowledgments

We are grateful to John Intfen and Julio Gonzales for data analysis and to the KGS field crew for installation and maintenance of the KGS seismic network.

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Radiocarbon in the Oceans

Tue, 04/17/2018 - 12:01

Radiocarbon dating is a technique used in diverse disciplines including environmental science, archaeology, and biomedicine. In the geosciences, the processes by which radiocarbon is produced and cycled through the oceans, atmosphere, and biosphere are broadly understood but there is significant variability in radiocarbon concentrations over space and time. In an article recently published in Reviews of Geophysics, Alves et al. [2018] present the latest status of research on the marine radiocarbon reservoir. Here the authors answer some questions about marine radiocarbon and its variability.

What are the different reservoirs of carbon on Earth and how does carbon move between them?

The Earth’s carbon reservoirs are distributed within the lithosphere, hydrosphere, and biosphere. In fact, even tiny microbes are carbon reservoirs, but scientists tend to group small reservoirs into larger categories (e.g., ocean, atmosphere, biosphere), important at the global scale.

Each compartment in the global carbon cycle stores and recycles carbon, but the magnitude of the storage and the rate of exchange vary enormously between them. Carbon stored in the atmosphere, surface ocean, biomass and soils, for example, is cycled relatively quickly via processes such as photosynthesis, respiration, decomposition, and air-sea gas exchange.

Inventories such as the deep ocean, sediments and rocks, on the other hand, store huge amounts of carbon accumulated over thousands to millions of years, but the fluxes of carbon in these reservoirs are comparatively very slow and occur via processes such as sedimentation and volcanic eruptions.

Is there a difference between terrestrial and marine radiocarbon levels?

Yes. Radiocarbon (14C) is produced in the atmosphere; the transfer of these atoms into the ocean occurs at the air-sea interface, and is controlled by factors such as wind speed and temperature. In the deep ocean, 14C can reside for about 1,000 years before upwelling returns carbon to the surface. Thus, air-sea gas exchange paired with slow internal mixing in the oceans lead to a disequilibrium in radiocarbon activity between the atmosphere and the ocean, which is known as the Marine Reservoir Effect (MRE).

Some of the mechanisms impacting the radiocarbon marine reservoir effect in a coastal region. Credit: Alves et al., 2018, Figure 4

It is important to mention that these processes are not uniform over the global ocean and thus the disequilibrium is not only between ocean and atmosphere, but there are also differences in radiocarbon levels within the ocean. The transfer of radiocarbon into the ocean can be favoured in some regions (CO2 sinks) and hindered in others (CO2 sources). Moreover, carbon makes its way into the ocean by a variety of other processes such as continental runoff, in which case the 14C levels of the estuary reflect a mix between ocean waters and freshwater.

How does ocean radiocarbon concentration vary over space and time?

The ocean radiocarbon concentration responds to the factors controlling the MRE, such as the air-sea gas exchange and ocean dynamics. These phenomena, in turn, respond to climate factors such as temperature, wind speed and sea-ice cover. Thus, whenever there is a spatial or temporal variation in any of these parameters, the MRE varies accordingly. Depending on the phenomenon considered, these variations can happen at different time and spatial scales. We know, for instance, that the increase of sea-ice cover in the North Atlantic during the Younger Dryas climatic event hampered the air-sea gas exchange, and was one of the causes for an increase in the magnitude of the MRE.

Current values for the MRE worldwide. Credit: Alves et al., 2018, Figure 7

How do scientists take this difference into account?

It depends on the research objectives. The MRE can be used as a proxy for its controlling factors so scientists can measure the MRE magnitude to understand such phenomena and disentangle processes of ocean circulation and its spatiotemporal changes, for example. Archaeologists and other scientists, who are more interested in the radiocarbon dating tool per se, quantify the MRE in their study region and apply the correction in the calibration of marine radiocarbon ages from that particular place.

What are some of the unresolved questions in this field where additional research, data or modelling is needed?

The question of the dominant control on the MRE in different localities is still a subject of debate. More empirical data is needed to reconstruct spatiotemporal changes in the MRE, allowing model calibration and correlation with a changing climate. For the calculation of MRE offsets from archaeological contexts, there is a lack of robust protocols to assure sample suitability. Moreover, the radiocarbon community has suggested the use of local calibration curves to better account for regional MRE offsets in the heterogeneous ocean reservoir, but a reasonable method for their construction has not yet been proposed.

—Eduardo Queiroz Alves, Oxford Radiocarbon Accelerator Unit, University of Oxford, UK; email: eduardo.queirozalves@arch.ox.ac.uk

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Thousands Take to the Hill to March for Science

Mon, 04/16/2018 - 19:34

“If we ignore or denigrate science, we do so at our own peril.”“Science is what separates facts from fallacies, falsehoods, and fanaticism,” retired rear admiral and former oceanographer of the U.S. Navy David Titley declared to thousands of science supporters on the Mall in Washington, D. C., on Saturday. “Science tells us what we know, what we don’t know, and how to expand those frontiers of knowledge. If we ignore or denigrate science, we do so at our own peril.”

Titley’s comments during a public rally near the Washington Monument helped set the tone for the second March for Science in as many years. Titley, a professor of meteorology and director of the Center for Solutions to Weather and Climate Risk at the Pennsylvania State University in University Park, and other scientific leaders helped to highlight the importance of science and to fan enthusiasm among demonstrators assembled in the U.S. capital. Many thousands of additional science enthusiasts demonstrated in roughly 230 satellite marches around the globe on Saturday, with events taking place on every continent.

The demonstrations occurred at a time when many in the scientific community perceive themselves as disregarded, marginalized, and threatened by potential funding cuts and harmful government interference. Not only were scientists and science advocates marching to increase support and protect funding, they were also trying to get across the messages of the value of science and the scientific method to society, to democracy, and to the entire population.

Triggered by Trump

“Do not expect science to speak for itself. We must [speak for it] with whatever megaphones that we can.”Donald Trump’s successful election campaign in 2016 and his administration’s first-year agenda, which many have judged to be antiscience, antienvironment, and antiprogress, spurred the first March for Science demonstrations last year on a cold, rainy Earth Day. Favored by sunny, warm weather this time around, this year’s rally likely drew fewer people than last year’s. Nonetheless, the messages of last year’s rally were reemphasized this year.

Rush Holt, CEO of the American Association for the Advancement of Science, called on the scientific community to remain vigilant in the fight to protect science. “Do not expect science to speak for itself,” he said during the premarch rally. “We must [speak for it] with whatever megaphones that we can.” He continued, “Science is society’s best friend, our government’s best friend. It’s civilization’s best friend.”

Among the rally’s attendees, paleontologist Arnie Miller of the University of Cincinnati, Ohio, and the current president of the Paleontological Society of America, told Eos that the sense of peril since Trump took office prompted the scientific society for the first time to establish a government affairs department. Those who don’t monitor government activity these days may be in for unpleasant surprises, he noted. “We’re bringing our periscopes up,” Miller said.

