Deep beneath the Antarctic ice sheet, floods of water from buried lakes can hurry glaciers along on their slow slide towards the sea, according to a new study that tracked recent floods beneath the Byrd Glacier. “It’s like putting in a squirt of oil,” says Andy Smith of the British Antarctic Survey, who was not involved in this latest study. “The water lubricates the base of the glacier” [New Scientist]. The findings will help researchers understand the movement of glaciers around the world, a matter of great interest to climate scientists who are investigating how rapidly ice sheets may melt into the ocean due to global warming.
Researchers discovered only recently that inaccessible subglacial lakes in Antarctica periodically shed huge quantities of water. Data collected by a satellite launched in 2003 … revealed a complex network of subglacial plumbing in which water periodically cascades from one hidden reservoir to another [AFP]. The water in the lakes remains liquid, despite being buried beneath a mile of ice in some places, due to warmth from the underlying rock. Now, researchers have shown that these hidden floods affect the thick mountains of ice above.
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A new analysis of Antarctic weather conditions has found that human-caused global warming is to blame for the changing climate at the south pole, according to a new study. In its landmark Fourth Assessment Report, the Intergovernmental Panel on Climate Change (IPCC) declared in 2007 that human influence on climate “has been detected in every continent except Antarctica” [Nature News]. Now, researchers have evidence that even that final frontier is feeling the heat from human activities.
In the study, published in Nature Geoscience [subscription required], researchers compared 100 years of Antarctic and Arctic climate records to the results of two sets of computerized climate models. Both sets factored in the effects of natural phenomena, such [as] volcanic eruptions and solar sunspot cycles, but only one set factored in the consequences of human activities that can affect climate, such as rising levels of the greenhouse gas carbon dioxide and fluctuations in the amount of ozone in the stratosphere. It was the models which included human factors that most closely matched the temperature profiles recorded at the poles. “For me, it can’t be more clear that human activity is responsible” [New Scientist], said study coauthor Alexey Karpechko.
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An international team of bundled-up scientists will soon set off for Antarctica’s interior in a quest to learn about the continent’s most massive and mysterious mountain range; although the Gamburtsev mountains are as high and mighty as Europe’s Alps, even the tallest peak is buried beneath 2 miles of ice. Now, during the southern hemisphere’s summer, the researchers will investigate how the Gamburtsevs formed in a place where scientists say no mountains should be.
American researcher Robin Bell, who will be making the trek, explains that there are two “easy” ways to form mountains, and neither makes sense in Antarctica: “One is colliding continents, but after they collide they tend to erode; and the last collision was 500-million-plus years ago…. The other way is a hotspot, [with volcanoes punching through the crust] like in Hawaii; but there’s no good evidence for underneath the ice sheet being that hot. I like to say it’s rather like being an archaeologist and opening up a tomb in a pyramid and finding an astronaut sitting inside. It shouldn’t be there” [BBC News].
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About 240 million years ago, a 15-foot amphibian with a nasty bite ruled the Antarctic plains, say paleontologists who have described the creature for the first time. Fossils show that the predator, newly named Kryostega collinsoni, had an extra set of teeth protruding from the roof of its mouth, which helped it shred flesh and hold struggling prey still in its mouth.
The animal, which researchers called Antarctica’s top predator in the Triassic Period, resembled a modern crocodile but was actually a temnospondyl, a prehistoric amphibian that was an early relative of salamanders and frogs. Because of their odd mixture of characteristics, members of this group are sometimes nicknamed “crocamanders” or “frogodiles” [Discovery News]. The new species will be described in the forthcoming issue of the Journal of Vertebrate Paleontology.
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In a cold, desert region of Antarctica, paleontologists have discovered the tiny fossils of shrimp-like creatures that lived in lakes during a more temperate era. The finding help refine the timing of the climate shift that gave rise to Antarctica’s remarkable Dry Valleys, a landscape akin to Mars [BBC News].
The well-preserved fossils of ostracods, a type of small crustaceans, came from… Antarctica’s Transantarctic Mountains and date from about 14 million years ago. The fossils were a rare find, showing all of the ostracods’ soft anatomy in 3-D [LiveScience]. The ostracods couldn’t survive in the Dry Valleys under current conditions, which include mean annual temperatures of minus 13 degrees Fahrenheit, indicating that the continent was a very different place 14 million years ago.
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