Beavers Impact Ecosystems Above and Below Ground

Photo Credit: Gennady Zakharin

Above ground, we can see changes wrought by beaver ponds such as increases in biodiversity and water retention. But UConn Department of Earth Sciences researcher Lijing Wang says we have a limited understanding of how they impact what happens beneath the ground. In research published in Water Resource Research, Wang and co-authors study how water moves through the soils and subsurface environment and detail new insights into how beaver ponds impact groundwater.

Groundwater can be an important source of water for streams, especially late in a dry summer, it may be the only source of water sustaining a stream, says Wang, and researchers are interested in understanding if and how beaver ponds impact groundwater as these details are important to consider for water management and restoration efforts.

Retreating Glaciers May Send Fewer Nutrients to the Ocean

Northwestern Glacier in Alaska has retreated approximately 15 kilometers (nine miles) since 1950.
Photo Credit: Kiefer Forsch/Scripps Institution of Oceanography.

The cloudy, sediment-laden meltwater from glaciers is a key source of nutrients for ocean life, but a new study suggests that as climate change causes many glaciers to shrink and retreat their meltwater may become less nutritious. 

Led by scientists at UC San Diego’s Scripps Institution of Oceanography, the study finds that meltwater from a rapidly retreating Alaskan glacier contained significantly lower concentrations of the types of iron and manganese that can be readily taken up by marine organisms compared to a nearby stable glacier. These metals are scarce in many parts of the ocean including the highly productive Gulf of Alaska, and they are also essential micronutrients for phytoplankton, the microorganisms that form the base of most marine food webs.

Microbes at Red Sea vents show how life and geology shape each other

Microscopic images of the studied microbes.
Image Credit: Courtesy of King Abdullah University of Science and Technology

A new study led by King Abdullah University of Science and Technology (KAUST) Professor Alexandre Rosado has revealed an unusual microbial world in the Hatiba Mons hydrothermal vent fields of the central Red Sea, a site first discovered by one of his co-authors and colleagues, Assistant Professor Froukje M. van der Zwan. 

Published in Environmental Microbiome, the study delivers the first "genome-resolved" analysis of these hydrothermal systems, providing an unprecedented view into both the types of microbes present and the metabolic functions that sustain them. 

“Microbes from the Hatiba Mons fields show remarkable metabolic versatility,” said KAUST Ph.D. student and lead author of the study, Sharifah Altalhi. “By understanding their functions, we can see how life shapes its environment, and how geology and biology are deeply intertwined in the Red Sea.” 

Arctic in Transition: Greenland’s Caves Preserve Ancient Climate Archive

Inside the Cove Cave, northern Greenland: A team of Innsbruck scientists studies deposits from a time when the Arctic was much warmer than today.
Photo Credit: Robbie Shone

In a remote cave in northern Greenland, a research team led by geologists Gina Moseley, Gabriella Koltai, and Jonathan Baker have discovered evidence of a significantly warmer Arctic. The cave deposits show that the region was free of permafrost millions of years ago and responded sensitively to rising temperatures. The findings, published in Nature Geoscience, provide new insights into past climate conditions and their relevance for today’s climate protection efforts.

Understanding Earth’s climate during earlier warm periods is key to predicting how it may change in the future. One particularly revealing time is the Late Miocene, which began about 11 million years ago. During this period, Earth’s distribution of land and ocean was similar to today, and both temperatures and atmospheric CO₂ levels were comparable to projections for the coming decades. Although the Arctic is known to be highly sensitive to climate change, its environmental conditions during the Late Miocene have remained poorly understood.

What Is: Extinction Level Events

A Chronicle of Earth's Biotic Crises and an Assessment of Future Threats
Image Credit: Scientific Frontline

Defining Biotic Catastrophe

The history of life on Earth is a story of breathtaking diversification and innovation, but it is punctuated by chapters of profound crisis. These are the extinction level events—catastrophes of such magnitude that they fundamentally reset the planet's biological clock. Popular imagination often pictures a single, sudden event, like the asteroid that sealed the fate of the dinosaurs. The geological reality, however, is more complex and, in many ways, more instructive for our current era. Understanding these events requires a rigorous scientific framework that moves beyond simple notions of species loss to appreciate the systemic collapse of entire global ecosystems.