A Call for Diversity

“We desperately need a scientific community that will reflect the demographics of our nation.”Also speaking to the D. C. rally was “Dreamer” Evelyn Valdez-Ward, who was brought into the United States illegally from Mexico as a child and today faces possible deportation after President Trump threatened to suspend a policy directive issued by former president Barack Obama, known as Deferred Action for Childhood Arrivals, or DACA. The policy protected Valdez and hundreds of thousands of other undocumented immigrants who were brought to the United States as children, popularly known as “Dreamers.”

Valdez is not just a Dreamer but a future scientist, too. She studies the effects of drought on plants and soil microbes in the graduate program at the University of California, Irvine. “Dreamers are doing the science that will bring this nation to the next level,” she told the rally. “This fight is not just about us, but it’s also about this nation losing prospective students because we stand to lose talented minds if they don’t find support here. We desperately need a scientific community that will reflect the demographics of our nation.”

The Rallies Commence

Spurred by the rally’s speakers, the crowd of proscience demonstrators, bristling with signs, began striding down Constitution Avenue toward the grounds of the U.S. Capitol chanting “Science not silence!”; “What do we want? Science! When do want it? After peer review!”; and other slogans.

#MarchForScience @ScienceMarchDC pic.twitter.com/xlZORKEyvS

— S&TPolicyFellowships (@AAAS_STPF) April 14, 2018

In addition to the protest at the U.S. Capitol, more than 100 registered satellite demonstrations took place in the United States, spanning most states and territories, including Guam and the Virgin Islands. Although many participants were protesting the current administration’s agenda, others encouraged public trust in science, emphasized scientific contributions to the world, and defended science education in schools. And in about 100 more locations, thousands gathered in support and defense of science at satellite marches on all continents, including Antarctica.

Check back later for Eos’s selected snapshots of March for Science signs around the world.

—Kimberly M. S. Cartier (@AstroKimCartier), Staff Writer; and Peter L. Weiss, Senior News Editor

Editor’s note: The American Geophysical Union (AGU) was a formal sponsor of the 2018 March for Science.

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Tailoring Aerosol Injections to Achieve Desired Climate Effects

Mon, 04/16/2018 - 12:03

It’s widely accepted that voluntary emissions reductions alone will not be enough to reach the goal of the 2016 Paris agreement to keep this century’s global temperature increase below 2°C, leading some policy makers and scientists to argue that geoengineering techniques should also be considered to limit the impacts of global warming. One proposed technique involves injecting reflective sulfate aerosol particles into Earth’s lower stratosphere to cast a small proportion of the inbound sunlight back into space and cool the planet off.

Yet geoengineering proposals that intentionally manipulate the amount of light reflected by Earth’s surface—or albedo—are not sufficiently understood. The potential risks around sulfate aerosol solar geoengineering include alteration of regional precipitation patterns, its effects on human health, and the potential damage to Earth’s ozone layer by increased stratospheric sulfate particles.

Previous research exploring the climate’s response to aerosol injection scenarios has suggested that these methods could be tailored to reduce the potential side effects. No studies have systematically explored the extent of such control, however, in part because of the computational expense of running general circulation models with comprehensive aerosol chemistry. To provide guidance for future high-resolution simulations, Dai et al. used a computationally cheaper, two-dimensional chemical transport model to systematically estimate the effects of injecting sulfur dioxide and sulfate aerosols at a range of altitudes, latitudes, and time frames for 62 separate scenarios.

The results indicate that aerosol injections can be carefully tailored to achieve desired results, such as a minimal albedo increase near the equator, rather than a globally uniform response. For example, the simulations show that equatorial injections of sulfuric acid at high altitudes—where aerosols have a longer residence time—are the most effective at reflecting incoming radiation per unit of sulfur. They also indicate that sulfate aerosol has a higher efficacy than sulfur dioxide in all injection scenarios. In addition, the findings suggest that different injection scenarios may be combined to achieve specific climate objectives.

Although the authors caution that their results are approximations intended to guide future modeling efforts, this study provides fundamental information regarding the relative difficulty of achieving desired albedo modification effects and is an important starting point for understanding the limits of what is widely considered one of the most viable solar geoengineering techniques. (Geophysical Research Letters, https://doi.org/10.1002/2017GL076472, 2018)

—Terri Cook, Freelance Writer

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Playing Their Way into the Geosciences

Mon, 04/16/2018 - 12:01

Undergraduate students in an average geology class have a wide range of spatial skills, according to a new study that tested the abilities of hundreds of students. The researchers found that the students’ scores in tests of those skills correlated with certain life experiences, including types of play as children.

Because women are underrepresented in the geosciences workforce, the researchers paid close attention to gender disparity in spatial skills. They found that one specific life experience removed the difference in test scores between male and female students: frequent playing with construction-based toys. This finding illustrates that spatial reasoning differences between males and females come from experiences rather than biology, the authors argue in a recently published paper about their new work.

“We’re trying to see how we can level the playing field to give everyone the same chance and really make sure there are no structural barriers [against] participating in geosciences,” said Anne Gold, the education and outreach director at the Cooperative Institute for Research in Environmental Sciences in Boulder, Colo., and lead author of the new study.

Gold and her colleagues reported their results in Geosphere in February.

Establishing the Baseline

The first step to discovering structural barriers in university-level geoscience education, Gold explained, is determining the range of spatial ability in early undergraduate students.Spatial reasoning is the ability to mentally manipulate visual images: rotating objects in one’s mind, for example. Researchers have established that having high spatial ability is a key skill for science, technology, engineering, and math (STEM) disciplines and generally a predictor of success in STEM careers, according to Gold. For example, chemists analyze the three-dimensional shapes of molecules and how they interact physically.

The first step to discovering structural barriers in university-level geoscience education, Gold explained, is determining the range of spatial ability in early undergraduate students. To assess that range, the researchers gave timed tests to 277 undergraduate students enrolled in an introductory geology course at a U.S. university with a student population of more than 30,000. The tests covered three different spatial skills related to the ways in which parts of an object fit together, including the mental rotation of a three-dimensional structure from one angle to another. Because many students take this course to fulfill their science requirements, the studied group has a broad mixture of STEM and non-STEM majors.

The researchers also collected data on the tested students: demographic information such as gender, academic background such as past coursework and declared major, and play experiences. After students took the tests, they completed a survey where they reported their childhood play experiences with video games, construction-based toys, and sports. The researchers chose these categories on the basis of past studies connecting them with spatial thinking training. They considered adding other activities to the survey, including craftwork like sewing, but they struggled to develop quantifiable questions around these strongly gender biased skills, explained Gold.

Gender Differences

The resulting test scores varied from 6% to 75% correct. “It’s just an enormous range,” said Gold. She noted that such a wide range in one of the core skills for STEM fields makes it difficult for instructors to teach and for students to learn. A split between males and females was also obvious in the scores, especially in the mental rotation test.

