https://www.scivillage.com/ Wed, 12 Aug 2026 15:27:39 +0000 MyBB https://www.scivillage.com/thread-21059.html Mon, 10 Aug 2026 19:12:13 +0000 C C]]> https://www.scivillage.com/thread-21059.html https://arstechnica.com/science/2026/08/...r-species/

EXCERPTS: Mount Toba was the biggest volcanic eruption in the last 2.6 million years, and some have suggested it nearly wiped out humanity. Around 74,000 years ago, a caldera on what is now Sumatra emptied thousands of cubic kilometers of magma in about two weeks, roughly a thousand times more than Mount Pinatubo spewed out in 1991. “People thought it might have caused massive cooling of the planet, and hence threatened the survival of our ancestors,” says Jinheum Park, a geoscientist at Johannes Gutenberg University in Mainz, Germany.

Park and his colleagues went looking for the records of that catastrophe in the mud taken from the bottom of a small crater lake on the Kenya-Tanzania border. They found instead that the effects of the Mount Toba eruption lasted under two years and amounted to perhaps half a degree of cooling.

[...] “The eruption did cool and dry the region, just not to such an extent as to significantly threaten the survival of humans,” Park argues. Across the 450-year window his team analyzed, eastern equatorial Africa was already sliding from a warmer, wetter regime into a cooler, drier one, tracking a natural cooling trend recorded in Greenland ice. Against that background, Toba’s impact looks tiny. “Our study shows that the magnitude of cooling and drying after Toba was much smaller, and within the natural range of variation in the last glacial–interglacial cycles,” Park says. “Humans had already experienced and survived that.”

The limitation in Park’s study is that Chala is just one lake. “It records the regional climate signals in eastern Africa, but it doesn’t show the impact on the whole globe,” Park explains. “There should be more studies using a similar approach, at more sites where the Toba ash is found.”

The team also hopes similar approaches will be used to learn more about other huge volcanic eruptions like Los Chocoyos in Guatemala and the Oruanui eruption in New Zealand 26,000 years ago. “They were not as big as Toba, but they were still super-eruptions. It would be interesting and exciting to see what happened,” Park says... (MORE - missing details)]]> https://arstechnica.com/science/2026/08/...r-species/

EXCERPTS: Mount Toba was the biggest volcanic eruption in the last 2.6 million years, and some have suggested it nearly wiped out humanity. Around 74,000 years ago, a caldera on what is now Sumatra emptied thousands of cubic kilometers of magma in about two weeks, roughly a thousand times more than Mount Pinatubo spewed out in 1991. “People thought it might have caused massive cooling of the planet, and hence threatened the survival of our ancestors,” says Jinheum Park, a geoscientist at Johannes Gutenberg University in Mainz, Germany.

Park and his colleagues went looking for the records of that catastrophe in the mud taken from the bottom of a small crater lake on the Kenya-Tanzania border. They found instead that the effects of the Mount Toba eruption lasted under two years and amounted to perhaps half a degree of cooling.

[...] “The eruption did cool and dry the region, just not to such an extent as to significantly threaten the survival of humans,” Park argues. Across the 450-year window his team analyzed, eastern equatorial Africa was already sliding from a warmer, wetter regime into a cooler, drier one, tracking a natural cooling trend recorded in Greenland ice. Against that background, Toba’s impact looks tiny. “Our study shows that the magnitude of cooling and drying after Toba was much smaller, and within the natural range of variation in the last glacial–interglacial cycles,” Park says. “Humans had already experienced and survived that.”

The limitation in Park’s study is that Chala is just one lake. “It records the regional climate signals in eastern Africa, but it doesn’t show the impact on the whole globe,” Park explains. “There should be more studies using a similar approach, at more sites where the Toba ash is found.”

The team also hopes similar approaches will be used to learn more about other huge volcanic eruptions like Los Chocoyos in Guatemala and the Oruanui eruption in New Zealand 26,000 years ago. “They were not as big as Toba, but they were still super-eruptions. It would be interesting and exciting to see what happened,” Park says... (MORE - missing details)]]> https://www.scivillage.com/thread-21018.html Mon, 03 Aug 2026 14:18:55 +0000 C C]]> https://www.scivillage.com/thread-21018.html https://www.eurekalert.org/news-releases/1138147

INTRO: Along the three coasts of the contiguous United States, a silent race unfolds. Fueled by climate change, sea levels rise faster than at any time in recent geologic history. Meanwhile, coastal wetlands cling to a slim lead, lifted on newly accumulated sediments or moving inland as encroaching tides nip at their heels.

Now, the first national-level study of this competition reveals that coastal wetlands — among the country’s most valuable ecosystems, protecting infrastructure and providing homes for wildlife — are losing ground: 84% are gradually inundating, with many on track to transform into open water. Wetlands along the Gulf Coast are generally faring the worst while certain stretches of the Atlantic Coast appear more resilient. Some wetlands may be able to migrate inland or build up sediment fast enough to keep pace with sea level rise, perhaps with the right help from land managers.

“Our study provides wetland managers with new information to help them make better-informed decisions and identify meaningful solutions to issues they may be encountering, including to facilitate wetland migration upslope,” said Glenn Guntenspergen, a coastal wetland ecologist with the U.S. Geological Survey and senior author on the study.

The study will appear Monday, 3 August in Earth’s Future, AGU’s journal for research on the state of the planet and its inhabitants and their future resilience in the Anthropocene... (MORE - no ads)]]> https://www.eurekalert.org/news-releases/1138147

INTRO: Along the three coasts of the contiguous United States, a silent race unfolds. Fueled by climate change, sea levels rise faster than at any time in recent geologic history. Meanwhile, coastal wetlands cling to a slim lead, lifted on newly accumulated sediments or moving inland as encroaching tides nip at their heels.

Now, the first national-level study of this competition reveals that coastal wetlands — among the country’s most valuable ecosystems, protecting infrastructure and providing homes for wildlife — are losing ground: 84% are gradually inundating, with many on track to transform into open water. Wetlands along the Gulf Coast are generally faring the worst while certain stretches of the Atlantic Coast appear more resilient. Some wetlands may be able to migrate inland or build up sediment fast enough to keep pace with sea level rise, perhaps with the right help from land managers.

“Our study provides wetland managers with new information to help them make better-informed decisions and identify meaningful solutions to issues they may be encountering, including to facilitate wetland migration upslope,” said Glenn Guntenspergen, a coastal wetland ecologist with the U.S. Geological Survey and senior author on the study.

The study will appear Monday, 3 August in Earth’s Future, AGU’s journal for research on the state of the planet and its inhabitants and their future resilience in the Anthropocene... (MORE - no ads)]]> https://www.scivillage.com/thread-20993.html Fri, 31 Jul 2026 16:48:00 +0000 C C]]> https://www.scivillage.com/thread-20993.html The gift that just keeps on giving. The only GOP hope for saving the midterms is Dems very possibly bumbling far more with other things than what Trump has with this unpopular war.
- - - - - - - - - - - - -

Ships stranded by war could cause marine ‘superspreader’ event, study warns
https://www.washingtonpost.com/world/202...ists-warn/

INTRO: New research warns that thousands of ships stranded for months by the ongoing war with Iran and the closed Strait of Hormuz could result in “a massive marine invasive species event.”

