Phys.org: Earth science

Ice cores recovered from an ice cap in northwestern Tibet appear to preserve fragments of ancient ice from the last ice age, extending Earth's glacial record by more than 100,000 years and making them the oldest ice cores ever recovered from the region, according to a new study.

A few days of rain do not change low groundwater levels after a long drought. To better determine how groundwater systems recover after a drought and which groundwater reserves are most vulnerable, hydrologist Sandra Hauswirth developed a method to classify groundwater systems based on their ability to recover from prolonged drought.

Irrigation canals form a sort of circulatory system for global agriculture. Across the world, millions of kilometers of human-made canals carry water from lakes, rivers and reservoirs downhill to farmland. Canals are vitally important to human food production, yet many agricultural areas lack the means to monitor the ebb and flow of water through these waterways. This forces farmers and water managers to rely on scattered gauges, inspections and local reports to make decisions about water use.

Sea-level rise is one of the most visible signs of climate change, one that is threatening low-lying coastal communities around the world. Today, about 1 billion people live in coastal areas; about 100 million live within 1 meter (3.3 feet) of sea level, highly exposed to coastal flooding.

Many cities around the world are sinking because too much water is extracted from the groundwater reservoirs beneath them. This sinking makes these coastal cities more exposed to rising seas as the climate warms. But as our new research shows, this process can work in reverse: When groundwater is replenished, cities can rise.

Over a century ago, Australian geologist Sir Douglas Mawson led a sledding expedition over hundreds of kilometers of ice into a remote part of East Antarctica. The party turned back after the tragic death of a party member. Fellow Australian Cecil Madigan led another group across sea ice into the region before also turning back.

In 2025, along parts of Kamchatka's coast in Russia, a magnitude 8.8 earthquake caused a tsunami to surge nearly 20 meters (65 feet) above sea level. Yet across the Pacific, its waves were much smaller than those produced by the region's great 9.0 earthquake in 1952. How could the tsunami climb so high near the source yet have a comparatively modest impact far away?

From the air, Wainwright, Alaska, looks like a perfectly stable band of homes and roads between the Chukchi Sea and a vast, flat tundra. But just below the surface, the frozen ground on which this town was built contains large bodies of ice. Along the eroding coastal bluffs, that hidden ice is becoming exposed and melting away.

While not quite a fatal attraction, the gravitational pull of the moon and sun creates tiny stresses on Earth that can trigger events known as slow earthquakes. These are movements along fault lines (fault slips) that release their energy gradually over much longer periods than ordinary quakes. Although they have been observed, exactly how these celestial bodies trigger them has been a relatively tough nut to crack.

Three much-loved glaciers in British Columbia are set to disappear completely within a few decades, according to a Simon Fraser University study.

Climate patterns in the tropics help determine how much snow falls from year to year in Antarctica, one of the coldest, windiest and driest places on Earth. New research from the University of Utah shows that tropical conditions and the oceans also influence the continent's massive ice sheets.

The South Asian summer monsoon has long been known to shape the Mediterranean climate thousands of kilometers away as part of a phenomenon known as the "monsoon–desert" mechanism. Through this mechanism, intense monsoon convection during the summer releases large amounts of heat into the atmosphere, triggering large-scale circulation changes that promote sinking air over the Mediterranean. This process suppresses clouds and rainfall and contributes to the Mediterranean region's hot, dry climate.

Extending some 1,200 kilometers (750 miles) along the length of Italy, the Apennine Mountains present a challenging puzzle for geologists. In some places, the mountains are steadily being stretched apart, while in regions just tens of kilometers away, they are squeezing together.

Lakes may cover only a small fraction of Earth's surface, but new research suggests they play a bigger role in regulating the planet's climate than previously recognized. By reflecting sunlight back into space when covered in snow and ice, lakes in the Northern Hemisphere have a stronger cooling effect than the surrounding land.

Weather forecasts in the Southern Hemisphere (SH) are generally less accurate than those in the Northern Hemisphere because Antarctica and the surrounding Southern Ocean have relatively few weather observations. With limited information about atmospheric conditions in one of the world's most remote regions, forecasting models often struggle to predict the movement of weather systems. This is especially true for atmospheric rivers that can trigger heavy rain, snowfall, flooding and strong winds across Australia, New Zealand, South America and Antarctica. Improving forecasts of these weather systems is essential for protecting lives and property, supporting aviation and shipping, and helping communities prepare for hazardous weather.

When we think of a volcanic eruption, rivers of glowing lava or giant columns of ash come to mind. But beneath Earth's surface, a more complex story is unfolding. Magma deep within volcanoes is more than molten rock. It is a thick mixture of melted rock and solid mineral crystals known as "magma mush". To picture it, imagine a semi-frozen granita: a slushy blend of solid ice crystals suspended in sweet liquid syrup.

When Pliny the Younger recorded his firsthand experience of the eruption of Mount Vesuvius 2,000 years ago—a cataclysm that buried Pompeii and killed his uncle, Pliny the Elder—he provided enough detail about the date to allow scientists to benchmark methods for dating volcanic eruptions.

Returning global temperatures to a climate target does not necessarily undo the damage caused by exceeding it, new Concordia-led research published in the journal Communications Earth & Environment finds.

Dryland ecosystems cover 40% of the Earth's land surface and support more than 2 billion people. According to a new study published in Nature Climate Change, they're becoming increasingly unstable.

In northeastern North America, a stretch of mountains runs 500 miles (800 kilometers) from the Adirondacks in New York to the Gaspé Peninsula in eastern Quebec. Nearly 70 million people live within a day's drive of one of the alpine zones, the areas above the tree line where trees don't grow because of harsh conditions.