Students who reported playing frequently as children with construction-based toys, such as blocks and connectors, had higher spatial thinking scores.However, unlike past studies, this new research aimed to determine whether life experiences that may have trained test subjects’ spatial reasoning could explain the scores’ distribution. Using regression modeling to look at the possible correlations, Gold and her colleagues found that they were able to explain nearly a quarter of the variability in the scores, which Gold noted is significant in the social sciences.

The modeling showed, unsurprisingly, that students who reported playing frequently as children with construction-based toys, such as blocks and connectors, had higher spatial thinking scores. In addition, students who self-reported playing action, construction, or sports video games in childhood scored higher on the tests. But a closer look at which traits correlated the most strongly with spatial proficiency showed that it was frequent playing with construction-based toys not gender that drove high performance.

Bigger Picture

The new findings don’t conclusively rule out gender as a factor in spatial ability. Julie Libarkin, head of the Geocognition Research Laboratory at Michigan State University in East Lansing who edited the submitted manuscript before publication, praised the new study as an example of research others should strive for. However, she said, the findings remain nuanced, and she would like to see the research taken further. “It’s not clear that the difference in spatial skill is the result of playing with construction-based toys or if playing with construction-based toys is the result of having certain spatial skills,” she says. “It’s the chicken or egg question.”

Researchers found that students with higher spatial skills self-reported that they preferred playing video games in the action, construction, and sports categories. Credit: scottdunlap/iStock/Getty Images Plus/Getty Images

With studies like this one, “we’re getting to a place…in geosciences education research where can we start to ask more fundamental questions that drive at why and how people are successful in STEM fields and in geosciences in particular,” said Eric Riggs, a geology and geophysics professor at Texas A&M University in College Station who was not involved with this spatial skills study.

However, the work also raised additional questions for him. “I’m always interested to see if the same thing holds true in other places around the world or around the country at least,” he said. “Is this just a general human phenomenon, or are we just seeing a small snapshot through a single university?”

Trainable Spatial Skills

Gold acknowledged the limitations in the study and agreed that the general population could display even larger differences in spatial reasoning. She said that testing a more general population could provide more opportunities to increase the pool of future geoscientists.

In the meantime, Gold said she hopes parents and especially K–12 educators are inspired by these research results. “Maybe [we should be] more strategic than we have been in the past in supporting spatial training at all different levels of our life, starting at play age,” she said.

“Anyone can become a geoscientist.”Undergraduate students with low spatial skills shouldn’t feel discouraged about entering STEM fields. The baseline results are informing Gold and her colleagues on how to design training to increase those skills.

Libarkin agreed, saying that any group of scientists has a range of abilities and even if one skill level is low, a scientist can learn workarounds. “Anyone can become a geoscientist,” she said.

—Laura G. Shields (email: lgshields@gmail.com; @LauraGShields), Science Communication Program Graduate Student, University of California, Santa Cruz

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Australian Algae Aid Understanding of Ecosystem Resilience

Fri, 04/13/2018 - 11:31

In 1973, the renowned Canadian ecologist C. S. Holling introduced the idea of ecosystem resilience. An ecosystem’s resilience refers to its ability to withstand environmental pressures, or perturbations—such as fires, floods, storms, deforestation, fracking, pesticide spraying, or the introduction of an invasive species—and the time it takes for the ecosystem to return to a stable, functioning state. According to Holling, all ecological systems go through cycles of good and poor health. Scientists study these cycles in detail to better understand and predict the overall health of an ecosystem.

In a new paper, Beck et al. examined a shift in an ecosystem to a stable state that can occur in response to a perturbation. Such shifts are known as “critical transitions,” and they are often sudden and unpredictable—examples include an influx of nutrients, a land use change, or a change in climate. The team identified a series of early warning signals that if detected in time, can alert observers to an impending critical transition.

Detecting these signals, such as a lowered resilience or a sluggish recovery time, can be challenging. This is especially true for ecosystems with long generational life spans, such as temperate forests, some of which have trees that are thousands of years old. Knowing this, the researchers decided to use paleoecological data, which provide ecological data over long timescales.

Using paleoecological data collected from a meter-long core extracted in 2011 from Australia’s Lake Vera in Tasmania, the researchers examined the interrelated changes in vegetation, pollen, charcoal, soil, and other components of the sediments over the past 2,400 years. In particular, they investigated the impact of fire, a major driver of ecosystem changes on land, on the aquatic ecosystem. Aquatic ecosystems, generally speaking, are highly sensitive and respond rapidly to environmental pressures.

Lake Vera is home to a thriving community of a species of diatom, or alga, called Discostella stelligera. The researchers found that the diatom community experienced a critical transition about 820 years ago that was likely caused by wildfires disrupting local vegetation around the same time. They also found that an increased rate of change, as well as increasing shifts in species composition—more oligotrophic (nutrient-poor) and acidic species of diatoms began to replace existing species—had preceded this critical transition.

This study shows that a disturbance on land, such as a wildfire, can drive a critical transition in a lake within that ecosystem. It also illustrates several early warning signals, namely, rate of change and variability of species composition, that scientists can potentially use to predict critical transitions in an ecosystem. The study also highlights the important role of paleoecological data, which provide evidence for ecosystem changes due to critical transitions and for distinguishing these changes from other kinds of abrupt change. This may also help researchers to understand the parameters that can be used to identify and measure early-warning signals with greater precision. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1002/2017JG004135, 2018)

—Sarah Witman, Freelance Writer

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Catching the Oncoming Radiation Storm

Fri, 04/13/2018 - 11:29

Solar radiation storms enhance radiation levels in Earth’s atmosphere. There is growing interest in detection of these events because of the recognition that enhanced atmospheric radiation is a significant risk to civil aviation (it can disrupt avionic control systems, and also deliver human radiation doses that may require post-event assessment and advice by medical experts). He and Rodriguez [2018] compare two very different methods for detection of these storms. One is the use of ground-based measurements to detect the enhanced fluxes of atmospheric neutrons produced during such events; the other is use of space-based sensors to detect the enhanced fluxes of solar energetic particles that cause such events (those particles must have sufficient energy (>400 MeV) to penetrate deep to Earth’s atmosphere and generate atmospheric neutrons). The authors show that, when carefully analyzed, the two techniques are evenly matched in terms of the speed with which they can detect these events. Thus they suggest that the development of future monitoring systems should consider both techniques, perhaps combining the two so as to exploit their different strengths.

Citation: He, J. & Rodriguez, J. V. [2018]. Onsets of solar proton events in satellite and ground level observations: A comparison. Space Weather, 16. https://doi.org/10.1002/2017SW001743

—Michael Hapgood, Editor, Space Weather

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Former EPA Chief Decries Attacks on Science

Thu, 04/12/2018 - 18:38

Former U.S. Environmental Protection Agency (EPA) director Gina McCarthy said on Tuesday that it is important to stand up for science against attacks by the Trump administration.

