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New model indicates 320 million trees are killed by lightning each year—considerable biomass loss

Phys.org: Earth science - Tue, 07/22/2025 - 11:30
Lightning has a greater impact on forests than previously thought. Researchers at the Technical University of Munich (TUM) have developed new model calculations that, for the first time, estimate the global influence of lightning on forest ecosystems.

Overlooked climate-change danger: Wildfire smoke

Phys.org: Earth science - Tue, 07/22/2025 - 11:30
Loretta Mickley first started thinking about smoke in the summer of 2002.

Naval Postgraduate School launches sustainable buoy to advance research

Phys.org: Earth science - Tue, 07/22/2025 - 11:10
Located about 3 miles offshore and 5 miles north of the Naval Postgraduate School is a first-of-its-kind ocean-sensing buoy. With 5G technologies and solar panels built in, the buoy has the capabilities to collect oceanographic and meteorological data 24 hours a day, seven days a week for the next three years.

Seismic imaging of pure quasi-P-wave in the VTI media by using the optical flow to calculate phase-velocity direction

Geophysical Journal International - Tue, 07/22/2025 - 00:00
SummaryIncorporating anisotropy in seismic imaging is important to produce correct locations and amplitudes of subsurface reflectors. The pure quasi-P-wave equation has a good accuracy to describe wave propagation in the anisotropic media, but it requires complicated computation strategies. To mitigate this issue, we present a novel pure quasi-P-wave equation in the vertical transverse isotropic (VTI) media with a nonlinear scalar operator, which is determined by the anisotropic parameters and the phase-velocity vector. Inaccurately calculating the directions of wave propagation results in incorrect phase-velocity vector and accumulated simulation error. Here, we utilize the optical flow to accurately calculate the direction of wave propagation while maintaining computational efficiency. Then, we optimize the wavefield simulation workflow and accelerate the calculation of optical flow. Numerical experiments show that the proposed wavefield simulation method can accurately describe wave propagation in the VTI media with good computational efficiency. Finally, we apply the proposed method to reverse-time migration to correct the anisotropic effects in seismic imaging. Numerical tests for benchmark models and a land survey demonstrate the feasibility and adaptability of the proposed method.

Seismic study reveals hidden megathrust earthquake risk off British Columbia

Phys.org: Earth science - Mon, 07/21/2025 - 14:30
A new study published in Science Advances has revealed the first detailed images of a newly developing subduction zone off the coast of British Columbia's Haida Gwaii archipelago.

New map reveals 332 Antarctic submarine canyons, five times more than before

Phys.org: Earth science - Mon, 07/21/2025 - 14:20
Submarine canyons are among the most spectacular and fascinating geological formations to be found on our ocean floors, but at an international level, scientists have yet to uncover many of their secrets, especially those located in remote regions of Earth like the North and South Poles.

Ocean nutrient ratios shift, challenging the long-standing Redfield Ratio model

Phys.org: Earth science - Mon, 07/21/2025 - 13:50
A new study published in Nature Geoscience has revealed that the global ocean's chemical makeup is undergoing a transformation, with key nutrient ratios critical to marine life shifting away from the long-accepted Redfield Ratio over the past decades.

Curved fault slip captured on CCTV during Myanmar earthquake

Phys.org: Earth science - Mon, 07/21/2025 - 13:40
Dramatic CCTV video of fault slip during a large earthquake in Myanmar thrilled both scientists and casual observers when it was posted to YouTube. But it was on his fifth or sixth viewing, said geophysicist Jesse Kearse, that he spotted something even more exciting.

Living with climate change: How to adapt to rising sea levels and changing rainfall patterns at the North Sea coast

Phys.org: Earth science - Mon, 07/21/2025 - 13:13
The trek across the North Sea island of Norderney—a barrier island in the German North Sea—is around five kilometers long. Designed by Lena Thissen, a researcher from the University of Oldenburg, Germany, together with a social scientist from the University of Hamburg, the "Freshwater Lens Walk" is all about a hidden treasure: the island's freshwater supply.

New Research Shows More Extreme Global Warming Impacts Looming for the Northeast

EOS - Mon, 07/21/2025 - 12:00

This article originally appeared on Inside Climate News, a nonprofit, non-partisan news organization that covers climate, energy, and the environment. Sign up for its newsletter here.

A pair of new climate studies suggest an intensification of strong storms called nor’easters and other disruptive extremes affecting the East Coast of North America on an overheated planet.