New study finds large fluctuations in sea level occurred throughout the last ice age, a significant shift in understanding of past climate

Photo Credit: Michael Chen

Large changes in global sea level, fueled by fluctuations in ice sheet growth and decay, occurred throughout the last ice age, rather than just toward the end of that period, a study published this week in the journal Science has found.

The findings represent a significant change in researchers’ understanding of how the Pleistocene – the geological period from about 2.6 million to 11,700 years ago and commonly known as the last ice age – developed, said Peter Clark Link is external, a paleoclimatologist at Oregon State University and the study’s lead author.

“This is a paradigm shift in our understanding of the history of the ice age,” said Clark, a university distinguished professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences.

During the last ice age, Earth experienced cycles of dramatic shifts in global sea level caused by the formation and melting of large ice sheets over northern areas of North America and Eurasia. These changes are recorded in the shell remains of microscopic marine organisms called foraminifera, which are found in ocean sediment and collected by drilling cores, giving scientists an important record of past climate history.

Geologists discover the first evidence of 4.5-billion-year-old “proto-Earth”

“This is maybe the first direct evidence that we’ve preserved the proto Earth materials,” says Nicole Nie. An artist’s illustration shows a rocky proto Earth bubbling with lava.
Image Credit: MIT News; iStock
(CC BY-NC-ND 4.0)

Scientists at MIT and elsewhere have discovered extremely rare remnants of “proto-Earth,” which formed about 4.5 billion years ago, before a colossal collision irreversibly altered the primitive planet’s composition and produced the Earth as we know today. Their findings, reported today in the journal Nature Geosciences, will help scientists piece together the primordial starting ingredients that forged the early Earth and the rest of the solar system.

Billions of years ago, the early solar system was a swirling disk of gas and dust that eventually clumped and accumulated to form the earliest meteorites, which in turn merged to form the proto-Earth and its neighboring planets.

In this earliest phase, Earth was likely rocky and bubbling with lava. Then, less than 100 million years later, a Mars-sized meteorite slammed into the infant planet in a singular “giant impact” event that completely scrambled and melted the planet’s interior, effectively resetting its chemistry. Whatever original material the proto-Earth was made from was thought to have been altogether transformed.

Earth’s continents stabilized due to furnace-like heat

A new study of the chemical components of rocks led by researchers at Penn State and Columbia University provides the clearest evidence yet for how Earth's continents became and remained so stable — and the key ingredient is heat. 
Photo Credit: Jaydyn Isiminger / Penn State
(CC BY-NC-ND 4.0)

The new discovery has implications beyond geologic history, such as the search for critical minerals and habitable planets beyond Earth

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. 

In a paper published today (Oct. 13) in the journal Nature Geoscience, the researchers demonstrated that the formation of stable continental crust — the kind that lasts billions of years — required temperatures exceeding 900 degrees Celsius in the planet’s lower continental crust. Such high temperatures, they said, were essential for redistributing radioactive elements like uranium and thorium. The elements generate heat as they decay, so as they moved from the bottom to the top of the crust, they carried heat out with them and allowed the deep crust to cool and strengthen.

Scientists uncover a new way to forecast eruptions at mid-ocean ridges through hydrothermal vent temperatures

Data loggers deployed at hydrothermal vents on the East Pacific Rise record temperature of vent fluids every ten minutes for up to a year.
Photo Credit: Photo courtesy of Jill McDermott, Lehigh Univ.; WHOI, NDSF, Alvin Team; Funder: National Science Foundation. © Woods Hole Oceanographic Institution

A new study provides scientists with a powerful new tool for monitoring and predicting tectonic activity deep beneath the seafloor at mid-ocean ridges—vast underwater mountain chains that form where Earth’s tectonic plates diverge.

The study, titled “Hydrothermal vent temperatures track magmatic inflation and forecast eruptions at the East Pacific Rise, 9°50'N,” reveals that fluctuations in the temperature of fluids flowing from hydrothermal vents occurring over minutes to years indicate the effects of magmatic and tectonic processes that occur miles beneath the seafloor. The research offers the first evidence that these subtle but detectable temperature changes could offer the means to predict seafloor volcanic eruptions.

