Phys.org: Earth science

For billions of years, Earth's continents have remained remarkably stable, forming the foundation for mountains, ecosystems and civilizations. But the secret to their stability has mystified scientists for more than a century. Now, a new study by researchers at Penn State and Columbia University provides the clearest evidence yet for how the landforms became and remained so stable—and the key ingredient is heat.

Deep inside caves, water dripping from the ceiling creates one of nature's most iconic formations: stalagmites. These pillars of calcite, ranging from centimeters to many meters in height, rise from the cave floor as drip after drip of mineral-rich water deposits a tiny layer of stone.

Accurately modeling gross primary productivity (GPP) and evapotranspiration (ET) in terrestrial ecosystems is essential for understanding and predicting the global carbon and water cycles. However, current models face considerable uncertainties and limitations when estimating these two core components.

An international research team led by the University of Bremen has investigated what influenced the expansion of the Patagonian ice sheet during the last ice age. The scientists found evidence that the advances and retreats of glaciers in South America over the past 120,000 years were primarily influenced by changes in summer solar radiation and the duration of the summers.

A new study has challenged the long-standing assumption that global warming will inevitably turn humid subtropical forests into carbon sources, revealing these ecosystems may instead continue accumulating soil carbon under moderate temperature rises. The study was published in One Earth on Oct. 6.

Magnetotelluric (MT) data, which contain measurements of electric and magnetic field variations at Earth's surface, provide insights into the electrical resistivity of Earth's crust and upper mantle. Changes in resistivity, or the ability to conduct an electrical current, can indicate the presence of geologic features such as igneous intrusions or sedimentary basins, meaning MT surveys can complement other kinds of geophysical surveys to help reveal Earth's subsurface. In addition, such surveys can play an important role in improving understanding of the risks space weather poses to human infrastructure.

How do volcanoes work? What happens beneath their surface? What causes the vibrations—known as tremor—that occur when magma or gases move upward through a volcano's conduits? Professor Dr. Miriam Christina Reiss, a volcano seismologist at Johannes Gutenberg University Mainz (JGU), and her team have located such tremor signals at the Oldoinyo Lengai volcano in Tanzania.

According to a study by the Department of Physics and the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB), the Mar Menor saltwater lagoon in Murcia, Spain, the largest in Europe, contains sediments with levels of lead, arsenic, zinc, mercury, copper, and silver that exceed toxicity thresholds and values reported for similar coastal ecosystems worldwide. The findings are published in the journal Marine Pollution Bulletin.

Heat waves in the UK have led to unseasonable drying of vegetation bypassing natural ecological processes that limit the spread of wildfires, a new study has found.

Greenland is melting, the Alps are melting and the Himalayas are melting—yet in one vast mountain region, huge glaciers have remained stable, or even gained mass, in recent decades. Can it last?

A new fossil fuel site approved for development off Western Australia's coast is estimated to contribute 876 million tons of carbon dioxide (CO2) emissions over the course of its lifetime, according to new research led by The Australian National University (ANU) in collaboration with the ARC Center of Excellence for the Weather of the 21st century.

The world faces a "new reality" as we have reached the first of many Earth system tipping points that will cause catastrophic harm unless humanity takes urgent action, according to a report released by the University of Exeter and international partners.

The timing of emissions reductions, even more so than the rate of reduction, will be key to avoiding catastrophic thresholds for ice-melt and sea-level rise, according to a new Cornell University study.

Glaciers are fighting back against climate change by cooling the air that touches their surfaces. But for how long? The Pellicciotti group at the Institute of Science and Technology Austria (ISTA) has compiled and re-analyzed an unprecedented dataset of on-glacier observations worldwide. Their findings, published today in Nature Climate Change, demonstrate that glaciers will likely reach the peak of their self-cooling power by the next decade before their near-surface temperatures spike up and melting accelerates.

Guided by the rhythms of the sea and the promise of discovery, Teledyne Marine and Rutgers University will set Redwing, an autonomous underwater vehicle, on its journey on Friday, Oct. 10, leading to its launch into the Atlantic Ocean off the coast of Martha's Vineyard in Massachusetts.

New research from the University of St Andrews has shed light on a crucial mechanism of lowering atmospheric CO2 during Earth's past ice ages.

Dry soils in northern Mexico may trigger episodes of simultaneous drought and heat wave hundreds of miles away in the southwestern United States, such as Arizona, New Mexico, and Texas, according to a new study. These "hot droughts" in the region increasingly persist through consecutive days and nights rather than easing up after sundown, the research also found, leaving no window for afflicted areas to recover.

An EPFL engineer has illustrated some of the complex ways in which climate change will affect hydropower facilities, taking the Gries dam in Valais Canton as a case study.

As climate change continues to reshape the intensity and behavior of hurricanes, meteorologists and researchers are examining whether the Saffir-Simpson Hurricane Wind Scale, a decades-old classification system, still adequately communicates the full scope of hurricane hazards. While the scale remains a widely recognized tool, experts like Zachary Handlos, director of Atmospheric and Oceanic Sciences at Georgia Tech, suggest that a complementary system could enhance public understanding of the broader risks hurricanes pose.

Since the 1980s, scientists have known fine roots (< 2 mm) are critical to ecosystem carbon cycling, with research long suggesting their contribution to soil carbon accrual may exceed that of aboveground plant parts like leaves. Yet more than 40 years later, a key knowledge gap remains: the role of multi-decadal root iterative dynamics (growth, turnover, decomposition) in soil carbon accumulation—especially for "absorptive roots," the finest, most metabolically active roots (typically the distal 2–3 root orders or < 0.5 mm in diameter).