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A never-before-seen ecosystem lurks in a subterranean river deep beneath Antarctica’s icy surface. Researchers recently brought this “hidden world” to light, revealing a dark and craggy cavern filled with swarms of tiny shrimp-like creatures.
The scientists found the secret subterranean habitat hidden beneath the Larsen Ice Shelf — a massive, floating sheet of ice attached to the east coast of the Antarctic Peninsula famous for the birth of the Larsen Ice Shelf the largest iceberg in the world in 2021. Satellite photos showed an unusual groove in the ice shelf near where it meets land, and researchers identified the distinctive feature as an underground river, which they described in a expression (opens in new tab). Using a powerful hot water hose, the team drilled about 500 meters below the ice surface to reach the underground chamber.
As the researchers sent a camera down the icy tunnel and into the cave, hundreds of tiny, blurry blobs in the water obscured the video feed. Initially, the team thought their equipment was faulty. But after refocusing the camera, they found tiny crustaceans called amphipods swarming around the lens. This caught the team unprepared as they did not expect to find any kind of life so far below the icy surface.
“Having all these animals swimming around our camera means that there is clearly an important ecosystem process happening there,” Craig Stevens, a physical oceanographer at the National Institute of Water and Atmospheric Research (NIWA) in Auckland, New Zealand, said in the statement. The discovery of the secret shrimp-infested structure had the team “jumping with joy,” Stevens added.
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Experts have long suspected that there is a vast network of rivers, lakes, and estuaries beneath Antarctica, but until now these features have been little studied. It was previously unknown if they harbored life, making the new discovery even more relevant. “Observing and tasting this flow was like being the first to enter a hidden world,” said lead researcher Huw Horgan, a glaciologist at Te Herenga Waka – Victoria University of Wellington in New Zealand The guard (opens in new tab).
Horgan first discovered evidence of the underground structure in 2020 when he looked at a satellite photo of the area. It was visible as a long depression or gully stretching across the ice – a hallmark of an underground river. Though the groove was noticeable in the satellite imagery, it initially eluded surface detection, Stevens said. “But then we found this tiny, gentle slope and figured we’d found the right spot.”
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After the camera was sent down into the river, the team was surprised to find that the cave looked drastically different than predicted. The researchers had expected the roof of the chamber to be smooth and flat. Instead, they found that the roof was very uneven and had many steep ripples. The cave was also much wider near the roof. “It looked like a loaf of bread, with a bulge at the top and a narrow slope at the bottom,” Stevens said.
The researchers also unexpectedly discovered that the underground water column split into four or five different layers of water that flowed in opposite directions. “This changes our current understanding and models of these environments,” Stevens said. “We’ll have our work cut out to understand what that means.”
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The team arrived over the buried river just in time to make another interesting observation. The researchers set up camp a few days beforehand record-breaking eruption the Hunga Tonga-Hunga Ha’apai volcano in Tonga on January 15. The massive explosion caused pressure waves that rang like a bell in the earth’s atmosphere, and sensors the researchers placed on the ice surface recorded similar pressure waves moving through the underground chamber. “Seeing the effect of the Tongan volcano erupting thousands of miles away was quite remarkable,” Stevens said. “It’s a reminder of how connected our whole planet is.”
Scientists will continue to study the newly discovered subsurface ecosystem and hope to learn more about how the nutrients in the water circulate through Antarctica’s subsurface water networks to support the abundance of life there.
But the researchers also worry that even hidden ecosystems like this one could be threatened by rapidly warming temperatures climate change. “The climate is changing, and there are some key areas that science has yet to understand,” Steven said. “But what is clear is that major changes are afoot.”
Originally published on Live Science.
https://www.livescience.com/hidden-ecosystem-under-antarctic-ice Discovery of ‘hidden world’ under Antarctic ice has scientists ‘jumping for joy’