“This attack on science is ludicrous. It is simply a short-term way for this administration to deny reality, so they can do whatever they want, and right now that just appears to be what industry wants them to do.”“This attack on science is ludicrous,” McCarthy, who served as EPA administrator under President Barack Obama, told Eos in an interview. “It is simply a short-term way for this administration to deny reality, so they can do whatever they want, and right now that just appears to be what industry wants them to do.”

McCarthy spoke to Eos following an event she participated in at National Geographic Society headquarters in Washington, D. C., to help launch Resource Watch, a technology platform devised by the World Resources Institute and its partners to monitor global resources and trends.

Many scientists and environmentalists have criticized the Trump administration for attacking and sidelining science and for rolling back environmental regulations. McCarthy spoke a few days before thousands of scientists and other citizens around the nation and world are expected to rally in support of science at March for Science events this Saturday. The American Geophysical Union, publisher of Eos, is a sponsor of the March for Science internationally.

“Science is really important. It is the backbone of the success of this country,” McCarthy said. “It’s how we are going to figure out how to have a sustainable and healthy planet and ecosystem and economy.”

The attack on science “worries me a lot,” she added. “It worries me because I work at the Harvard School of Public Health, and [science] is what we rely on to provide people real information on what matters to them to protect themselves and their families.”

McCarthy, who was EPA administrator from 2013 to 2017, directs Harvard’s Center for Health and the Global Environment in Boston. “I also work for a private equity company called Pegasus Capital. They actually want to rely on science. The business community needs it,” she noted.

McCarthy’s Perspective on EPA

McCarthy said that it’s hard for her to tell, from the outside, how much Pruitt might be weakening the agency’s role in protecting the environment. Recent news stories have reported that some of Pruitt’s regulatory rollback efforts are poorly devised and may not hold up in court. “I do know that they have budget challenges. I know some good people have left,” she said.

The current administration has consistently tried to slash the agency’s budget. On 23 March, President Donald Trump reluctantly signed the 2018 omnibus spending bill, which provides level funding for EPA for fiscal year 2018.

“My only hope is that [Pruitt’s] inability to work with the career staff and to focus on the mission of the agency will make him much less effective at dismantling the agency or rolling back really important public protections,” McCarthy told Eos.

On Ethics Concerns at EPA

EPA “is an agency whose mission is important. [Pruitt] should be focused on it. So far, not so good.”Regarding how much Pruitt might be weakened by current ethical questions about his travel expenses, housing arrangements, and other issues, McCarthy responded,  “I really can’t tell because I don’t know what his intent is. But I know a couple of things. One is that [EPA] is an agency whose mission is important. He should be focused on it. So far, not so good,” she said.

She emphasized, however, that “the most important thing I think right now is to get good information out to people and to not allow science to be attacked, but to stand up for it and speak as clearly as we can.”

—Randy Showstack (@RandyShowstack), Staff Writer

The post Former EPA Chief Decries Attacks on Science appeared first on Eos.

Study Proposes Link Between Supercontinents, Ocean Tides

Thu, 04/12/2018 - 12:28

The cyclic strengthening and weakening of ocean tides over tens of millions of years is likely linked to another, longer cycle: the formation of Earth’s supercontinents every 400 to 600 million years, according a new study. The new findings have implications for the formation of our planet, its climate and the evolution of life on Earth, according to the study’s authors.

The new research suggests long-term changes in tidal energy, which control the strength of the ocean’s waves, are part of a super-tidal cycle dictated by the movement of tectonic plates.

When tectonic plates slide, sink and shift the Earth’s continents to form large landmasses, or supercontinents, ocean basins open and close in tandem. As these basins change shape, they can strike forms that amplify and intensify their tides.

In the new study, tidal simulations projected hundreds of millions of years into the future suggest the Earth is now in the nascent stage of a tidal energy maximum, where strong tides will persist for roughly 20 million years. The oceans will go through several tidal cycles as the next supercontintent forms over the next 250 million years. Eventually, the tides will grow much weaker, just as they did during the two most recent supercontinents: Pangaea and Rodinia, according to the new study published in Geophysical Research Letters, a journal of the American Geophysical Union.

Scientists were aware tidal energy varied in the distant past, but the new study suggests there is a super-tidal cycle occurring over geologic timescales and linked to tectonic movement.

“Our simulations suggest that the tides are, at the moment, abnormally large,” said oceanographer Mattias Green from Bangor University’s School of Ocean Sciences in Menai Bridge in the United Kingdom and lead author of the new study. “And that really was our motivating question: If the tides were weak up until 200 million years ago, and they’ve since shot up and become very energetic over the past two million years, what will happen if we move millions of years into the future?”

Tidal strength is linked to life on Earth and understanding the ocean’s cyclic progression stands to inform scientists’ understanding of evolutionary history, according to the study’s authors. In times of strong tidal energy, like today, strong waves stir the sea, creating the nutrient mixing needed to sustain ocean life. As Earth’s landmasses move slowly toward a supercontinent configuration, the planet’s ocean basins open, eventually forming one unbroken mass of water. Such a sea would have low tidal energy. Weak waves mean there is less nutrient mixing, which could create an oxygen-starved ocean floor largely devoid of life, much like a pool of stagnant water, according to the new study.

The existence of this cycle and its link to tectonic movement stands to inform many disciplines, from evolutionary biology to global nutrient cycling, according to geophysicist Dietmar Müller from the University of Sydney in Australia, who wasn’t involved in the new study.

“It probably doesn’t mean anything to humans now in our lifetime,” Muller said. “But it does enhance our understanding of interactions between plate tectonics, Earth’s climate system, its oceans, and even how the evolution of life is, at least to some extent, driven by this tidal process.”

Changing Continents, Ocean Basins

Each of Earth’s continents ride atop huge slabs of rock known as tectonic plates. These plates shift over hundreds of millions of years, striking different continental configurations along the way.

Tectonic plates dictate the shape and arrangement of continents, but they also determine the shape of ocean basins. As the North American and Eurasian plates drift apart, the Atlantic Ocean between them widens, also changing its shape.

The change in shape of ocean basins causes a change in a property known as resonance. When a basin is resonant, energy from the gravitational attraction of the moon aligns with the length of the ocean basin, causing an amplification of tidal energy.

Green likens resonance to a child on a swing set. A swinging child only needs a small push from an adult, at the right timing, to keep the swing moving higher and higher. “You force it at the same frequency as the natural oscillation, and the same thing happens in the ocean,” he said.

A Tectonic Timeline

In the new study, scientists simulated the movement of Earth’s tectonic plates and changes in the resonance of ocean basins over millions of years.

