Phys.org: Earth science

Stanford researchers have created the first-ever global map of a rare earthquake type that occurs not in Earth's crust but in our planet's mantle, the layer sandwiched between the thin crust and Earth's molten core. The new map will help scientists learn more about the mechanics of mantle earthquakes, in turn opening a window into the complexities and triggers for all earthquakes.

A combination of weakened atmospheric removal and increased emissions from warming wetlands, rivers, lakes, and agricultural land increased atmospheric methane at an unprecedented rate in the early 2020s, an international team of researchers report today in the journal Science.

In the Pacific Northwest, big faults like the Cascadian subduction zone located offshore, get a lot of attention. But big faults aren't the only ones that pose significant hazards, and a new study investigates the dynamics of a complex fault zone that runs right under the heart of Seattle.

Scientists at the University of Southampton have uncovered evidence from ancient rocks that Earth's climate continued to fluctuate during its most extreme ice age—known as Snowball Earth. During the Cryogenian Period, between 720 and 635 million years ago, it has long been believed that Earth's climate entirely shut down.

Every year at Grand Canyon National Park, millions of visitors from all over the world stop at one of a dozen water spigots. Most people are on a rim, seeing the canyon's majesty for the first time, when they step off the trail to refill a water bottle. Others are deep in the belly of the canyon, sweaty and tired, facing a hike up in punishing heat, filling their reservoirs and dumping water over their heads to avoid dehydration and heat stroke.

Global climate models capture many of the processes that shape Earth's weather and climate. Based on physics, chemistry, fluid motion and observed data, hundreds of these models agree that more carbon dioxide in the atmosphere leads to hotter global temperatures and more extreme weather. Still, uncertainty remains around how seasonal weather patterns and atmospheric systems like the jet stream will respond to global warming. Some of this uncertainty stems from the way models approximate the effects of relatively short-lived, small-scale phenomena known as gravity waves.

Seamounts and the oxygen minimum zone (OMZ) are two typical deep-sea habitats that often coexist. However, determining whether the "seamount effect" alters OMZ structure through marine stratification, thereby influencing the deep-sea hypoxic environment and carbon sink processes, remains unconfirmed.

British scientists said Thursday that a world-first AI tool to catalog and track icebergs as they break apart into smaller chunks could fill a "major blind spot" in predicting climate change.

Great things can come from failure when it comes to geology. The Midcontinent rift formed about 1.1 billion years ago and runs smack in the middle of the United States at the Great Lakes. The rift failed to completely rupture, and had it succeeded it would have torn North America apart. Under immense pressure from receding tectonic plates, the weakened lithosphere instead created a basin in the crust eventually filled by Lake Superior, and it also exposed a 3000-km-long band of deeply buried igneous and sedimentary rocks.

Forest soils have an important role in protecting our climate: They remove large quantities of methane—a powerful greenhouse gas—from our atmosphere. Researchers from the University of Göttingen and the Baden-Württemberg Forest Research Institute (FVA) have evaluated the world's most comprehensive data set on methane uptake by forest soils. They discovered that under certain climate conditions, which may become more common in the future, forest soils' capacity to absorb methane actually increases.

The Asian-Australian monsoon system (A-AuMS) is the world's most typical cross-equatorial coupled monsoon system. On a seasonal timescale, the summer monsoon in one hemisphere is usually linked to the winter monsoon in the other via outflows. However, robust evidence is lacking as to whether such cross-equatorial monsoon coupling persists during orbital-scale paleoclimate evolution. A scarcity of high-resolution paleoclimatic records from the Northern Australian monsoon region in the Southern Hemisphere has limited a full understanding of the A-AuMS's dynamic mechanisms.

Parts of ancient Earth may have formed continents and recycled crust through subduction far earlier than previously thought. New research led by scientists at the University of Wisconsin–Madison has uncovered chemical signatures in zircons, the planet's oldest minerals, that are consistent with subduction and extensive continental crust during the Hadean Eon, more than 4 billion years ago.

Chemicals brought in to help protect our ozone layer have had the unintended consequences of spreading vast quantities of a potentially toxic "forever chemical" around the globe, a new study shows. Atmospheric scientists, led by researchers at Lancaster University, have for the first time calculated that CFC replacement chemicals and anesthetics are behind around a third of a million metric tons (335,500) of a persistent forever chemical called trifluoroacetic acid (TFA) being deposited from the atmosphere across Earth's surface between the years 2000 and 2022.

When snow blankets the landscape, it may seem like life slows down. But beneath the surface, an entire world of activity is unfolding.

A swarm of small earthquakes within the Karoo Basin in South Africa has revealed a critically stressed fault that could be perturbed by potential shale gas exploration in the area, according to a new report. The analysis by Benjamin Whitehead of the University of Cape Town and colleagues concludes that the Karoo microseismicity occurred along a buried fault that may extend through sedimentary layers to the crystalline bedrock, which would increase its vulnerability to stresses produced by shale gas exploration.

An international research team led by the University of Bremen has detected chlorofluorocarbons (CFCs) in Earth's atmosphere for the first time in historical measurements from 1951—20 years earlier than previously known. This surprising glimpse into the past was made possible by analyzing historical measurement data from the Jungfraujoch research station in the Swiss Alps. The study has now been published in Geophysical Research Letters.

Mantle plumes beneath volcanic hotspots, like Hawaii, Iceland, and the Galapagos, seem to be anchored into a large structure within the core-mantle boundary (CMB). A new study, published in Science Advances, takes a deeper dive into the structure under Hawaii using P- and S-wave analysis and mineralogical modeling, revealing its composition and properties.

Scientists at the University of California, Irvine have discovered that climate change is causing nitrous oxide, a potent greenhouse gas and ozone-depleting substance, to break down in the atmosphere more quickly than previously thought, introducing significant uncertainty into climate projections for the rest of the 21st century.

Arctic sea ice has large effects on the global climate. By cooling the planet, Arctic ice impacts ocean circulation, atmospheric patterns, and extreme weather conditions, even outside the Arctic region. However, climate change has led to its rapid decline, and being able to make real-time predictions of sea ice extent (SIE)—the area of water with a minimum concentration of sea ice—has become crucial for monitoring sea ice health.

A pair of US researchers have developed a new model to tackle a deceptively simple problem: how a small block of ice melts while floating in calm water. Using an advanced experimental setup, Daisuke Noto and Hugo Ulloa at the University of Pennsylvania have captured the intricate dynamics that underlie this everyday process—work that could ultimately pave the way for more accurate predictions of melting sea ice. The study has been published in Science Advances.