The study, led by scientists at the University of Maryland and the Woods Hole Oceanographic Institution, said the estimated 1,500 commercial vessels idled by war are likely now coated with marine microbes, algae and invertebrates.

The ships have sat submerged in the same waters for months, creating idle conditions for what the scientists call “biofouling.”

The scientists are now worried about what could happen when these ships eventually resume their journeys around the world. The study cites “the high likelihood” that the vessels will speed the spread of “economically and ecologically damaging invasive species.”

The threats posed by stranded ships are well-known and long-documented... (MORE - details)]]> The gift that just keeps on giving. The only GOP hope for saving the midterms is Dems very possibly bumbling far more with other things than what Trump has with this unpopular war.
- - - - - - - - - - - - -

Ships stranded by war could cause marine ‘superspreader’ event, study warns
https://www.washingtonpost.com/world/202...ists-warn/

INTRO: New research warns that thousands of ships stranded for months by the ongoing war with Iran and the closed Strait of Hormuz could result in “a massive marine invasive species event.”

The study, led by scientists at the University of Maryland and the Woods Hole Oceanographic Institution, said the estimated 1,500 commercial vessels idled by war are likely now coated with marine microbes, algae and invertebrates.

The ships have sat submerged in the same waters for months, creating idle conditions for what the scientists call “biofouling.”

The scientists are now worried about what could happen when these ships eventually resume their journeys around the world. The study cites “the high likelihood” that the vessels will speed the spread of “economically and ecologically damaging invasive species.”

The threats posed by stranded ships are well-known and long-documented... (MORE - details)]]> https://www.scivillage.com/thread-20951.html Mon, 27 Jul 2026 18:11:11 +0000 C C]]> https://www.scivillage.com/thread-20951.html https://astrobiology.com/2026/07/27/venu...r-from-it/

EXCERPTS: Simulations conducted by researchers at ETH Zurich suggest a strong likelihood that Venus’s rift valleys are still geologically active rather than being mere relics of a bygone era, as had been previously believed. This finding reshapes our understanding of Earth’s sister planet and will influence future missions to Venus.

Venus is an inhospitable place, with temperatures soaring to several hundred degrees Celsius and no oceans like those on Earth. Planetary scientists long believed Venus was geologically dormant. However, recent research indicates that Venus remains geologically “alive” and even hosts active volcanoes.

Rift valleys, which indicate tectonic activity, can be vast and resemble those on Earth, such as the African Rift Valley. On Venus, they can span up to 10,000 kilometres.

The timing of these rifts’ formation is uncertain. Geoscientists believe they originated more than 100 million years ago and are therefore remnants of the past.

[...] The models indicate that broad ridges, known as rift flanks, form along the edges of rift valleys when the rifts are geologically young and either still actively moving or have only recently stopped moving. The simulations also suggest that these rifts widen more rapidly than had been previously believed, at a rate of 3 to 10 centimetres per year.

Yang and his colleagues also show that the rift flanks tend to flatten rapidly after movement ceases; the older the rift system, the less steep and narrow its flanks. Unlike Earth, where erosion gradually wears down features, Venus’s flanks subside due to crustal relaxation.

Wide and high rift flanks are not only produced by the computer model but can also be seen in images of the Venusian surface from the Magellan probe during its 1990’s mission.

Based on their simulations and observational data, the researchers conclude that Venus remains an active planet with a more dynamic interior than had been previously believed. “The results help us to better assess the tectonic activity on Venus,” says Gerya.

The results of the ETH researchers’ model could help pinpoint active regions worthy of detailed investigation for these missions. Additionally, the study enhances our understanding of how rocky planets form. Importantly, the researchers aim to uncover clues that could improve the detection of rocky exoplanets... (MORE - missing details)]]> https://astrobiology.com/2026/07/27/venu...r-from-it/

EXCERPTS: Simulations conducted by researchers at ETH Zurich suggest a strong likelihood that Venus’s rift valleys are still geologically active rather than being mere relics of a bygone era, as had been previously believed. This finding reshapes our understanding of Earth’s sister planet and will influence future missions to Venus.

Venus is an inhospitable place, with temperatures soaring to several hundred degrees Celsius and no oceans like those on Earth. Planetary scientists long believed Venus was geologically dormant. However, recent research indicates that Venus remains geologically “alive” and even hosts active volcanoes.

Rift valleys, which indicate tectonic activity, can be vast and resemble those on Earth, such as the African Rift Valley. On Venus, they can span up to 10,000 kilometres.

The timing of these rifts’ formation is uncertain. Geoscientists believe they originated more than 100 million years ago and are therefore remnants of the past.

[...] The models indicate that broad ridges, known as rift flanks, form along the edges of rift valleys when the rifts are geologically young and either still actively moving or have only recently stopped moving. The simulations also suggest that these rifts widen more rapidly than had been previously believed, at a rate of 3 to 10 centimetres per year.

Yang and his colleagues also show that the rift flanks tend to flatten rapidly after movement ceases; the older the rift system, the less steep and narrow its flanks. Unlike Earth, where erosion gradually wears down features, Venus’s flanks subside due to crustal relaxation.

Wide and high rift flanks are not only produced by the computer model but can also be seen in images of the Venusian surface from the Magellan probe during its 1990’s mission.

Based on their simulations and observational data, the researchers conclude that Venus remains an active planet with a more dynamic interior than had been previously believed. “The results help us to better assess the tectonic activity on Venus,” says Gerya.

The results of the ETH researchers’ model could help pinpoint active regions worthy of detailed investigation for these missions. Additionally, the study enhances our understanding of how rocky planets form. Importantly, the researchers aim to uncover clues that could improve the detection of rocky exoplanets... (MORE - missing details)]]> https://www.scivillage.com/thread-20913.html Tue, 21 Jul 2026 16:15:39 +0000 C C]]> https://www.scivillage.com/thread-20913.html https://gizmodo.com/earths-oceans-are-ra...2000787781

INTRO: Oxygen, the element that sustains nearly all multicellular life on Earth, is disappearing from the world’s aquatic ecosystems. In a new review, scientists warn that this rapidly escalating, human-driven crisis threatens to upend the biosphere.

The paper, published June 30 in the journal Limnology and Oceanography, argues that aquatic deoxygenation should be added to the Planetary Boundaries framework. First introduced by a group of 28 internationally renowned scientists in 2009, the framework identifies nine ways that humanity is pushing crucial processes that maintain Earth’s stability and resilience past their limits. They are climate change, ocean acidification, biodiversity loss, atmospheric aerosol loading, stratospheric ozone depletion, freshwater change, land-use change, chemical pollution, and biogeochemical flows.

“The health and stability of our planet depends on the health and stability of aquatic ecosystems, which need oxygen to function normally,” lead author Erica Ferrer, a postdoctoral scholar at the University of California, Santa Barbara’s National Center for Ecological Analysis and Synthesis, said in a statement. “This study is designed to elevate the profile of aquatic deoxygenation as a global threat and show that it does not operate in isolation.” (MORE - dtails)]]> https://gizmodo.com/earths-oceans-are-ra...2000787781

INTRO: Oxygen, the element that sustains nearly all multicellular life on Earth, is disappearing from the world’s aquatic ecosystems. In a new review, scientists warn that this rapidly escalating, human-driven crisis threatens to upend the biosphere.