The new research suggests the Atlantic Ocean is currently resonant, causing the ocean’s tides to approach maximum energy levels. Over the next 50 million years, tides in the North Atlantic and Pacific oceans will come closer to resonance and grow stronger. In that time, Asia will split, creating a new ocean basin, according to the study.

In 100 million years, the Indian Ocean, Pacific Ocean and a newly formed Pan-Asian Ocean will see higher resonance and stronger tides as well. Australia will move north to join the lower half of Asia, as all the continents slowly begin to coalesce into a single landmass in the northern hemisphere, according to the new study.

After 150 million years, tidal energy begins to decline as Earth’s landmasses form the next supercontinent and resonance declines. In 250 million years, the new supercontinent will have formed, bringing in an age of low resonance, leading to low tidal energy and a largely quiet sea, according to the new research.

The new study finds each tidal maximum lasts at most 50 million years and is not necessarily in phase with the supercontinent cycle.

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Testing the Waters: Mobile Apps for Crowdsourced Streamflow Data

Thu, 04/12/2018 - 12:27

Do you drive, bike, or hike by streams on your way to a field site, the office, or home? Are you interested in how streams change through the seasons and years? If so, consider joining a growing crowd of people logging streamflow data using their mobile phones.

Two new projects—CrowdWater and Stream Tracker—focus on crowdsourced hydrologic measurements, and both have recently launched free smartphone applications to facilitate data collection along stream networks.

Increasingly, crowdsourcing provides valuable hydrologic data for research and watershed management.Many of us regularly rely on crowdsourced mobile phone data for traffic conditions, restaurant reviews, and recommended news articles. Environmental scientists use crowdsourcing to map biodiversity, invasive species, phenology, and bird locations [Tweedle et al., 2012]. Increasingly, crowdsourcing is also providing valuable hydrologic data for both research and watershed management [Turner and Richter, 2011; Lowry and Fienen, 2013; Little et al., 2016].

Keeping an eye on the world’s streams is a daunting task. If you added up the length of all the streams around the world, the total would be at least 89 million kilometers [Downing et al., 2012]. Even in regions with good hydrologic monitoring networks, it is unrealistic to monitor all streams with in-stream sensors. Crowdsourcing is a practical method to increase the accuracy of stream maps and expand understanding of when, where, and how streams flow.

Not only do the world’s streams span an immense spatial extent, but many of them require frequent checking to catch them in action. More than half of the global stream channel network is likely intermittent (i.e., the streams do not have flow year-round [Datry et al., 2014]), yet most streamflow monitoring stations are located on perennial streams. In dry regions, almost all streams are intermittent, but even humid regions have intermittent headwater streams. These streams provide surface water supply, groundwater recharge, nutrient storage and cycling, habitats for aquatic and terrestrial wildlife, and support for vegetation communities that stabilize stream banks [Levick et al., 2008]. Existing map layers often classify stream types incorrectly [Fritz et al., 2013], so many areas lack accurate information on intermittent stream locations.

CrowdWater Tracks Hydrologic Variables

The CrowdWater project’s goal is to improve hydrologic forecasts with the help of crowdsourced data that include water level, streamflow, soil moisture, and the flow condition of intermittent streams. This project, which is funded by the Swiss National Science Foundation, also assesses the accuracy of the data, the effectiveness of quality control measures, and how useful citizen science data are to calibrate or improve hydrologic models.

The CrowdWater project uses an approach that is similar to geocaching.CrowdWater data are collected with an app developed by Spotteron, a citizen science app development company based in Vienna, Austria, on behalf of the University of Zurich. The app has been available for Android and iOS since April 2017 and can be used free of charge.

The CrowdWater project uses an approach that is similar to geocaching: Every participant can establish a new station and contribute data for already existing stations. No physical installations or sensors are needed for the measurements. For stream-level measurements, the user takes a picture and uses the app to add a virtual staff gauge to the picture. When that person or another user returns to the site at another time, the user can determine the new water level by comparing the current water level to the virtual staff gauge on the picture.

A CrowdWater user takes a photo of a stream. Adding a virtual staff gauge to the photo using the app enables users to compare stream levels among several photos without the need for physical installations or sensors. Credit: Rolf Klossner

The status of intermittent streams can be recorded using six categories: flowing water, standing water, connected pools, isolated pools, wet streambed, and dry streambed. Measurements for streams that are not on the map help to document the existence of the intermittent stream network. For soil moisture, another qualitative scale (based on the work of Rinderer et al. [2012]) is used.

So far, almost 400 CrowdWater stations have been established, and 121 different participants have made more than 1,000 measurements. Everyone can participate, and all participants in the project can view and request the data. Participants can see a time series of the data collected at each site when they enter new data in the field, and they can use the data to monitor their environment or to plan kayak outings or fishing trips.

The project organizers will also use the data to test their usefulness for hydrologic model calibration and for improving understanding of streamflow dynamics. The long-term goal is to be able to obtain crowdsourced data in countries that have little hydrometric data or to supplement the available data.

Stream Tracker Monitors Intermittent Streams

Stream Tracker focuses on documenting flow patterns in intermittent streams.Stream Tracker focuses on documenting flow patterns in intermittent streams. This project started in April 2017 with funding from the Citizen Science for Earth Systems Program of NASA.

Stream Tracker’s goal is to improve intermittent stream mapping and monitoring using satellite and aircraft remote sensing, in-stream sensors, and crowdsourced observations of streamflow presence and absence. The crowdsourcing component is critical for understanding intermittent streams because remote sensing provides data infrequently, and widespread sensor installation is infeasible. Crowdsourcing can fill in information on streamflow intermittence anywhere people regularly visit streams—during a hike or bike ride or when passing by while commuting.

The Stream Tracker app helps citizen scientists fill in information on intermittent streams in the places they frequent. Credit: Kira Puntenney-Desmond

Stream Tracker sites can be established on any stream through the project website on the citizen science platform CitSci.org. Ideal sites are streams that do not flow continuously, are publicly accessible, and have an evident channel that will be easy to see even when the stream is not flowing. Anyone can join the project, establish sites in locations of interest, and track the streams over time.

Current participants range in age from elementary school students to retired teachers and include not only stream experts but also people who have never monitored streams before. Project members can navigate to the sites using mobile phones or GPS units and can enter data on whether the stream is flowing through the free CitSci.org mobile app.

For researchers who regularly visit field sites, stream tracking is an easy add-on to a field day. Researchers can identify stream crossings on their route to field sites, add these locations as monitoring points on Stream Tracker, and upload data after each field visit. All Stream Tracker data are freely accessible through the project website.

Why Are Crowdsourced Hydrologic Data Useful?

Crowdsourcing projects in hydrology can vastly increase the number of monitored tributaries in a watershed.Crowdsourcing projects in hydrology can vastly increase the number of monitored tributaries in a watershed. For example, over its first year of measurements in the Cache la Poudre basin of northern Colorado, Stream Tracker has revealed which parts of the watershed contributed snowmelt or rainfall runoff to the main river channel at different times of the year, helped improve maps of stream types, and documented habitat conditions for species relying on intermittent streams. As streams change with climate, land use, water use, and other stressors, crowdsourced data can help reveal when, where, and how these changes affect flow.