Nor’easters generally form within about 100 miles of the East Coast between North Carolina and Massachusetts, often when cooler air from Canada meets warm, moist air over Gulf Stream waters. Those contrasting air masses can start to spin with a nudge from the jet stream, fueling storms that can produce damaging winds, coastal flooding and intense, disruptive snowfall in the winter.

The strongest nor’easters are already significantly windier and rainer than they were in the middle of the 20th century, said University of Pennsylvania climate scientist Michael Mann, a coauthor of a study published on 14 July in the Proceedings of the National Academy of Sciences.

A 2022 study showed a similar trend of intensification for storms forming over the Atlantic and hitting Europe, and that the track of those storms is moving northward, potentially putting unsuspecting areas more at risk.

Mann said the increases in the intensity and precipitation rates of the strongest nor’easters have likely been fueled by increases in ocean temperatures and the increased moisture capacity of a warming atmosphere.

“There are two reasons to look at the most intense nor’easters,” Mann said via email. “First, from an impact standpoint, they do the most damage, including coastal erosion, destruction and paralyzing snowfalls. The 1962 Ash Wednesday storm, with 84 mile per hour gusts, is a great example. In today’s dollars, it did $21 billion worth of damage.”

And just last February, a classic nor’easter described at the time as a “bomb cyclone” dropped several feet of snow over parts of Virginia and North Carolina and caused damaging flooding along parts of the Massachusetts coast, Eastern Long Island, and the Jersey Shore.

Mann said the increases in the intensity and precipitation rates of the strongest nor’easters have likely been fueled by increases in ocean temperatures and the increased moisture capacity of a warming atmosphere.

The researchers tracked 900 nor’easters back to 1940 in combination with a careful reanalysis of historical climate conditions surrounding the storms, including notable events like the Perfect Storm in 1991, Storm of the Century in 1993, and Snowmaggedon in 2010.

In the very strongest storms, the wind speeds have increased about 5.4%, from 69 to 71 mph, “but since destructive potential goes as the wind speed cubed, that’s a roughly 17% increase in destructive potential,” Mann said.

Overall, he added, a lot of research suggests that extra warming in the Arctic, which reduces the temperature contrast between high latitudes and midlatitudes, will lead to less storminess overall, but the destructive potential of intensifying nor’easters warrants attention.

Compared to other types of storms, nor’easters feed more off the heat of the ocean, which remains considerable in winter, “So those storms that can make it past the obstacles to development have the potential to grow stronger than they otherwise would have,” he said. “While we don’t see any evidence of increased intensity for the ‘average’ nor’easter, the strongest ones are clearly getting stronger.”

“My interest in these storms, and how they’re being impacted by climate change has been inspired by two personal experiences,” he said, first noting the March 1993 “storm of the century,” which caused 270 deaths and $12.2 billion worth of damage across 26 states, according to the National Ocean and Atmospheric Administration.

Mann said the storm disrupted a spring break road trip in Florida, where the temperature in St. Augustine dropped from the 70s to 40s in a few hours.

“We drove past Okefenokee Swamp later that day and it was snowing,” Mann said. “Then we stopped off in Southern Georgia for the night and temperatures dropped to the mid 20s. We froze. I will never forget that.”

“The strongest nor’easters can have impacts comparable to category 1 and 2 hurricanes, with effects encompassing a larger area.”

He said he remembers another infamous nor’easter, Snowmaggedon, from February 2010 because a U.S. senator who rejects science that proves human-caused warming used the occasion to build what he called an igloo in an attempt to cast doubt on climate science. At the same time, Mann said he ended up stuck in a hotel room for three days with several feet of snow blocking most roads in Pennsylvania.

As such storms grow stronger in a warming world, said Anthony Broccoli, an atmospheric scientist at Rutgers University who was not involved in the new study but who also researches nor’easters, “it will be important to remember that the strongest nor’easters can have impacts comparable to category 1 and 2 hurricanes, with effects encompassing a larger area.”

With sea level rise accelerating along the East Coast, Broccoli added that nor’easters “will lead to greater coastal flooding even without any changes in storm intensity.”

The increased thermal energy from warming oceans is likely driving the trend toward stronger nor’easters, and there could be other large-scale changes to ocean currents and winds that could shift the tracks of nor’easters, potentially raising unexpected risks in new areas, he said.

The new research doesn’t mean that temperatures are getting colder, but that the frigid air that still does form over the Arctic in winter will still make its way south, showing up perhaps more frequently in unexpected regions, or with increased unusual seasonal extremes that can damage crops.