The paper, published June 30 in the journal Limnology and Oceanography, argues that aquatic deoxygenation should be added to the Planetary Boundaries framework. First introduced by a group of 28 internationally renowned scientists in 2009, the framework identifies nine ways that humanity is pushing crucial processes that maintain Earth’s stability and resilience past their limits. They are climate change, ocean acidification, biodiversity loss, atmospheric aerosol loading, stratospheric ozone depletion, freshwater change, land-use change, chemical pollution, and biogeochemical flows.

“The health and stability of our planet depends on the health and stability of aquatic ecosystems, which need oxygen to function normally,” lead author Erica Ferrer, a postdoctoral scholar at the University of California, Santa Barbara’s National Center for Ecological Analysis and Synthesis, said in a statement. “This study is designed to elevate the profile of aquatic deoxygenation as a global threat and show that it does not operate in isolation.” (MORE - dtails)]]> https://www.scivillage.com/thread-20871.html Fri, 17 Jul 2026 01:10:45 +0000 C C]]> https://www.scivillage.com/thread-20871.html https://www.seti.org/news/alien-world-ch...meteorite/

KEY POINTS: A meteorite crashed through the roof of a Hillsborough, New Jersey home on July 16, 2024. The meteorite, named Hillsborough, is only the second observed fall of a rare primitive CM1/2 carbonaceous chondrite, making it one of the most scientifically valuable meteorites ever recovered.

The meteorite's pristine condition, preserved by the homeowner immediately after impact, allowed scientists to study fragile minerals and organic compounds rarely seen in recovered meteorites. Researchers found preserved bits from near the surface of the original asteroid where it experienced concentrated salty fluids—a process not previously known from this type of asteroid.

Hillsborough contains a diverse suite of carbon-bearing compounds, amino acids, and other prebiotic molecules that help scientists understand what building blocks of life may have been delivered to the early Earth. The findings provide new insight into the role of water, brines, and asteroid chemistry in shaping the organic inventory of the early solar system.

The international research team's results are published in Science Advances...... (MORE - details)]]> https://www.seti.org/news/alien-world-ch...meteorite/

KEY POINTS: A meteorite crashed through the roof of a Hillsborough, New Jersey home on July 16, 2024. The meteorite, named Hillsborough, is only the second observed fall of a rare primitive CM1/2 carbonaceous chondrite, making it one of the most scientifically valuable meteorites ever recovered.

The meteorite's pristine condition, preserved by the homeowner immediately after impact, allowed scientists to study fragile minerals and organic compounds rarely seen in recovered meteorites. Researchers found preserved bits from near the surface of the original asteroid where it experienced concentrated salty fluids—a process not previously known from this type of asteroid.

Hillsborough contains a diverse suite of carbon-bearing compounds, amino acids, and other prebiotic molecules that help scientists understand what building blocks of life may have been delivered to the early Earth. The findings provide new insight into the role of water, brines, and asteroid chemistry in shaping the organic inventory of the early solar system.

The international research team's results are published in Science Advances...... (MORE - details)]]> https://www.scivillage.com/thread-20802.html Mon, 06 Jul 2026 15:33:04 +0000 C C]]> https://www.scivillage.com/thread-20802.html https://arstechnica.com/science/2026/07/...rst-crust/

INTRO: Earth is the only planet we know of with buoyant, silica-rich continents. But, despite decades of research, geologists still don’t agree on how they formed. “The continents started appearing around about four billion years ago—that’s the oldest continental rock we know about,” said Tim Johnson, a geologist at Curtin University in Perth, Australia. “The Earth is four and a half billion years old, so why they started appearing then is unknown, as is the mechanism to make that continental crust.”

Johnson and his colleagues are now arguing that the formation of continents on Earth was caused largely by an intense, sustained barrage of asteroid impacts that kept the early crust hot and thin enough to make buoyant continents possible. In short, the lands we live on are here because of ancient bombardment from space.

The problem with studying the formation of continents is that the geological evidence of this process is almost gone. The oldest known continental-type rocks crystallized around 4.03 billion years ago, right at the end of the Hadean eon (the earliest era in Earth’s history, spanning the first 500 million years of its existence). Rare basaltic rocks date back about 4.2 billion years, and a handful of the oldest zircon crystals push the record back to 4.4 billion years. Beyond that, there’s hardly anything else. So, scientists looking into the origin of continents had to rely largely on educated guesses. “There are huge debates about what was going on in the early Earth, because the data is so scarce,” Johnson said.

One dominant idea holds that plate tectonics, much like today’s, was already running in the Hadean, with continental crust forming above subduction zones—areas where tectonic plates collide. The other claims that early Earth was too hot for rigid plates, and that crust instead formed above mantle plumes rising from deep within the planet, a phenomenon comparable, Johnson said, to the wax blobs rising inside a lava lamp.

The issue with both these ideas, though, was that Earth, based on most models, appeared too cold for all this to happen. “People have tried to understand Earth’s heat budget through time, and nobody could make it fit,” Johnson said. “Nobody could make it fit because we did not consider the energy coming from outside of Earth.” This energy, he argues, came from asteroid and meteorite impacts that were far more frequent back when the solar system was young. Adding these impacts to the early Earth’s heat budget, though, proved rather challenging because Earth has a peculiar way of healing its scars.

The reason we don’t really know what was happening on Earth four billion years ago is that plate tectonics effectively recycles the surface of the planet back into the mantle. “One place where we do know what was going on back then is the Moon,” Johnson said. “We have sent people there. We have collected sample from there. We have immense amounts of high-quality data from the Moon.” Because the Moon does not have plate tectonics, its crust is a single, solid, continuous shell. And this shell, Johnson’s team noted, is peppered with impact craters.

Calibrated against dated lunar samples, crater counts on the Moon let Johnson’s team estimate how frequently large bodies were hitting our closest celestial neighbor shortly after the Earth had formed... (MORE - details)

PAPER: http://dx.doi.org/10.1126/science.aeb5402]]> https://arstechnica.com/science/2026/07/...rst-crust/

INTRO: Earth is the only planet we know of with buoyant, silica-rich continents. But, despite decades of research, geologists still don’t agree on how they formed. “The continents started appearing around about four billion years ago—that’s the oldest continental rock we know about,” said Tim Johnson, a geologist at Curtin University in Perth, Australia. “The Earth is four and a half billion years old, so why they started appearing then is unknown, as is the mechanism to make that continental crust.”

Johnson and his colleagues are now arguing that the formation of continents on Earth was caused largely by an intense, sustained barrage of asteroid impacts that kept the early crust hot and thin enough to make buoyant continents possible. In short, the lands we live on are here because of ancient bombardment from space.