Crowdsourcing projects can vastly increase the number of monitored tributaries in a watershed and provide information on how climate, land and water use, and other factors affect streamflow. Credit: Kira Puntenney-Desmond

Crowdsourcing hydrologic data is also an easy means to promote public engagement and education about streams and watershed processes. As these and other hydrology-related citizen science projects develop, we will continue to work toward creating accessible tools suited for a wide variety of locations and applications. We welcome any input from others interested in crowdsourcing hydrologic data. You do not need to be a hydrologist to be able to contribute to these projects. It is easy and accessible, and anyone can participate. So get outside and track some streams!

To learn more, share your own streamflow observations, or get involved, visit our websites for CrowdWater and Stream Tracker.

Acknowledgments

CrowdWater is funded by the Swiss National Science Foundation (project 163008). Stream Tracker is funded by NASA award NNX17AF96A. We thank all of the CrowdWater and Stream Tracker participants who have contributed to the networks so far.

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Acoustic Monitoring of Inelastic Compaction in Porous Limestone

Thu, 04/12/2018 - 12:26

An understanding of the short- and long-term evolution of carbonate reservoirs hinges upon a fundamental understanding of inelastic compaction of porous limestone. With the development of 4D seismic monitoring, a better understanding of the in situ evolution of elastic wave velocities of porous carbonates during production or carbon dioxide injection is also clearly needed. A new set of high pressure compression experiments by Baud et al. [2017] revealed that inelastic compaction in Saint Maximin limestone was accompanied by abundant acoustic emission activity, capturing strain localization. Microstructural analysis showed grain crushing was the main mechanism of inelastic compaction in the studied limestone. Microcracking reduced P-wave velocity near the onset of inelastic compaction, while porosity reduction resulted in a significant increase in P-wave velocity.

Citation: Baud, P., Schubnel, A., Heap, M., & Rolland, A. [2017]. Inelastic compaction in high-porosity limestone monitored using acoustic emissions. Journal of Geophysical Research: Solid Earth, 122, 9989–10,008. https://doi.org/10.1002/2017JB014627

—André Revil, Editor, JGR: Solid Earth

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Tree Rings Tell a Tale of Wartime Privations

Wed, 04/11/2018 - 18:03

“Where is Tirpitz?”

Britain’s prime minister Winston Churchill, who was hell-bent on seeing Germany’s largest battle cruiser destroyed, asked the question in 1942 in a memorandum that was notable for its shortness. More than 75 years later, German forest ecologist Claudia Hartl is able to give an answer notable for its method: the growth rings of pines on the Kåfjord in the far north of Norway show that the Tirpitz was anchored there in 1944.

Hartl of the Johannes Gutenberg University in Mainz, Germany, wasn’t looking for an answer to the Tirpitz question when she stumbled upon it. She was investigating instead why something was amiss with some trees she and her students happened to be studying on the Kåfjord. In contrast to the normal-seeming tree rings from other locations in northern Norway, a few cores the researchers took in this area showed no growth ring or a ring that was hardly visible for the year 1945.

Today, at the annual General Assembly of the European Geosciences Union in Vienna, Austria, Hartl discussed new findings that German attempts to hide the massive warship from enemy attacks by means of a chemical fog left enduring evidence in the trees. The previously undiscovered evidence consists of varying amounts of damage to long-lived Scotch pine trees on the lands around Kåfjord. This forensic research is, as far as Hartl knows, the first example of “war dendrochronology.” The team has plans to use additional methods to trace that wartime history in the affected trees.

Silent Sufferers

Hartl and her class discovered that something was wrong with the trees at the Kåfjord after a 2016 excursion to Norway. In subsequent years, they followed up and learned that trees nearer to the fjord had skipped even more years. Some nearest the fjord had even stopped growing for as long as 7 years, returning to normal only after 12 years.

Section of a Scotch pine tree near the Kåfjord, Norway, that was affected by the Tirpitz’s chemical fog in 1944. The tree was far enough from the fjord to undergo a small amount of growth the following year. Each growth ring starts out light, when growth is fast, and ends dark, when denser wood is laid down. The red dotted line indicates the position of the 1945 ring. Credit: Claudia Hartl

Often, such patterns are explained by drought or insect attacks, but the trees that Hartl had analyzed, Scotch pines, are too hardy to stop growing completely in those circumstances. “It is really unusual for Scots pine in Norway to miss a ring,” said Scott St. George, a climate dendrochronologist from the University of Minnesota in Minneapolis who spent a year in Mainz as a Humboldt Fellow and participated in the study. The absent ring indicated that the tree was going all out to survive. “Because it was not forming wood around its circumference, it was taking all of its resources and all of its energy to regrowing a complete crop of needles from top to bottom,” St. George explained.

“Insects don’t affect them to that severity; a cold summer does cause them to form a narrow ring, but to have 60% of all trees not form a ring at all, that’s really odd,” he said. Furthermore, according to Hartl, insect outbreaks that damage trees “have cycles, so you will see missing rings every 7 or 10 years. This is well known for the Alps but not that you have just one single ring, or several, missing over 200 years. That’s really uncommon.”

She and her colleagues wondered if there was something special about the Kåfjord. One day, she asked a Norwegian tree ring specialist, who replied immediately that the Tirpitz was there.

Big Target

The largest battle cruiser ever built for the German Navy, the Tirpitz saw little action, but it was essential in forcing the British navy to deploy resources to prevent it from attacking convoys. While it was stationed in Norway, it was repeatedly attacked by submarines and especially by bomber aircraft. To make the Tirpitz harder to hit, the Germans released chlorosulfuric acid from the ship and from land. Droplets of this compound attract water, forming an impenetrable mist in a matter of minutes. British bomber pilots said that the fog covered the terrain to a height of 600 meters.

Hartl and her research team got their information about the cloaking fog from American military reports. Chlorosulfuric acid is irritating for people, but it was otherwise described as harmless at the time, St. George said, “because cows exposed to it didn’t die immediately.” But for pine trees the effect was severe: Their tree rings show that they lost most of their needles.

Some crewmen of the Tirpitz gather beneath the barrels of one of the ship’s 380-millimeter gun turrets as the ship lies moored in a Norwegian fjord, circa 1942–1944. Several camouflage floats are visible in the distance. Credit: U.S. Naval History and Heritage Command, NH 71388

When St. George and Hartl speak about the trees at the Kåfjord, it is with a certain admiration.

“A tree which shuts down over 9 years, but it’s still alive, imagine this,” Hartl told Eos. “That tree is amazing.”

Regarding this new study, “I found it pretty cool,” said Georg von Arx, a tree ring expert at the Swiss Federal Institute for Forest, Snow and Landscape Research in Birmensdorf. “It was very original research, and it shows what a huge diversity of questions we can tackle with tree rings. And scientifically, it was very well done.”