Led by Thibaut Barreyre of the French National Centre for Scientific Research (CNRS) and University of Brest, with collaborators from Woods Hole Oceanographic Institution (WHOI), Lehigh University, and Scripps Institution of Oceanography, the study presents a 35-year time-series of temperature measurements from five hydrothermal vents along the East Pacific Rise, one of the most active segments and well-studied of the global mid-ocean ridge system.

Understanding volcanoes better

Oldoinyo Lengai in Tanzania is the only active carbonatite volcano on Earth.
Photo Credit: © Miriam Reiss

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. "We were not only able to detect tremor, but also to determine its exact position in three dimensions – its location and depth below the surface," said Reiss. "What was particularly striking was the diversity of different tremor signals we detected." The findings provide new insights into how magma and gas are transported within the Earth and thus improve our understanding of volcanic dynamics. This also has societal relevance as the researchers hope that their work will enhance the ability to forecast volcanic eruptions in the long term. Their results have recently been published in Communications Earth & Environment.

The Red Sea Went Completely Dry Before Being Flooded by the Indian Ocean

 KAUST scientists have determined a rapid flood more than 6 million years ago radically changed the Red Sea and all its marine life.
Photo Credit: Francesco Ungaro

KAUST researchers find the Red Sea experienced a massive disruption 6.2 million years ago completely changing its marine life 

Scientists at King Abdullah University of Science and Technology (KAUST) have provided conclusive evidence that the Red Sea completely dried out about 6.2 million years ago, before being suddenly refilled by a catastrophic flood from the Indian Ocean. The findings, published in Communications Earth & Environment, put a definitive time on a dramatic event that changed the Red Sea. 

Using seismic imaging, microfossil evidence, and geochemical dating techniques, the KAUST researchers showed that a massive change happened in about 100 000 years – a blink of an eye for a major geological event. The Red Sea went from connecting with the Mediterranean Sea to an empty, salt-filled basin. Then, a massive flood burst through volcanic barriers to open the Bab el-Mandab strait and reconnect the Red Sea with the world’s oceans. 

“Our findings show that the Red Sea basin records one of the most extreme environmental events on Earth, when it dried out completely and was then suddenly reflooded about 6.2 million years ago,” said lead author Dr. Tihana Pensa of KAUST. “The flood transformed the basin, restored marine conditions, and established the Red Sea’s lasting connection to the Indian Ocean.” 

What Is: El Niño, La Niña, and a Climate in Flux

Image Credit: Scientific Frontline / NOAA

The Planet's Most Powerful Climate Cycle

In 1997, a climatic event of unprecedented scale began to unfold in the tropical Pacific Ocean. Dubbed the "El Niño of the century," it triggered a cascade of extreme weather that reshaped global patterns for over a year. It unleashed devastating floods and droughts, sparked massive forest fires, decimated marine ecosystems, and crippled national economies. By the time it subsided in 1998, the event was estimated to have caused more than 22,000 deaths and inflicted over $36 billion in damages worldwide. Nearly two decades later, the powerful 2015-16 El Niño, supercharged by a background of long-term global warming, helped propel 2016 to become the hottest year on record and directly impacted the lives and livelihoods of over 60 million people.

These catastrophic events are not random acts of nature but manifestations of the planet's most powerful and influential climate cycle: the El Niño-Southern Oscillation (ENSO). This naturally occurring phenomenon is a periodic, irregular fluctuation of sea surface temperatures and atmospheric pressure across the vast expanse of the equatorial Pacific Ocean. At its heart are two opposing phases: El Niño ("The Little Boy" in Spanish), a significant warming of the ocean surface, and La Niña ("The Little Girl"), a countervailing cooling. Together with a neutral "in-between" state, they form a planetary-scale pendulum that swings irregularly every two to seven years, dictating patterns of drought and flood, storm and calm, across the globe.

Heatwaves at Sea May Force the Ocean to Release More CO2

Marine heatwaves are disrupting the ocean’s ability to store carbon
Image Credit: Scientific Frontline / AI generated

Heatwaves not only occur on land – they also occur in the oceans, causing ocean temperatures to stay warmer than normal for longer periods. Marine heatwaves can cover huge areas of the sea and have major effects on marine life, from plankton to reefs and whales.