The problem with studying the formation of continents is that the geological evidence of this process is almost gone. The oldest known continental-type rocks crystallized around 4.03 billion years ago, right at the end of the Hadean eon (the earliest era in Earth’s history, spanning the first 500 million years of its existence). Rare basaltic rocks date back about 4.2 billion years, and a handful of the oldest zircon crystals push the record back to 4.4 billion years. Beyond that, there’s hardly anything else. So, scientists looking into the origin of continents had to rely largely on educated guesses. “There are huge debates about what was going on in the early Earth, because the data is so scarce,” Johnson said.

One dominant idea holds that plate tectonics, much like today’s, was already running in the Hadean, with continental crust forming above subduction zones—areas where tectonic plates collide. The other claims that early Earth was too hot for rigid plates, and that crust instead formed above mantle plumes rising from deep within the planet, a phenomenon comparable, Johnson said, to the wax blobs rising inside a lava lamp.

The issue with both these ideas, though, was that Earth, based on most models, appeared too cold for all this to happen. “People have tried to understand Earth’s heat budget through time, and nobody could make it fit,” Johnson said. “Nobody could make it fit because we did not consider the energy coming from outside of Earth.” This energy, he argues, came from asteroid and meteorite impacts that were far more frequent back when the solar system was young. Adding these impacts to the early Earth’s heat budget, though, proved rather challenging because Earth has a peculiar way of healing its scars.

The reason we don’t really know what was happening on Earth four billion years ago is that plate tectonics effectively recycles the surface of the planet back into the mantle. “One place where we do know what was going on back then is the Moon,” Johnson said. “We have sent people there. We have collected sample from there. We have immense amounts of high-quality data from the Moon.” Because the Moon does not have plate tectonics, its crust is a single, solid, continuous shell. And this shell, Johnson’s team noted, is peppered with impact craters.

Calibrated against dated lunar samples, crater counts on the Moon let Johnson’s team estimate how frequently large bodies were hitting our closest celestial neighbor shortly after the Earth had formed... (MORE - details)

PAPER: http://dx.doi.org/10.1126/science.aeb5402]]> https://www.scivillage.com/thread-20659.html Wed, 17 Jun 2026 16:46:45 +0000 C C]]> https://www.scivillage.com/thread-20659.html https://aeon.co/essays/the-strange-rocks...without-us

EXCERPTS: As a geologist, I have studied various types of natural rocks, but recently I have become interested in ‘anthropogenic geomaterials’ – things like industrial slag – and how they become entwined in geological and environmental processes. I came to Workington originally to look at the slag...

[...] For geologists who study rock day in day out, it’s such a foundational concept that we rarely stop to ask what’s the actual definition of a rock. So I quizzed a few, in a non-statistical, non-exhaustive informal survey of geological friends and colleagues. When asked, hardness featured heavily in people’s definitions, and most agreed that a rock is a substance made of minerals. There was less agreement with the dictionary when it came to size though – the OED and Cambridge definitions point to rock being a large mass or even the whole Earth, but some geologists would argue that a grain of sand could be considered a rock. It is, after all, hard and made of minerals, like quartz or feldspar.

Perhaps the most debated part of the definition, and the one most relevant to this essay, is whether a rock must be natural. The overwhelming majority of rocks on Earth form through natural geological processes such as solidification of molten lava flows, or compression and compaction deep within the Earth. However, everyday materials created by humans such as pottery, concrete or bricks are made of minerals. Are these rocks? Many would say not. Perhaps that’s because these materials are processed, manufactured, and more often found in the built environment rather than in wild landscapes. As we discovered at Workington, though, the border between natural and human is more difficult to draw.

If you were to tell anybody about a pile of thousands of tonnes of industrial waste, most people’s reaction would probably be to recoil in disgust. In many cases this holds true, such as when old landfills of municipal waste are exposed through coastal erosion, resulting in old rags, sanitary products and medical waste leaking onto coastlines. There’s something about a wet muddy bit of fabric on the beach that just gives you the ‘ick’. However, the vast majority of visitors to a place such as Workington would be none the wiser that they were in the proximity of a huge volume of industrial waste.

[...] Human beings have created slag for thousands of years, ever since people started working with metals. While in the past it was simply dumped, today the material is often reused in other settings, such as cement production, road construction, agriculture, or along railway lines as ballast.

[...] Once the slag that makes the cliff was poured and solidified, human involvement in the story ends. Workington is quite an exposed coast, with storms rolling in over the Irish Sea. The waves crashing against the slag cliffs causes them to erode – just like natural coastal cliffs – chipping off small, angular pebble-sized pieces. The wave and tide action then rounds off the corners.

[...] Anthropogenic rock formation is a frontier research area with relatively few examples documented. However, once we understood what was going on at Workington, we were able to identify the same process occurring in other places where iron and steel slag had been dumped historically, with examples in northern England and southwest Scotland. We also started to find evidence of ‘rocks’ forming from other human-made materials, or where human processes had been key.

[...] Geologists are also learning that the more ‘solid’ examples of industrial waste can actually bring many benefits. Slag has carbon dioxide mineralising properties – essentially scrubbing CO2 out of the atmosphere, giving it the opportunity to help us in our fight against anthropogenic climate change. Additionally, old slag banks are known to be havens for rare species of plants and invertebrates – their gravelly and alkaline nature makes them an unusual habitat. However, if the gravelly slag has fused together into a rock, it may be more difficult for ecological colonisation. The study of such anthropogenic materials is a frontier area of research and there remain many unknowns.

In our discipline, we geologists are used to looking back into the distant past, perhaps to learn lessons about what our geological future might look like. With these anthropogenic rocks it is difficult to do this, as no ancient analogues exist... (MORE - missing details)]]> https://aeon.co/essays/the-strange-rocks...without-us

EXCERPTS: As a geologist, I have studied various types of natural rocks, but recently I have become interested in ‘anthropogenic geomaterials’ – things like industrial slag – and how they become entwined in geological and environmental processes. I came to Workington originally to look at the slag...

[...] For geologists who study rock day in day out, it’s such a foundational concept that we rarely stop to ask what’s the actual definition of a rock. So I quizzed a few, in a non-statistical, non-exhaustive informal survey of geological friends and colleagues. When asked, hardness featured heavily in people’s definitions, and most agreed that a rock is a substance made of minerals. There was less agreement with the dictionary when it came to size though – the OED and Cambridge definitions point to rock being a large mass or even the whole Earth, but some geologists would argue that a grain of sand could be considered a rock. It is, after all, hard and made of minerals, like quartz or feldspar.

Perhaps the most debated part of the definition, and the one most relevant to this essay, is whether a rock must be natural. The overwhelming majority of rocks on Earth form through natural geological processes such as solidification of molten lava flows, or compression and compaction deep within the Earth. However, everyday materials created by humans such as pottery, concrete or bricks are made of minerals. Are these rocks? Many would say not. Perhaps that’s because these materials are processed, manufactured, and more often found in the built environment rather than in wild landscapes. As we discovered at Workington, though, the border between natural and human is more difficult to draw.

If you were to tell anybody about a pile of thousands of tonnes of industrial waste, most people’s reaction would probably be to recoil in disgust. In many cases this holds true, such as when old landfills of municipal waste are exposed through coastal erosion, resulting in old rags, sanitary products and medical waste leaking onto coastlines. There’s something about a wet muddy bit of fabric on the beach that just gives you the ‘ick’. However, the vast majority of visitors to a place such as Workington would be none the wiser that they were in the proximity of a huge volume of industrial waste.

