Apr 18, 2026 10:08 PM
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)
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)