Now, a new study shows that marine heatwaves may also affect how carbon is stored in the ocean.

The ocean is one of Earths biggest carbon sinks. It soaks up vast amounts of CO2 from the atmosphere, and in the surface water, algae and other photosynthetic microorganisms capture it and convert it to organic carbon. When these organisms die and sink to the bottom, the carbon sinks with them. In the deep ocean, the removed carbon can be locked away for hundreds, even thousands of years.

Volcanic ash may enhance phytoplankton growth in the ocean over 100 km away

Nishinoshima Island, located in the Ogasawara Islands of Japan, is home to an active volcano. Ash from volcanic eruptions there in 2020 could have led to a temporary surge in phytoplankton levels in the seawater 130 km away.
Photo Credit: Ogasawara Village Tourism Bureau

A research group in Japan has suggested that ash released from volcanic eruptions on Nishinoshima Island—part of Japan's Ogasawara Islands—led to a temporary surge in phytoplankton levels in the seawater around Mukojima Island, which is located 130 km northeast of Nishinoshima and is also part of the Ogasawara Islands.

Mukojima lies within the subtropical gyre, a region known for low nutrient and low chlorophyll conditions. The study indicates that ash from the Nishinoshima eruptions was transported by wind and ocean currents to the waters around Mukojima, serving as a nutrient source for phytoplankton growth in that area.

Cascadia and San Andreas faults may be seismically linked

Chris Goldfinger
Photo Credit: Courtesy of Oregon State University

Two fault systems on North America’s West Coast – the Cascadia subduction zone and the San Andreas fault – may be synchronized, with earthquakes on one fault potentially triggering seismic events on the other, a new study.

“We’re used to hearing the ‘Big One’ – Cascadia – being this catastrophic huge thing,” said Chris Goldfinger Link is external, a marine geologist at Oregon State University and lead author of the study. “It turns out it’s not the worst-case scenario.”

Goldfinger and a team of researchers drilled deep-sea sediment cores representing 3,100 years of geologic history, and analyzed layers known as turbidites that are deposited by underwater landslides often triggered by earthquakes. They compared turbidite layers in cores from both fault systems and found similarities in timing and structure, suggesting the seismic synchronization between the faults.

In most cases, it’s difficult to determine the time separation between the Cascadia subduction zone and northern San Andreas fault ruptures, but Goldfinger said there are three instances in the past 1,500 years, including a most recent one from 1700, when the researchers believe the ruptures were just minutes to hours apart.

Rare glimpse at understudied ecosystem prompts caution on deep-sea mining

Some of the animals identified in the deep-sea that spend their life in the benthic boundary layer.
Photo Credit: Gabrielle Ellis

An enormous but poorly understood region of the global ocean–referred to as the abyssal benthic boundary layer–lies a few meters above the seafloor and has only been sampled a handful of times. A study by oceanographers at the University of Hawaiʻi at Mānoa provided the first in-depth look at this habitat, revealing a dynamic community that may be more sensitive to seasonal changes than previously understood. The research, published in Limnology and Oceanography, also concluded that deep-sea mining could have significant and unavoidable impacts on biodiversity, regardless of the time of year.

“Given the remoteness of this environment, we have extraordinarily limited knowledge of the animals that inhabit this zone,” said Gabrielle Ellis, lead author of the study and recent oceanography graduate from the UH Mānoa School of Ocean and Earth Science and Technology. “This study represents a significant contribution to our understanding of the benthic boundary layer community, and it starts to unravel temporal dynamics in the abyss.”

The first animals on Earth may have been sea sponges, study suggests

Some of the first animals on Earth were likely ancestors of the modern sea sponge, according to MIT geochemists who unearthed new evidence in very old rocks.
Image Image: Jose-Luis Olivares, MIT
(CC BY-NC-ND 4.0)

A team of MIT geochemists has unearthed new evidence in very old rocks suggesting that some of the first animals on Earth were likely ancestors of the modern sea sponge.