[...] Human beings have created slag for thousands of years, ever since people started working with metals. While in the past it was simply dumped, today the material is often reused in other settings, such as cement production, road construction, agriculture, or along railway lines as ballast.

[...] Once the slag that makes the cliff was poured and solidified, human involvement in the story ends. Workington is quite an exposed coast, with storms rolling in over the Irish Sea. The waves crashing against the slag cliffs causes them to erode – just like natural coastal cliffs – chipping off small, angular pebble-sized pieces. The wave and tide action then rounds off the corners.

[...] Anthropogenic rock formation is a frontier research area with relatively few examples documented. However, once we understood what was going on at Workington, we were able to identify the same process occurring in other places where iron and steel slag had been dumped historically, with examples in northern England and southwest Scotland. We also started to find evidence of ‘rocks’ forming from other human-made materials, or where human processes had been key.

[...] Geologists are also learning that the more ‘solid’ examples of industrial waste can actually bring many benefits. Slag has carbon dioxide mineralising properties – essentially scrubbing CO2 out of the atmosphere, giving it the opportunity to help us in our fight against anthropogenic climate change. Additionally, old slag banks are known to be havens for rare species of plants and invertebrates – their gravelly and alkaline nature makes them an unusual habitat. However, if the gravelly slag has fused together into a rock, it may be more difficult for ecological colonisation. The study of such anthropogenic materials is a frontier area of research and there remain many unknowns.

In our discipline, we geologists are used to looking back into the distant past, perhaps to learn lessons about what our geological future might look like. With these anthropogenic rocks it is difficult to do this, as no ancient analogues exist... (MORE - missing details)]]> https://www.scivillage.com/thread-20650.html Tue, 16 Jun 2026 20:07:41 +0000 C C]]> https://www.scivillage.com/thread-20650.html https://arstechnica.com/science/2026/06/...-on-earth/

EXCERPT: The, uh, good news about these estimates for the demise of complex life on Earth is that they’re actually a bit more optimistic than most previous studies. That’s down to the 3D model producing a little less warming for a brighter Sun, the expectation that CO2 declines more slowly over time, and a slight expansion of the CO2 range believed to be survivable by plants. Many previous estimates had put life’s expiration date at less than 1 billion years from now.

Obviously, there are a bunch of additional considerations that could significantly alter this story, and the researchers mention a few. If civilization persists long enough to see some of these changes, geoengineering would certainly be an option—like spreading aerosols in the stratosphere to reflect sunlight, for example.

There are even some wilder suggestions out there, like moving Earth’s orbit farther from the Sun or removing some of the Sun’s mass to tame the red giant. (We have a billion years to work on the logistics, after all.)

Less speculatively, evolution could have a say in the physiological limits of Earth’s plants. Any adaptations that expand the range of survivability would extend the timeline.

Ultimately, the point of modeling this kind of thing is not to make a confident prediction. Apart from the simple natural curiosity about what will happen to our world, this is also relevant to wondering about the potential for life on other worlds. The window of time during which life on Earth is possible tells us something about where to look outside our Solar System.

Land plants have been present on Earth for almost 500 million years, and if this new estimate is right, they could stick around for almost 1.9 billion more. As was the case for a few billion years early on, microbial life might again have the place to themselves for a while after that... (MORE - missing detail)

PAPER: http://dx.doi.org/10.1029/2025JD045586]]> https://arstechnica.com/science/2026/06/...-on-earth/

EXCERPT: The, uh, good news about these estimates for the demise of complex life on Earth is that they’re actually a bit more optimistic than most previous studies. That’s down to the 3D model producing a little less warming for a brighter Sun, the expectation that CO2 declines more slowly over time, and a slight expansion of the CO2 range believed to be survivable by plants. Many previous estimates had put life’s expiration date at less than 1 billion years from now.

Obviously, there are a bunch of additional considerations that could significantly alter this story, and the researchers mention a few. If civilization persists long enough to see some of these changes, geoengineering would certainly be an option—like spreading aerosols in the stratosphere to reflect sunlight, for example.

There are even some wilder suggestions out there, like moving Earth’s orbit farther from the Sun or removing some of the Sun’s mass to tame the red giant. (We have a billion years to work on the logistics, after all.)

Less speculatively, evolution could have a say in the physiological limits of Earth’s plants. Any adaptations that expand the range of survivability would extend the timeline.

Ultimately, the point of modeling this kind of thing is not to make a confident prediction. Apart from the simple natural curiosity about what will happen to our world, this is also relevant to wondering about the potential for life on other worlds. The window of time during which life on Earth is possible tells us something about where to look outside our Solar System.

Land plants have been present on Earth for almost 500 million years, and if this new estimate is right, they could stick around for almost 1.9 billion more. As was the case for a few billion years early on, microbial life might again have the place to themselves for a while after that... (MORE - missing detail)

PAPER: http://dx.doi.org/10.1029/2025JD045586]]> https://www.scivillage.com/thread-20553.html Mon, 01 Jun 2026 13:25:37 +0000 PLCoulomb]]> https://www.scivillage.com/thread-20553.html https://earthquake.usgs.gov/earthquakes/.../executive

I keep an eye on unusual seismic readings and this one caught my attention.  From the perspective of two seismographs, I noticed that waves associated with this temblor were time-compressed into a sharp, punctuated burst of activity, but the same waves were spread out evenly as one might expect as measured from other stations.  The two nearest stations, one in Nevada and one in Columbia, CA show this compression.

It's my hypothesis that fluids of tapered density can cause sound and heat to become compressed as they are conveyed over distance.  Magma, for example, if under extreme pressure in one area might gradually release its pressure, resulting in a pressure gradient which causes seismic waves to travel at variable speeds through the liquid, causing seismic waves emitted at a latter point in time to be able to catch up with the initial waves, causing compression over time.  If that's what's occurring here, it could indicate that a dormant volcano in the High Sierras and, more specifically, in the South Mono area is getting ready to go active.  These are rarely active, but if they were to become active again, it could be a disaster for the people in the area.

The waves are being compressed as a result of density gradually decreasing over the distance from the epicenter of this foreshock toward the detector.  Mono Lake, Lee Vining and Yosemite could become volcanically active based upon these readings, but the USGS quite frankly doesn't know what it's doing.  It's something to watch.]]> https://earthquake.usgs.gov/earthquakes/.../executive

I keep an eye on unusual seismic readings and this one caught my attention.  From the perspective of two seismographs, I noticed that waves associated with this temblor were time-compressed into a sharp, punctuated burst of activity, but the same waves were spread out evenly as one might expect as measured from other stations.  The two nearest stations, one in Nevada and one in Columbia, CA show this compression.

It's my hypothesis that fluids of tapered density can cause sound and heat to become compressed as they are conveyed over distance.  Magma, for example, if under extreme pressure in one area might gradually release its pressure, resulting in a pressure gradient which causes seismic waves to travel at variable speeds through the liquid, causing seismic waves emitted at a latter point in time to be able to catch up with the initial waves, causing compression over time.  If that's what's occurring here, it could indicate that a dormant volcano in the High Sierras and, more specifically, in the South Mono area is getting ready to go active.  These are rarely active, but if they were to become active again, it could be a disaster for the people in the area.