Von Arx agrees that the missing rings are a sign that the trees had lost their needles. And he offers advice: “I think if she has the chance she should go back and sample them a bit higher up. I would expect to see fewer missing rings as you move upwards in the stem.” This is because a growth ring consists of many rings of sapwood, which transports water. “In the sapwood at breast height you still have alternative pathways for the water, but as you move towards the tips of the branches, there are fewer and fewer sapwood rings, eventually only one. And a new needle needs to be connected to a new level of cells: either there is a sapwood ring there, or there can be no needle growth. This difference with height would show that the tree was rebuilding the canopy before—and this is always second priority—growing the stem.”

Learning More

It’s possible that the acid fog has left not only physical traces in the tree but also chemical ones inside the wood.The Tirpitz was eventually sunk in November 1944, but its legacy remains in the trees, which Hartl said can survive 400–500 years. It’s possible that the acid fog has left not only physical traces in the tree but also chemical ones inside the wood. The team is now looking for evidence of that, analyzing their samples with a mass spectrometer.

Finding out as much as possible is important, according to Hartl, because until now nothing was known about the environmental consequences of battles involving the Tirpitz, and the same goes for many other engagements in wartime. “The Kåfjord was not the only place where the German navy used the smoke. They used it to obscure other ports and other cities. There may be fingerprints in other places that people haven’t paid attention to,” said St. George.

In some sense, the Scotch pines of Norway are also monuments, he added. “We’re losing the generation that remembers the Second World War. It’s easier to forget the lessons after that event. In this case, the trees still keep that evidence alive. Even if you didn’t know anything about the history of the Kåfjord, or the Tirpitz, the information is still preserved, when you have the right person to read it.”

—Bas den Hond (email: bas@stellarstories.com), Freelance Journalist

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James Reilly to Take the Helm at USGS

Wed, 04/11/2018 - 18:02

The U.S. Senate has confirmed a former astronaut and petroleum geologist as the next director of the U.S. Geological Survey (USGS). The Senate approved James F. Reilly by a voice vote on Monday to be the director, taking over from William Werkheiser, who has served as acting director since 2017.

Reilly testified at his 6 March confirmation hearing that the agency’s budget and its scientific integrity would be among his top priorities. “I am fully committed to scientific integrity,” he said at that hearing. Reilly, who flew on three NASA space shuttle missions and holds a Ph.D. in geosciences from the University of Texas at Dallas, explained that he would emphasize scientific integrity in his new role because USGS “is an independent organization that is designed to deliver unbiased science to the decision makers.”

Arriving After a Budget Scare

Reilly joins the agency at a time when it has just received a reprieve from potential budget cuts.He joins the agency at a time when it has just received a reprieve from potential budget cuts. The omnibus spending bill that U.S. President Donald Trump reluctantly signed into law on 23 March reversed the administration’s plans to sharply reduce funding of federal science agencies, including USGS. The spending bill provides USGS with $1.15 billion for fiscal year (FY) 2018, compared with $1.09 billion appropriated by the FY 2017 omnibus bill and $922 million in the administration’s proposed FY 2018 budget.

Reilly takes charge also not long after an incident raised some questions about the ethics at the agency. A few months ago, former USGS associate director for energy and minerals Murray Hitzman resigned out of concern that USGS provided final results of an assessment of the National Petroleum Reserve in Alaska to the U.S. secretary of the interior before its public release, although the Interior Department said the secretary acted within his authority. USGS is within the Department of the Interior.

Former Directors Weigh In

U.S. National Academy of Sciences president Marcia McNutt, who served as the USGS director from 2009 to 2013 during the Obama administration, told Eos that Reilly won’t have to micromanage the agency because “the staff are really great and the agency really runs itself” but that he will have a very full portfolio.

McNutt, who from 2000 to 2002 was president of the American Geophysical Union, publisher of Eos, said that she worked hard as USGS’s only political appointee and its liaison to the political infrastructure at Interior and the White House. She noted also expending great effort developing relationships with congressional appropriators on both sides of the political aisle and occasionally shielding her staff from “perhaps well intentioned, but scientifically or ethically unacceptable, requests from political appointees who had not thought through the implications of their requests.”

Add to that the demands of disasters. “I was the front for the agency on a number of disasters,” McNutt recalled. Today, “with the accelerated pace of changing climate, the USGS role in responding to drought, flood, fires, storm surge, landslides, and other disasters could increase in pace. The new director will need to do all of these things.”

Charles G. “Chip” Groat, who led USGS from 1998 to 2005, told Eos that Reilly has a “commendable” professional record and “having been an astronaut gives him an aura of sorts.” However, he expressed concern about how much Reilly will be “expected to hew [to] the Trump and Zinke lines on government agencies and services.” Besides taking aim at the USGS budget, the Trump administration “has moved some of the climate change leaders into other areas,” Groat noted.

Although the director of USGS is a presidential appointment, that so far “hasn’t resulted in directors who were perceived by the science community as ‘political,’” Groat said. “I hope Dr. Reilly will continue in that mode.”

Reilly’s number one responsibility will be “to protect the quality of the science and the objectivity of the organization.”Mark Myers, who served as USGS director from 2006 through 8 January 2009, during the George W. Bush administration, said that Reilly’s number one responsibility will be “to protect the quality of the science and the objectivity of the organization.”

“It is a more politically charged environment than I was in. So that’s going to be a big challenge for him, and he’s going to have to figure out how to deal with it,” Myers said. “You try to look at the science objectively, but you have to be able to convey that in a politically charged environment.”

Other challenges for Reilly include making sure that the organization maintains an adequate budget and its interdisciplinary nature and getting well acquainted with both how the agency is organized and its people, he added. Myers said he would want Reilly to know that “you’ve got an incredibly brilliant group of scientists you work with” at USGS.

Reilly’s Initial Outlook

Reilly told Eos after his confirmation hearing last month that what most excites him about the position is “working with [thousands of] professionals who love the job as much as I will.” Asked why he thinks the administration chose him for the position, he responded, “Good question. I don’t know, but I’m damn glad they did.”

—Randy Showstack (@RandyShowstack), Staff Writer

Correction, 13 April 2018: This article has been revised to more accurately reflect comments by Marcia McNutt.

Update, 13 April 2018: After this article published, James Reilly, the new director of USGS, provided Eos with a comment about his Senate confirmation. He told Eos, “I’m honored to be confirmed by the Senate as the 17th Director of the USGS. I truly appreciate the trust shown in my nomination by Secretary Zinke and President Trump and look forward to an exciting term of office working closely with the dedicated scientists and staff of the Bureau. This is a great honor and I’m really looking forward to getting down to work as soon as possible.”