In a study appearing today in the Proceedings of the National Academy of Sciences, the researchers report that they have identified “chemical fossils” that may have been left by ancient sponges in rocks that are more than 541 million years old. A chemical fossil is a remnant of a biomolecule that originated from a living organism that has since been buried, transformed, and preserved in sediment, sometimes for hundreds of millions of years.

The newly identified chemical fossils are special types of steranes, which are the geologically stable form of sterols, such as cholesterol, that are found in the cell membranes of complex organisms. The researchers traced these special steranes to a class of sea sponges known as demosponges. Today, demosponges come in a huge variety of sizes and colors, and live throughout the oceans as soft and squishy filter feeders. Their ancient counterparts may have shared similar characteristics.

Supercritical subsurface fluids open a window into the world

Interpreted 3D seismic characteristics.
The seal layer, interpreted by looking at data on the supercritical fluid’s movement, appears as a distinct region. It’s disrupted where it meets a fault which makes it appear porous to the fluid, allowing it to migrate upwards, causing seismic vibrations.
Image Credit: ©2025 Tsuji et al.
(CC BY 4.0)

Researchers including those from the University of Tokyo build on past studies and introduce new methods to explore the nature and role of subsurface fluids including water in the instances and behaviors of earthquakes and volcanoes. Their study suggests that water, even heavy rainfall, can play a role in or even trigger seismic events. This could potentially lead to better early warning systems. The study improves models of seismic activity and can even help identify optimal sites for drilling to tap sources of supercritical geothermal energy.

As far as is currently known, earthquakes and volcanic eruptions cannot be predicted, certainly not on the timescales with which we expect from typical weather reports. But as physical theories improve, so does the accuracy of statistical models which could be useful for planning, and potentially also early warning systems, which can save lives when disaster does strike. Another benefit of improving such models is that they could help locate areas suitable for tapping into geothermal energy. So, it’s the improvement of theories, based on good observations, that geologists and other researchers strive for. And a recent development in this field has added another factor into the mix which may be more significant than was previously thought.

Rivers in the Sky, Arctic Warming, and What this Means for the Greenland Ice Sheet

Photo Credit: Beau Mori

 “Atmospheric rivers” are large-scale extreme weather systems that are making headlines more frequently. When viewed in satellite images, they appear just as described – like rivers in the sky. Though they are often reported in places like California, these weather systems have the potential to bring high heat and dump disastrous amounts of precipitation on areas throughout the mid and high latitudes.

A team of researchers, including UConn Department of Earth Sciences associate professor Clay Tabor and Ph.D. student Joseph Schnaubelt, looked at how atmospheric rivers impacted the Greenland Ice Sheet in the past to get a better understanding of how these weather systems may enhance melting in the Arctic as the climate continues to warm. Their results are published in AGU Advances.

An important question that paleoclimate scientists like Schnaubelt and Tabor are trying to answer is how the Arctic will respond to climate change, and for this they focused deep into the past on a time called the Last Interglacial, between 130,000 and 115,000 years ago.

“Earth goes through glacial cycles, and the Last Interglacial was the last time the Arctic was warmer than present day,” says Schnaubelt. “We know that that’s the direction we’re headed toward, and we wanted to see how atmospheric rivers impacted the Greenland Ice Sheet.”

Ice dissolves iron faster than liquid water

When ice freezes and thaws repeatedly, chemical reactions are fuelled that can have significant impact on ecosystems. The photo was taken in Stordalen, Abisko.
Photo Credit: Jean-François Boily

Ice can dissolve iron minerals more effectively than liquid water, according to a new study from Umeå University. The discovery could help explain why many Arctic rivers are now turning rusty orange as permafrost thaws in a warming climate.

The study, recently published in the scientific journal PNAS, shows that ice at minus ten degrees Celsius releases more iron from common minerals than liquid water at four degrees Celsius. This challenges the long-held belief that frozen environments slow down chemical reactions.

“It may sound counterintuitive, but ice is not a passive frozen block,” says Jean-François Boily, Professor at Umeå University and co-author of the study. “Freezing creates microscopic pockets of liquid water between ice crystals. These act like chemical reactors, where compounds become concentrated and extremely acidic. This means they can react with iron minerals even at temperatures as low as minus 30 degrees Celsius.”