The waves are being compressed as a result of density gradually decreasing over the distance from the epicenter of this foreshock toward the detector.  Mono Lake, Lee Vining and Yosemite could become volcanically active based upon these readings, but the USGS quite frankly doesn't know what it's doing.  It's something to watch.]]> https://www.scivillage.com/thread-20540.html Fri, 29 May 2026 06:53:35 +0000 C C]]> https://www.scivillage.com/thread-20540.html https://www.eurekalert.org/news-releases/1130210

INTRO: One of the most devastating extinctions in Earth’s history is best known for what didn’t die — dinosaurs. But the end-Triassic extinction 201 million years ago wiped out roughly 60 percent of Earth’s species, and scientists are still piecing together how it unfolded.

New evidence from Virginia Tech geologists shows that the volcanic eruptions that ripped apart the land and acidified the oceans also stripped the oxygen out of their waters. And, in an unexpected finding, the research team discovered that oxygen starvation began nearly 8 million years before the mass extinction.

Their study was published May 26 in Nature Communications Earth & Environment... (MORE - no ads)]]> https://www.eurekalert.org/news-releases/1130210

INTRO: One of the most devastating extinctions in Earth’s history is best known for what didn’t die — dinosaurs. But the end-Triassic extinction 201 million years ago wiped out roughly 60 percent of Earth’s species, and scientists are still piecing together how it unfolded.

New evidence from Virginia Tech geologists shows that the volcanic eruptions that ripped apart the land and acidified the oceans also stripped the oxygen out of their waters. And, in an unexpected finding, the research team discovered that oxygen starvation began nearly 8 million years before the mass extinction.

Their study was published May 26 in Nature Communications Earth & Environment... (MORE - no ads)]]> https://www.scivillage.com/thread-20470.html Tue, 19 May 2026 15:53:41 +0000 C C]]> https://www.scivillage.com/thread-20470.html https://www.eurekalert.org/news-releases/1128508

INTRO: Looking back at 14 years of Hubble telescope data for Jupiter’s moon Europa has given Southwest Research Institute (SwRI) scientists a better understanding of its tenuous atmosphere. The findings have cast doubt on previous evidence suggesting that the icy moon intermittently discharges faint water plumes from a presumed subsurface ocean.

“The evidence for water vapor plumes on Europa isn’t as strong as we first understood it,” said SwRI’s Dr. Kurt Retherford, one of the authors of a 2014 paper initially making that assertion. Retherford and his colleagues have recently published a new paper reanalyzing the data.

The new paper looks at the last 14 years of data from the Hubble Space Telescope’s Space Telescope Imaging Spectrograph (HST/STIS) focused on Europa’s Lyman-alpha emissions. Lyman-alpha is a specific wavelength of ultraviolet light emitted and scattered by hydrogen atoms. From 2012-2014, the team was pushing the limits of the Hubble telescope’s capabilities.

“One of the difficulties in interpreting the data back then was determining where to place Europa within its context,” Retherford said. “The way Hubble works left some uncertainty in terms of placement relative to the center of the image. If Europa’s placement was off even just by a pixel or two, it could affect how the data gets interpreted.”

As a result, what they thought could be evidence of a water vapor plume could also just be statistical noise... (MORE - no ads)]]> https://www.eurekalert.org/news-releases/1128508

INTRO: Looking back at 14 years of Hubble telescope data for Jupiter’s moon Europa has given Southwest Research Institute (SwRI) scientists a better understanding of its tenuous atmosphere. The findings have cast doubt on previous evidence suggesting that the icy moon intermittently discharges faint water plumes from a presumed subsurface ocean.

“The evidence for water vapor plumes on Europa isn’t as strong as we first understood it,” said SwRI’s Dr. Kurt Retherford, one of the authors of a 2014 paper initially making that assertion. Retherford and his colleagues have recently published a new paper reanalyzing the data.

The new paper looks at the last 14 years of data from the Hubble Space Telescope’s Space Telescope Imaging Spectrograph (HST/STIS) focused on Europa’s Lyman-alpha emissions. Lyman-alpha is a specific wavelength of ultraviolet light emitted and scattered by hydrogen atoms. From 2012-2014, the team was pushing the limits of the Hubble telescope’s capabilities.

“One of the difficulties in interpreting the data back then was determining where to place Europa within its context,” Retherford said. “The way Hubble works left some uncertainty in terms of placement relative to the center of the image. If Europa’s placement was off even just by a pixel or two, it could affect how the data gets interpreted.”

As a result, what they thought could be evidence of a water vapor plume could also just be statistical noise... (MORE - no ads)]]> https://www.scivillage.com/thread-20406.html Mon, 11 May 2026 14:14:42 +0000 C C]]> https://www.scivillage.com/thread-20406.html https://seas.harvard.edu/news/new-explan...ball-earth

PRESS RELEASE: A new study by Earth scientists in the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) offers an explanation for one of Earth’s great climate puzzles: how the Sturtian glaciation, an ancient ice age when the planet was nearly entirely frozen, could have lasted 56 million years – far longer than standard climate models have predicted. This lengthy freeze took place during Earth’s Cryogenian period, roughly 717 to 660 million years ago, predating dinosaurs and complex plant life.

The research is published in Proceedings of the National Academy of Sciences and led by graduate student Charlotte Minsky, who is advised by co-author Robin Wordsworth, the Gordon McKay Professor of Environmental Science and Engineering and Professor of Earth and Planetary Sciences. Co-authors are David T. Johnston and Andrew H. Knoll.

Using a coupled model of the ancient climate and the global carbon cycle, the researchers make the case that Earth may not have been locked in a single, unbroken “Snowball Earth” state, or period when the entire planet was frozen. Instead, they find that the planet likely oscillated between fully ice-covered “snowball” conditions and ice-free “hothouse” intervals throughout the Sturtian period.

The team’s simulations suggest that intense weathering of basalt in the Franklin Large Igneous Province, a vast volcanic region located in northern Canada and believed to have erupted just before the onset of the Sturtian glaciation, drew down atmospheric carbon dioxide enough to trigger multiple global glaciations.

As volcanoes and other processes slowly rebuilt atmospheric carbon dioxide, the climate warmed, the ice retreated, and large areas of fresh basalt were again exposed to the atmosphere. Renewed breakdown from weathering then pulled carbon dioxide back down, pushing the climate into another Snowball phase. This repeating cycle of carbon dioxide-driven freezing and thawing, the authors argue, could naturally sustain glacial–interglacial swings over tens of millions of years.

The mechanisms revealed by the Harvard study resolve several longstanding paradoxes, most notably the previously inexplicable length of the Sturtian when compared with physical climate models. The study also matches observed sedimentary patterns from that time period and explains how atmospheric oxygen levels could have remained stable despite extreme climate upheavals.

Repeated returns to warmer, ice-free conditions may have helped prevent a complete collapse of atmospheric oxygen, the study further suggests. “This could help explain how aerobic life persisted through such an extreme interval,” Minsky said.

