Phys.org: Earth science

Tropical cyclones are hurricanes that brew over the tropical ocean and can travel over land, inundating coastal regions. The most extreme cyclones can generate devastating storm tides—seawater that is heightened by the tides and swells onto land, causing catastrophic flood events in coastal regions.

Imagine if Earth's history had a mystery novel, and one of its biggest unsolved puzzles was: Where did all the nitrogen go? Scientists have long known that our planet's rocky outer layers—the mantle—are oddly poor in nitrogen compared to other volatile elements like carbon or water. Very strangely, the C/N and 36Ar/N ratios in the bulk silicate Earth (BSE, the whole Earth minus the metallic core) are far higher than those found in the meteorites that supposedly delivered these ingredients during the planet's infancy.

Research led by the Union of Concerned Scientists reports that emissions from the world's largest fossil fuel and cement companies have contributed significantly to both present-day and long-term sea level rise. Products from 122 major producers have contributed up to 37% of the rise in global sea level observed through 2022 and may account for an additional 0.26 to 0.55 meters by 2300.

Sustained scientific observations and monitoring are crucial for measuring ocean change, providing valuable data that contributes to a better understanding of oceanography, biodiversity, and the interconnectedness of global systems, and helps inform decisions about conservation and resource management.

What is the role of dissolved organic matter in the deep sea? In a study relating to this question, researchers from the Universities of Bremen and Oldenburg have investigated the composition of dissolved organic matter (DOM) in detail. Their samples were obtained during an expedition to the Guaymas Basin in the Gulf of California.

Nearly three-fourths of Earth is covered by oceans, making the planet look like a pale blue dot from space. But Japanese researchers have made a compelling case that Earth's oceans were once green, in a study published in Nature.

Newly published research has revealed that compositional rock anomalies within oceanic plates caused by ancient tectonics influence the trajectory and speed of the plates as they plunge deep into Earth's mantle.

When the Kīlauea Volcano erupted in May 2018, an enormous amount of ash was released into the atmosphere in a plume nearly five miles high. A new study by an international team of researchers revealed that a rare and large summertime phytoplankton bloom in the North Pacific Subtropical Gyre in the summer of 2018 was prompted by ash from Kīlauea falling on the ocean surface approximately 1,200 miles west of the volcano. The research was published recently in the Journal of Geophysical Research: Oceans.

As extreme weather and flooding events become more intense and frequent due to climate change, improving flood mitigation strategies has never been more critical. The livelihood of downstream communities relies heavily on effective flood resilience measures to reduce flood levels and decrease the power of flood waters.

A new study reveals the modern arid desert between Africa and Saudi Arabia was once regularly lush and green with rivers and lakes over a period of 8 million years, allowing for the occupation and movements of both animals and hominins. The study "Recurrent humid phases in Arabia over the past 8 million years" has been published in Nature.

For generations, sailors around the globe have reported a mysterious phenomenon: Vast areas of the ocean glow steadily at night, sometimes for months on end. The light is bright enough to read by and is oddly similar to the green and white aura cast by glow-in-the-dark stars that have decorated children's rooms. Stretching over ocean space as broad as 100,000 square kilometers, the light can, at times, even be seen from space.

Unexpectedly strong methane emissions have been detected at several locations in Lake Siljan, Sweden, according to a new study from Chalmers University of Technology. The findings, based on a novel measurement technique developed by the researchers, reveal persistent and concentrated methane leaks never before observed in a lake environment. Scientists will now investigate whether these emissions are unique to Siljan—or part of a broader phenomenon that could occur in lakes worldwide.

We have to stop emitting carbon dioxide (CO2) if we want to save the climate—there is no doubt about that. But that alone will not be enough. In addition, it will also be necessary to capture CO2 that is already present in the atmosphere, and store it permanently, for example, by pumping it deep into the ground.

About 66 million years ago, an asteroid slammed into the planet, wiping out all non-avian dinosaurs and about 70% of all marine species.

While the daily ebb and flow of people across a city might seem chaotic, new research reveals underlying universal patterns. A study published in the journal Nature Communications by a team led by Chair Professor Bo Huang from the Department of Geography at the University of Hong Kong (HKU) unveils fundamental spatiotemporal scaling laws that govern these population dynamics.

Chengdu University of Technology-led research has established a high-resolution astrochronological framework spanning approximately 57.6 million years of the early Ediacaran Period. This calibrated timeline provides precise constraints on major climatic events and the appearance of early complex life, offering critical context for understanding environmental change and biological innovation during Earth's early history.

A team of Earth scientists affiliated with Peking University and the Southern University of Science and Technology, both in China, and a researcher from the University of Southern California, in the U.S., have found that the land below parts of the Aral Sea that have dried up over the past several decades is slowly rising.

For hundreds of years, the Amazon has been exploited for its gold. Today, the precious metal is just as sought after, but the remaining tiny gold particles are much harder to find. Mining often happens in artisanal and small-scale mining operations that release mercury (Hg) into the air, polluting the environment and harming human health.

Airborne dust pollution is a growing problem for residents of Utah and other Western states, especially with the exposed lakebed of Great Salt Lake potentially becoming more hazardous as the lake dries. Natural dust blows from the Great Basin and settles along the western edge of the Wasatch Front, Utah's major population center, and the surrounding mountains.

The winter growth period for sea ice in the Arctic Ocean is now over, with levels at a record low. The winter ice extent on 21 March 2025 was lower than at any time since continuous satellite recording began in 1979.