The Arctic Connection

Large-scale changes affecting nor’easters and cold weather extremes in the United States likely include accelerated warming of the Arctic region, climatologist Judah Cohen said in an email interview. Cohen, a visiting scientist at MIT and director of seasonal research with Atmospheric and Environmental Research, published an 11 July study in Science Advances that bolsters evidence for a climate connection.

Cohen said that, as far as he’s concerned, the new paper is “preaching to the choir,” because its conclusions are consistent with his own research showing that “Arctic change can lead to episodic increases in severe winter weather in the U.S. east of the Rockies including extreme cold and disruptive snowfalls.”

The temperature contrast between the Arctic and the midlatitudes is one of the main forces that creates key winds at different altitudes, like the jet stream and polar vortex, and moves weather systems around the Northern Hemisphere.

Cohen’s work over recent years suggests that accelerated warming of the Arctic “stretches” the polar vortex—like elongating a round rubber band—into positions that let cold polar air spill southward more frequently.

He noted that two of the most recent nor’easters specifically named in the new paper by Mann and his coauthors, in March 1993 and January 2018, occurred during stretched polar vortex events. The new paper, he said, “provides a medley of possible causes but doesn’t settle on any one cause.”

His own recent paper, he said, shows “for the first time that stretched polar vortex events are overwhelmingly associated with extreme cold and heavy snowfall in the Eastern U.S.,” compared to other polar vortex configurations.

Often the polar vortex flows in a tight coil around the North Pole, containing the Arctic air, but Cohen’s study, and other research, suggest a trend to more frequent stretched polar vortexes and the associated cold-air outbreaks and storm impacts. Taken altogether, he said the new research helps explain regional “winter cooling trends and an increased number of heavy snowfalls in the Eastern U.S. over the past two and a half decades.”

—Bob Berwyn (@bberwyn), Inside Climate News

Nonlinear kinetic simulations of Jeans instability in a magnetized dusty plasma

Physical Review E (Plasma physics) - Mon, 07/21/2025 - 10:00

Author(s): Masaru Nakanotani, Luis Lazcano Torres, Gary P. Zank, and Edward Thomas, Jr.

The Jeans instability in a magnetized dusty plasma is considered a fundamental process in space, where magnetic fields are common. We investigate the Jeans instability in a magnetized dusty plasma using 1D and 2D particle-in-cell simulations, in which dust grains are treated as particles and the Poi…


[Phys. Rev. E 112, 015208] Published Mon Jul 21, 2025

Spontaneous Potential Surveys in Surface Fresh Waters for Engineering and Environmental Applications

Geophysical Journal International - Mon, 07/21/2025 - 00:00
AbstractGeophysicists using the spontaneous potential method measure differences in electrical potential without providing an active source of current. Most spontaneous potential surveys have been carried out on land or in marine environments. In the present paper, I evaluate the use of the spontaneous potential method in surface fresh water for small-scale environmental and engineering applications. In one survey reported here, the electrical potential between an electrode at the river edge and one suspended from a bridge was used to measure a high resolution profile across a river. In another, electrical potentials were measured between sets of electrodes mounted on a canoe. In both surveys, significant and consistent anomalies were detected particularly near bridge structures, and simple modeling in terms of point sources and line sources was undertaken to better characterize the causes of the anomalies. The possibility of an induction-induced voltage difference across the river caused by Earth’s magnetic field and flow in the river was also investigated. The absence of this potential is attributed to significant electrical conduction through the riverbed. The present work demonstrates the utility of spontaneous potential as a technique for detecting and characterizing anomalies of environmental and engineering interest in fresh water environments.

Modeling P wave reflections on MTZ discontinuities from distant oceanic sources

Geophysical Journal International - Mon, 07/21/2025 - 00:00
AbstractWe investigate the modeling of P-wave reflections on the mantle transition zone (MTZ) discontinuities (Pv410p* and Pv660p*) using ambient seismic noise generated by distant oceanic sources. Using ray theory and waveform simulations, we assess biases in arrival times and amplitude ratios when interpreting noise correlations as Green‘s functions. Our results show that source distribution and the b-caustic effect strongly influence signal recovery. Simulations based on realistic oceanic models (WAVEWATCH III) demonstrate that appropriate source conditions significantly reduce biases. This approach enables reliable imaging of the MTZ, particularly in regions like the greater Alpine area with favorable microseismic source distribution.