Learn more: "Repeated Snowball-hothouse cycles within the Neoproterozoic Sturtian glaciation."]]> https://seas.harvard.edu/news/new-explan...ball-earth

PRESS RELEASE: A new study by Earth scientists in the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) offers an explanation for one of Earth’s great climate puzzles: how the Sturtian glaciation, an ancient ice age when the planet was nearly entirely frozen, could have lasted 56 million years – far longer than standard climate models have predicted. This lengthy freeze took place during Earth’s Cryogenian period, roughly 717 to 660 million years ago, predating dinosaurs and complex plant life.

The research is published in Proceedings of the National Academy of Sciences and led by graduate student Charlotte Minsky, who is advised by co-author Robin Wordsworth, the Gordon McKay Professor of Environmental Science and Engineering and Professor of Earth and Planetary Sciences. Co-authors are David T. Johnston and Andrew H. Knoll.

Using a coupled model of the ancient climate and the global carbon cycle, the researchers make the case that Earth may not have been locked in a single, unbroken “Snowball Earth” state, or period when the entire planet was frozen. Instead, they find that the planet likely oscillated between fully ice-covered “snowball” conditions and ice-free “hothouse” intervals throughout the Sturtian period.

The team’s simulations suggest that intense weathering of basalt in the Franklin Large Igneous Province, a vast volcanic region located in northern Canada and believed to have erupted just before the onset of the Sturtian glaciation, drew down atmospheric carbon dioxide enough to trigger multiple global glaciations.

As volcanoes and other processes slowly rebuilt atmospheric carbon dioxide, the climate warmed, the ice retreated, and large areas of fresh basalt were again exposed to the atmosphere. Renewed breakdown from weathering then pulled carbon dioxide back down, pushing the climate into another Snowball phase. This repeating cycle of carbon dioxide-driven freezing and thawing, the authors argue, could naturally sustain glacial–interglacial swings over tens of millions of years.

The mechanisms revealed by the Harvard study resolve several longstanding paradoxes, most notably the previously inexplicable length of the Sturtian when compared with physical climate models. The study also matches observed sedimentary patterns from that time period and explains how atmospheric oxygen levels could have remained stable despite extreme climate upheavals.

Repeated returns to warmer, ice-free conditions may have helped prevent a complete collapse of atmospheric oxygen, the study further suggests. “This could help explain how aerobic life persisted through such an extreme interval,” Minsky said.

Learn more: "Repeated Snowball-hothouse cycles within the Neoproterozoic Sturtian glaciation."]]> https://www.scivillage.com/thread-20359.html Mon, 04 May 2026 16:15:36 +0000 C C]]> https://www.scivillage.com/thread-20359.html https://www.sciencefocus.com/news/amoc-w...we-thought

EXCERPTS: A major ocean current system that helps regulate climate across the Northern Hemisphere is likely to weaken far more severely by the end of this century than scientists previously estimated, according to new research published in Science Advances.

The Atlantic Meridional Overturning Circulation (AMOC) is a vast system of currents that transports warm water from the tropics northward, releasing heat into the atmosphere before sinking and returning south.

[...] Beyond the US, a weakening is projected to shift the tropical rain belt southward, threatening the monsoons that hundreds of millions of people in West Africa and South Asia depend on for agriculture.

In Europe, such changes are projected to bring colder, harsher winters as the conveyor belt of warm water to the continent slows.

More concerning still is that each additional weakening pushes the system closer to a tipping point – where a full collapse becomes increasingly likely, with consequences that could be catastrophic.

[...] In the new study, the team identified two specific, systematic errors running through many of the best modelling efforts made so far: they simulate the South Atlantic as not salty enough and the North Atlantic as too cold.

Both biases cause the models to underestimate a key process, in which dense, salty water sinks and helps keep the entire current system flowing.

After correcting for both using a statistical technique called ridge-regularised linear regression – rarely used in climate science – the projected weakening rose to 51 per cent, while significantly decreasing the uncertainty associated with the result... (MORE - missing details)]]> https://www.sciencefocus.com/news/amoc-w...we-thought

EXCERPTS: A major ocean current system that helps regulate climate across the Northern Hemisphere is likely to weaken far more severely by the end of this century than scientists previously estimated, according to new research published in Science Advances.

The Atlantic Meridional Overturning Circulation (AMOC) is a vast system of currents that transports warm water from the tropics northward, releasing heat into the atmosphere before sinking and returning south.

[...] Beyond the US, a weakening is projected to shift the tropical rain belt southward, threatening the monsoons that hundreds of millions of people in West Africa and South Asia depend on for agriculture.

In Europe, such changes are projected to bring colder, harsher winters as the conveyor belt of warm water to the continent slows.

More concerning still is that each additional weakening pushes the system closer to a tipping point – where a full collapse becomes increasingly likely, with consequences that could be catastrophic.

[...] In the new study, the team identified two specific, systematic errors running through many of the best modelling efforts made so far: they simulate the South Atlantic as not salty enough and the North Atlantic as too cold.

Both biases cause the models to underestimate a key process, in which dense, salty water sinks and helps keep the entire current system flowing.

After correcting for both using a statistical technique called ridge-regularised linear regression – rarely used in climate science – the projected weakening rose to 51 per cent, while significantly decreasing the uncertainty associated with the result... (MORE - missing details)]]> https://www.scivillage.com/thread-20221.html Sat, 18 Apr 2026 21:08:57 +0000 C C]]> https://www.scivillage.com/thread-20221.html Tectonic “pump” may close the evolutionary loop for subseafloor microbes
https://www.eurekalert.org/news-releases/1124649

INTO: In subduction zones, the sites of the world’s largest earthquakes, tectonic activity may generate a “pump” that transports long-buried subseafloor microbes back toward the seafloor, according to research presented at the 2026 SSA Annual Meeting.

These microbes are the world’s most dedicated sleeping beauties, lying dormant for thousands or even millions of years beneath a kilometer-deep blanket of ocean sediment. They survive this prolonged dormancy with the help of a range of specialized adaptations.

But to pass on these adaptations to the next generation, the microbes must eventually reach the shallowest layers of the seafloor where they can eat, grow and disperse. That’s where the tectonic pump comes in, said Zhengze Li, a Ph.D. student at the University of Southern California.

Li and his colleagues suggest that fault slip in subduction zones drives fluid flow that transports long-buried subsurface microbes back toward the seafloor. According to their models, this tectonic pump could circulate more than 1 million gigatons of fluid per million years, potentially transporting up to 1030 microbial cells.

At the meeting, Li explained how this microbial “elevator” might work. In subduction zones, where one tectonic plate descends beneath another, layers of sediment on the downgoing plate are scraped off and accumulate in a wedge against the overriding plate.

Some of the deep, dormant microbes remain on the downgoing plate and continue their descent beneath the overriding plate toward the mantle, a journey Li and his colleagues call “the trip to hell.”

Microbes that avoid that fate, however, may be transported upward through fractures and faults in the sediment wedge, or more diffusely through the sediments, driven by subduction-related slip.