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Melting of Arctic Mountain Glaciers Unprecedented in the Past 400 Years

Wed, 04/11/2018 - 11:47

Glaciers in Alaska’s Denali National Park are melting faster than at any time in the past four centuries because of rising summer temperatures, a new study finds.

New ice cores taken from the summit of Mt. Hunter in Denali National Park show summers there are least 1.2–2 degrees Celsius (2.2–3.6 degrees Fahrenheit) warmer than summers were during the 18th, 19th, and early 20th centuries. The warming at Mt. Hunter is about double the amount of warming that has occurred during the summer at areas at sea level in Alaska over the same time period, according to the new research.

The warmer temperatures are melting 60 times more snow from Mt. Hunter today than the amount of snow that melted during the summer before the start of the industrial period 150 years ago, according to the study. More snow now melts on Mt. Hunter than at any time in the past 400 years, said Dominic Winski, a glaciologist at Dartmouth College in Hanover, New Hampshire and lead author of the new study published in the Journal of Geophysical Research: Atmospheres, a journal of the American Geophysical Union.

The new study’s results show the Alaska Range has been warming rapidly for at least a century. The Alaska Range is an arc of mountains in southern Alaska home to Denali, North America’s highest peak.

The warming correlates with hotter temperatures in the tropical Pacific Ocean, according to the study’s authors. Previous research has shown the tropical Pacific has warmed over the past century due to increased greenhouse gas emissions.

The study’s authors conclude warming of the tropical Pacific Ocean has contributed to the unprecedented melting of Mt. Hunter’s glaciers by altering how air moves from the tropics to the poles. They suspect melting of mountain glaciers may accelerate faster than melting of sea level glaciers as the Arctic continues to warm.

Understanding how mountain glaciers are responding to climate change is important because they provide fresh water to many heavily-populated areas of the globe and can contribute to sea level rise, Winski said.

“The natural climate system has changed since the onset of the anthropogenic era,” he said. “In the North Pacific, this means temperature and precipitation patterns are different today than they were during the preindustrial period.”

Assembling a Long-Term Temperature Record Researchers drill an ice core at their camp on the summit plateau of Mt. Hunter. Credit: Dominic Winski.

Winski and 11 other researchers from Dartmouth College, the University of Maine and the University of New Hampshire drilled ice cores from Mt. Hunter in June 2013. They wanted to better understand how the climate of the Alaska Range has changed over the past several hundred years, because few weather station records of past climate in mountainous areas go back further than 1950.

The research team drilled two ice cores from a glacier on Mt. Hunter’s summit plateau, 13,000 feet above sea level. The ice cores captured climate conditions on the mountain going back to the mid-17th century.

The physical properties of the ice showed the researchers what the mountain’s past climate was like. Bands of darker ice with no bubbles indicated times when snow on the glacier had melted in past summers before re-freezing.

Winski and his team counted all the dark bands–the melt layers–from each ice core and used each melt layer’s position in the core to determine when each melt event occurred. The more melt events they observed in a given year, the warmer the summer.

They found melt events occur 57 times more frequently today than they did 150 years ago. In fact, they counted only four years with melt events prior to 1850. They also found the total amount of annual meltwater in the cores has increased 60-fold over the past 150 years.

The surge in melt events corresponds to a summer temperature increase of at least 1.2-2 degrees Celsius (2.2–3.6 degrees Fahrenheit) relative to the warmest periods of the 18th and 19th centuries, with nearly all of the increase occurring in the last 100 years. Because there were so few melt events before the start of the 20th century, the temperature change over the past few centuries could be even higher, Winski said.

Connecting the Arctic to the Tropics One of the ice cores taken from Mt. Hunter in June 2013. The bands of dark ice represent times when glacier snow melted and refroze in past summers. Credit: Dominic Winski.

The research team compared the temperature changes at Mt. Hunter with those from lower elevations in Alaska and in the Pacific Ocean. Glaciers on Mt. Hunter are easily influenced by temperature variations in the tropical Pacific Ocean because there are no large mountains to the south to block incoming winds from the coast, according to the researchers.

They found during years with more melt events on Mt. Hunter, tropical Pacific temperatures were higher. The researchers suspect warmer temperatures in the tropical Pacific Ocean amplify warming at high elevations in the Arctic by changing air circulation patterns. Warmer tropics lead to higher atmospheric pressures and more sunny days over the Alaska Range, which contribute to more glacial melting in the summer, Winski said.

“This adds to the growing body of research showing that changes in the tropical Pacific can manifest in changes across the globe,” said Luke Trusel, a glaciologist at Rowan University in Glassboro, New Jersey who was not connected to the study. “It’s adding to the growing picture that what we’re seeing today is unusual.”

The post Melting of Arctic Mountain Glaciers Unprecedented in the Past 400 Years appeared first on Eos.

Scientists Discover New Ocean Current off Madagascar

Wed, 04/11/2018 - 11:47

While investigating coastal upwelling that nourishes marine wildlife and fisheries off the coast of Madagascar, Ramanantsoa et al. identified a previously unrecognized current. The Southwest Madagascar Coastal Current (SMACC) is a rare example of a subtropical surface current flowing in a poleward direction off the western coast of a continent or a large island—in this case, Madagascar.

Previous studies have provided a general picture of currents near Madagascar: The Indian Ocean’s South Equatorial Current, which flows east to west, splits in two at the east coast of the island. The resulting North Madagascar Current flows toward the northern tip of the island, while the East Madagascar Current flows along the island’s eastern coast to its southern tip. However, finer details of ocean circulation around Madagascar have remained unclear.

To better characterize ocean dynamics in the region, the researchers investigated upwelling off Madagascar’s southern coast. They analyzed shipboard observations of water speed, direction, salinity, depth, temperature, and more. They also evaluated satellite observations of sea surface temperature, data on temperature and salinity from free-floating Argo instruments, and a computational model of ocean dynamics in the area.

The analysis revealed that much of the water involved in upwelling in the region is not transported by the East Madagascar Current as previously thought. Instead, it comes from the western side of the island, traveling down the southwest coast of Madagascar. This discovery suggests the presence of a previously unknown, warm surface current: SMACC.

According to the observational and computer modeling data, SMACC’s average length is about 500 kilometers, and its average width ranges between 50 and 100 kilometers. It extends from the surface to a depth of about 150 meters upstream and about 70 meters downstream.

Driven by winds, SMACC flows faster in warmer seasons, but its average speed is 20 centimeters per second. It transports an average of about 1.3 million cubic meters of water per second, almost comparable to the Leeuwin Current, a similarly rare poleward-flowing warm current off Australia’s western coast.

Because SMACC plays a central role in the ocean upwelling system, which “fertilizes” coastal marine life with nutrient-rich waters, its identification could help improve ecosystem and fisheries management in the region. With further research, it could also help explain other ocean features recently observed in the region. (Geophysical Research Letters, https://doi.org/10.1002/2017GL075900, 2018)

—Sarah Stanley, Freelance Writer

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