Phys.org: Earth science

The southern Indian Ocean off the west coast of Australia is becoming less salty at an astonishing rate, largely due to climate change, new research shows.

A new study shows that during the last two deglaciations, i.e., the transition from an ice age to the warm interglacial periods, meltwater from the Antarctic ice sheet intensified stratification in the Southern Ocean. The results highlight the key role of the Antarctic ice sheet on ocean circulation and the regulation of the global climate. The study was led by François Fripiat, a researcher at the Max Planck Institute for Chemistry and the Université Libre de Bruxelles, and was conducted in collaboration with researchers from Princeton University and the Alfred Wegener Institute. It is published in the Proceedings of the National Academy of Sciences.

The Arctic is warming faster than the rest of the planet, with average temperatures increasing by about 4°C in the last four decades. A new study, led by the University of Exeter, shows peatlands have expanded since 1950, with some peatland edges moving by more than a meter a year. The work has been published in Global Change Biology.

A new collaborative study, led by University of Utah Professor of atmospheric sciences Kevin Perry, provides policymakers, agency leaders, and the public with the most comprehensive assessment to date of potential dust control options for the Great Salt Lake, as declining water levels continue to expose vast areas of lakebed to wind erosion.

Researchers from the Aerospace Information Research Institute of the Chinese Academy of Sciences, in collaboration with Chongqing University of Posts and Telecommunications, have developed a high-resolution daily atmospheric carbon dioxide (CO2) dataset covering China from 2016 to 2020. The dataset offers new insights into the spatiotemporal variations of column-averaged dry-air CO2 mole fraction (XCO2). The work is published in the journal Scientific Data.

Minerals form the building blocks of almost everything on Earth. They are made up of crystals—regular, repeating atomic structures that fit together like a three-dimensional pattern. When minerals deform, their normally ordered crystal lattices develop linear imperfections known as dislocations. These are small breaks or shifts in the atomic arrangement that allow crystals to change shape under stress. Some deformed crystals contain large numbers of dislocations, while in others they are sparse and searching for them is like looking for a needle in a haystack.

While most of the world's glaciers are retreating as the climate warms, a small but significant population behaves very differently—and the consequences can be severe. A team of international scientists, led by the University of Portsmouth, has carried out a comprehensive global analysis of surging glaciers, examining the hazards they cause and how climate change is fundamentally altering when and where these dramatic events occur.

It is well documented that the Gulf Stream plays a pivotal role in the climate system through its transfer of heat, which ultimately supplies warmth to northern latitudes in the North Atlantic. What remains less well understood is how the Gulf Stream influences the climate system by transporting nutrients and carbon. These materials stimulate plankton growth, which in turn plays a vital role in naturally absorbing carbon dioxide from the atmosphere.

There's been a seismic shift in science, with scientists developing new AI tools and applying AI to just about any question that can be asked. Researchers are now putting actual seismic waves to work, using data from the world's largest repository of earthquake data to develop "SeisModal," an AI foundation model designed to explore big questions about science. The effort, known as Steel Thread, involves researchers from five national laboratories operated by the U.S. Department of Energy.

For obvious reasons, it would be useful to predict when an earthquake is going to occur. It has long been suspected that large quakes in the Himalayas follow a fairly predictable cycle, but nature, as it turns out, is not so accommodating. A new study published in the journal Science Advances shows that massive earthquakes are just as random as small ones. A team of researchers led by Zakaria Ghazoui-Schaus at the British Antarctic Survey reached this conclusion after analyzing sediments from Lake Rara in Western Nepal.

Geologists from St. Petersburg State University, as part of an international scientific team, have analyzed rock data from East Antarctica and determined that the magnetic anomaly in this region resulted from the convergence of continents and the birth of the supercontinent Rodinia approximately 1 billion years ago. The research is published in the journal Polar Science.

Current global climate models (GCMs) support with high confidence the view that rising greenhouse gases and other anthropogenic forcings account for nearly all observed global surface warming—slightly above 1 °C—since the pre-industrial period (1850–1900). This is the conclusion presented in the IPCC's Sixth Assessment Report (AR6) published in 2021.

Geographic information system (GIS) maps help researchers, policymakers, and community members see how environmental risks are spread throughout a given region. These types of interactive, layered maps can be used for storytelling, education, and environmental activism. When community members are involved in their use and creation, GIS maps can also be a tool for equity.

A new study reports that climate warming can increase soil carbon accumulation in boreal Sphagnum peatlands by boosting plant productivity, protecting iron, and inhibiting microbial decomposition. These responses contrast sharply with warming-enhanced soil carbon mineralization—the process by which carbon is released as CO2—in boreal forests and tundra. Together, these contrasting processes highlight the vital yet often overlooked role of Sphagnum peatlands in counteracting boreal carbon loss under future warming.

UK winters are becoming significantly wetter mainly due to warming driven by human burning of fossil fuels releasing greenhouse gases into the atmosphere, a Newcastle University study reveals. The research shows that for every degree of global or regional warming, winter rainfall increases by a compounding 7%, increasing the risk of flooding. And the scientists warn it is happening much faster than most global climate models predict.

Geologic reservoirs that trapped petroleum for millions of years are now being repurposed to store the greenhouse gas carbon dioxide. New research is improving how we monitor this storage and verify how much CO2 these reservoirs have stored.

Scientists have long known that Earth's core is mostly made of iron, but the density is not high enough for it to be pure iron, meaning lighter elements exist in the core, as well. In particular, it's suspected to be a major reservoir of hydrogen. A new study, published in Nature Communications, supports this idea with results suggesting the core contains up to 45 oceans' worth of hydrogen. These results also challenge the idea that most of Earth's water was delivered by comets early on.

Scientists say that multiple Earth system components appear closer to destabilization than previously believed, putting the planet in increased danger of following a "hothouse" path driven by feedback loops that can amplify the consequences of global warming.

The Murray-Darling Basin Authority (MDBA)—the statutory agency responsible for planning the Basin's water resources—has just shared the starkest news yet about the Basin's future: the Basin is almost certainly going to get hotter, drier, and more volatile in the future, with reduced river flows.

Water is made of hydrogen and oxygen, and sometimes these atoms are slightly heavier than usual. These heavier forms are called isotopes. As water evaporates or moves through the atmosphere, the amount of these isotopes changes in predictable ways. This can act as a fingerprint, allowing researchers to trace the movement of water at global scales.