Accurate Detection of Hidden Faults in Xianlin Area, Nanjing (China) Based on a Dense, Short-Period Seismic Array

Geophysical Journal International - Mon, 07/21/2025 - 00:00
SummaryHigh-resolution detection of hidden geological faults is vital for city planning, earthquake disaster prevention, and large-scale engineering construction. This study deployed 229 short-period seismometers across a 10×30 km region within the Xianlin area of Nanjing. Of which, 199 formed a 2-D array, and 30 formed a linear array. Various methods were applied to detect hidden faults in the study area. Using ambient noise tomography, a three-dimensional (3D) S-wave velocity structure was obtained from the surface to a depth of 6.0 km, allowing the first locations of a hidden fault to be mapped via velocity anomalies. A linear array was subsequently deployed based on these early findings, and the horizontal-to-vertical spectral ratio (HVSR) method was applied to estimate bedrock depth and define shallow fault features in greater detail. Finally, a shallow seismic exploration was performed to verify the detection results of ambient noise tomography and HVSR analysis. The results indicate the presence of a hidden fault in the study area, which manifests as a distinctive area of alteration in the high- and low-velocity anomalies in the 3D S-wave velocity structure. Significant variation was identified in the sediment layer thickness in the shallow subsurface, as observed in the HVSR records. In addition, shallow seismic exploration defined important wave-group phase-axis discontinuities in areas with abrupt sedimentary thickness changes. Thus, the hidden fault identified in this study is a normal fault with a nearly north-dipping direction, dip angle of approximately 60°, and fault displacement of approximately 30 m. By linking these results with previous data, it is possible to suggest that such hidden faults are part of the Mufushan–Jiaoshan Fault. Future urban designs and buildings must thoroughly consider the seismic dangers in this region and apply suitable mitigation strategies.

Joint Reprocessing Method of Multi-Vintage Shipborne Gravity Anomalies Considering Temporal Error Effects: A Case Study of the Philippine Sea

Geophysical Journal International - Mon, 07/21/2025 - 00:00
SummaryShipborne gravity anomaly data exhibit multi-vintage characteristics due to their extended temporal coverage. Currently, the measurement accuracy of gravimeters and the processing methods for shipborne gravity anomaly data have been significantly improved and refined. At this stage, the influence of temporal error on the processing of shipborne gravity anomaly data has become an issue that cannot be neglected. We propose a joint reprocessing method for multi-vintage shipborne gravity anomaly data considering temporal error effects. Firstly, the gross error of the shipborne gravity anomaly data is eliminated and filtered. When compensating for the survey line error, the time variable is added to the error equation in order to retain the temporal information in the observed value. The corrected shipborne gravity anomaly data by this method is closer to the real gravity field information. We applied this method to the real shipborne gravity anomaly data in the Philippine Sea. The results showed that the standard deviation of the discrepancy at the intersection points of the survey lines was reduced from the initial 13.46 mGal to 4.30 mGal. The shipborne gravity anomaly data processed after considering the temporal error effects conforms more closely to the actual gravity field information.

We detected deep pulses beneath Africa—what we learned could help us understand volcanic activity

Phys.org: Earth science - Sun, 07/20/2025 - 14:50
Earth's continents may look fixed on a globe, but they've been drifting, splitting and reforming over billions of years—and they still are. Our new study reveals fresh evidence of rhythmic pulses of molten rock rising beneath east Africa, reshaping our understanding of how continents break apart.

Restoring sea floor after mining may not be possible, researchers warn

Phys.org: Earth science - Sun, 07/20/2025 - 13:59
Scientists present at the latest effort to hash out international rules for deep-sea mining say it's unclear if it's possible to restore damaged seafloor ecosystems—or how long it would take.

Dead Sea's salt giants reveal how massive salt deposits form over time

Phys.org: Earth science - Sat, 07/19/2025 - 11:40
The Dead Sea is a confluence of extraordinary conditions: the lowest point on Earth's land surface, with one of the world's highest salinities. The high concentration of salt gives it a correspondingly high density, and the water body's status as the deepest hypersaline lake gives rise to interesting and often temperature-related phenomena below the water's surface that researchers are still uncovering.

Machine learning uncovers 10 times more earthquakes in Yellowstone caldera

Phys.org: Earth science - Sat, 07/19/2025 - 11:31
Yellowstone, a popular tourist destination and namesake of an equally popular TV show, was the first-ever national park in the United States. And bubbling beneath it—to this day—is one of Earth's most seismically active networks of volcanic activity.

Myanmar earthquake's fault rupture exceeded seismic wave speeds, offering rare evidence of supershear

Phys.org: Earth science - Sat, 07/19/2025 - 11:27
The first studies of the 28 March 2025 magnitude 7.8 Myanmar earthquake suggest that the southern portion of its rupture occurred at supershear velocity, reaching speeds of 5 to 6 kilometers per second.

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