Relocated to the shallow seafloor, the microbes “can now be reactivated and can reproduce,” Li said. “The full cycle—from burial and transport with the subducting plate to eventual return—can take tens of millions of years or longer.” (MORE - no ads)

---

Andes volcanoes – the missing link between algae blooms, whales and climate millions of years ago
https://www.eurekalert.org/news-releases/1124760

INTRO: In 2010, construction workers on the Panamerican Highway traversing Chile's Atacama Desert stumbled upon a nearly perfectly preserved fossilized whale – and once paleontologists rushed to the site to document the ancient treasures in a race against time while the road project was on hold, more were unearthed in quick succession.

Totaling more than 40 specimens – whales, porpoises and other marine mammals – dating from about 6 to 9 million years ago, the site known as Cerro Ballena, or "Whale Hill," is now famously recognized as the world's largest concentration of whale fossils. Paleontologists soon realized the animals perished quickly and in a relatively small area. But why?

As if one mystery wasn't enough, around the same time marine life experienced important changes, whales became bigger and climate data reveal a dramatic shift toward cooler sea surface temperatures. Geologic records from that time, known as the late Miocene, bear witness to intense volcanic eruptions in the wake of tectonic upheaval that led to the building of the Andes mountain range along the western edge of South America.

Now, a study led by researchers at the University of Arizona provides a previously unrecognized piece of the puzzle: The vast amounts of volcanic ashes released into the atmosphere ended up in the ocean, particularly in the Southern Ocean, where they provided a smorgasbord for marine algae to feast on. Volcanic ash is known to contain important nutrients, including phosphorus, iron and silicon. A significant increase in volcanic activity in the Andes peaking between eight and four million years ago, therefore, likely delivered a significant pulse of nutrients – especially iron – to the Southern Ocean.

This induced a chain reaction driving environmental changes by increasing productivity among primary producers – organisms that consume carbon dioxide and use sunlight to create their own food and energy. Increased productivity also supported larger body size in whales. However, in some localities, like Cerro Ballena, nutrients from Andes volcanoes lead to widespread algal blooms, which released toxins that proved detrimental to any whales in the affected areas. The same algal blooms also would have removed large amounts of carbon dioxide, a powerful greenhouse gas, from the atmosphere, which would have helped cool the planet.

Volcanic eruptions have long been recognized as major sources of carbon dioxide in the atmosphere before humans began burning fossil fuels on an industrial scale, thus driving warming. But the role of volcanism in doing the opposite – cooling down the Earth system – has gone largely unrecognized, said Barbara Carrapa, a professor of geosciences in the University of Arizona College of Science and first author of this study, which is published in the journal Nature Communications Earth & Environment.

"Once you put a lot of very important nutrients coming from volcanoes into the ocean, then your primary producers are going to go crazy, because all of a sudden they have a lot of nutrients available to them, and that, in turn, is going to affect the entire marine ecosystem," she said... (MORE - no ads)]]> Tectonic “pump” may close the evolutionary loop for subseafloor microbes
https://www.eurekalert.org/news-releases/1124649

INTO: In subduction zones, the sites of the world’s largest earthquakes, tectonic activity may generate a “pump” that transports long-buried subseafloor microbes back toward the seafloor, according to research presented at the 2026 SSA Annual Meeting.

These microbes are the world’s most dedicated sleeping beauties, lying dormant for thousands or even millions of years beneath a kilometer-deep blanket of ocean sediment. They survive this prolonged dormancy with the help of a range of specialized adaptations.

But to pass on these adaptations to the next generation, the microbes must eventually reach the shallowest layers of the seafloor where they can eat, grow and disperse. That’s where the tectonic pump comes in, said Zhengze Li, a Ph.D. student at the University of Southern California.

Li and his colleagues suggest that fault slip in subduction zones drives fluid flow that transports long-buried subsurface microbes back toward the seafloor. According to their models, this tectonic pump could circulate more than 1 million gigatons of fluid per million years, potentially transporting up to 1030 microbial cells.

At the meeting, Li explained how this microbial “elevator” might work. In subduction zones, where one tectonic plate descends beneath another, layers of sediment on the downgoing plate are scraped off and accumulate in a wedge against the overriding plate.

Some of the deep, dormant microbes remain on the downgoing plate and continue their descent beneath the overriding plate toward the mantle, a journey Li and his colleagues call “the trip to hell.”

Microbes that avoid that fate, however, may be transported upward through fractures and faults in the sediment wedge, or more diffusely through the sediments, driven by subduction-related slip.

Relocated to the shallow seafloor, the microbes “can now be reactivated and can reproduce,” Li said. “The full cycle—from burial and transport with the subducting plate to eventual return—can take tens of millions of years or longer.” (MORE - no ads)

---

Andes volcanoes – the missing link between algae blooms, whales and climate millions of years ago
https://www.eurekalert.org/news-releases/1124760

INTRO: In 2010, construction workers on the Panamerican Highway traversing Chile's Atacama Desert stumbled upon a nearly perfectly preserved fossilized whale – and once paleontologists rushed to the site to document the ancient treasures in a race against time while the road project was on hold, more were unearthed in quick succession.

Totaling more than 40 specimens – whales, porpoises and other marine mammals – dating from about 6 to 9 million years ago, the site known as Cerro Ballena, or "Whale Hill," is now famously recognized as the world's largest concentration of whale fossils. Paleontologists soon realized the animals perished quickly and in a relatively small area. But why?

As if one mystery wasn't enough, around the same time marine life experienced important changes, whales became bigger and climate data reveal a dramatic shift toward cooler sea surface temperatures. Geologic records from that time, known as the late Miocene, bear witness to intense volcanic eruptions in the wake of tectonic upheaval that led to the building of the Andes mountain range along the western edge of South America.

Now, a study led by researchers at the University of Arizona provides a previously unrecognized piece of the puzzle: The vast amounts of volcanic ashes released into the atmosphere ended up in the ocean, particularly in the Southern Ocean, where they provided a smorgasbord for marine algae to feast on. Volcanic ash is known to contain important nutrients, including phosphorus, iron and silicon. A significant increase in volcanic activity in the Andes peaking between eight and four million years ago, therefore, likely delivered a significant pulse of nutrients – especially iron – to the Southern Ocean.

This induced a chain reaction driving environmental changes by increasing productivity among primary producers – organisms that consume carbon dioxide and use sunlight to create their own food and energy. Increased productivity also supported larger body size in whales. However, in some localities, like Cerro Ballena, nutrients from Andes volcanoes lead to widespread algal blooms, which released toxins that proved detrimental to any whales in the affected areas. The same algal blooms also would have removed large amounts of carbon dioxide, a powerful greenhouse gas, from the atmosphere, which would have helped cool the planet.

Volcanic eruptions have long been recognized as major sources of carbon dioxide in the atmosphere before humans began burning fossil fuels on an industrial scale, thus driving warming. But the role of volcanism in doing the opposite – cooling down the Earth system – has gone largely unrecognized, said Barbara Carrapa, a professor of geosciences in the University of Arizona College of Science and first author of this study, which is published in the journal Nature Communications Earth & Environment.

"Once you put a lot of very important nutrients coming from volcanoes into the ocean, then your primary producers are going to go crazy, because all of a sudden they have a lot of nutrients available to them, and that, in turn, is going to affect the entire marine ecosystem," she said... (MORE - no ads)]]>