Antarctica // Current

Antarctic Icebergs Drift Toward New Zealand

In yet another case of nature defying skeptics, these pesky icebergs don't seem to... more

Progresshiv
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Drillers Seek Scotch Lost in Antarctica in 1909

A beverage company has asked a team to drill through Antarctica's ice for a lost cache... more

jmsrmy
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Famous Explorer, Mike Horn, has a history of World Record Expeditions

Reading through the famous explorer Mike Horn's book Conquering the Impossible about... more

Luke_Bream
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Frigid Antarctica loaded with viruses

Antarctica's icy lakes are home to a surprisingly diverse community of viruses, including some that were previously unidentified, a new study finds.

At first glance, Antarctica's freshwater lakes don't seem very hospitable to life. They remain frozen for a good nine months out of the year, and they contain very few nutrients. Some of these lakes have little animal life and are dominated by microorganisms, including algae, bacteria, protozoans and viruses.

With few animal and microbial predators around, viruses likely play an important role in controlling the abundance of other microorganisms, the researcher say. However, these viruses have been historically hard to study since many cannot be grown in a laboratory. But thanks to new genome sequencing technology, scientists can identify viruses without needing to grow them.

"We are just starting to uncover the world of viruses, and this is changing the way we think about viruses and the role they play in microbial ecosystems," said Antonio Alcami, a researcher from the Spanish Research Council.

A virus is little more than a package of DNA surrounded by a capsule structure. To survive, viruses must hijack, or infect, living cells and use the host's equipment to replicate.

Alcami and his colleagues analyzed DNA from viruses found in water samples collected from Antarctica's Lake Limnopolar, a surface lake on Livingston Island. They found nearly 10,000 species, including some small DNA viruses that had never before been identified. In total, the viruses were from 12 different families, some of which may be completely new to science, the researchers suggest.

The results reveal this Antarctic lake supports a virus community that's more diverse than most aquatic environments studied in the world so far — a surprising find considering that the polar region is generally thought to have low biological diversity due to the extreme environmental conditions. The scientists speculate the newly discovered viruses may have adapted specifically to thrive in such harsh conditions.

The team also found the community of viruses changed dramatically depending on the season. When the lake was ice-covered in the spring, the liquid water under the ice was inhabited by mostly small viruses, but in the summer months when the ice melted, the lake was home to mostly larger viruses.

"It looks like a completely different lake in summer," Alcami said. The scientists think the shift might be due to an increase in algae in the summertime, which the larger viruses infect.
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Good reason to not dig too deep.Antarctica's icy lakes are home to a surprisingly diverse community of viruses,... more

JanforGore
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SHOCKING NEW GLOBAL-WARMING DATA / TIPPING-POINT REACHED ! = PERMAFROST MELTING IN ARCTIC !

SHOCKING NEW NASA DATA / NEW PREDICTION = "3 TO 5 YEARS NO ICE IN ARCTIC" THE... more

gerardange
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19 days ago
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THE TRUTH ABOUT GLOBAL WARMING... THE REALLY~ INCONVENIENT TRUTH

Global warming... is much worse that you think. PLEASE SELECT: "WATCH FULL... more

gerardange
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15 Million Years Ago Antarctica was 112 Degrees F in the Shade!

An international team of scientists now have proof of a sudden, remarkably warm period in Antarctica that occurred about 15.7 million years ago and lasted for a few thousand years.

Last year, as Sophie Warny, LSU assistant professor of geology and geophysics was studying samples sent to her from the latest Antarctic Geologic Drilling Program, or ANDRILL one sample stood out as a complete anomaly.

“First I thought it was a mistake, that it was a sample from another location, not Antarctica, because of the unusual abundance in microscopic fossil cysts of marine algae called dinoflagellates. But it turned out not to be a mistake, it was just an amazingly rich layer,” said Warny. “I immediately contacted my U.S. colleague, Rosemary Askin, our New Zealand colleagues, Michael Hannah and Ian Raine, and our German colleague, Barbara Mohr, to let them know about this unique sample as each of our countries had received a third of the ANDRILL samples.”

The two scientists in charge of the drilling, David Harwood of University of Nebraska – Lincoln, and Fabio Florindo of Italy, were equally excited about the discovery,” said Warny. “They had noticed that this thin layer had a unique consistency that had been characterized by their team as a diatomite, which is a layer extremely rich in fossils of another algae called diatoms.”

All research parties involved met at the Antarctic Research Facility at Florida State University in Tallahassee. Together, they sampled the zone of interest in great detail and processed the new samples in various labs. One month later, the unusual abundance in microfossils was confirmed.

Among the 1,107 meters of sediments recovered and analyzed for microfossil content, a two-meter thick layer in the core displayed extremely rich fossil content. This is unusual because the Antarctic ice sheet was formed about 35 million years ago, and the frigid temperatures there impede the presence of woody plants and blooms of dinoflagellate algae.

“We all analyzed the new samples and saw a 2,000 fold increase in two species of fossil dinoflagellate cysts, a five-fold increase in freshwater algae and up to an 80-fold increase in terrestrial pollen,” said Warny. “Together, these shifts in the microfossil assemblages represent a relatively short period of time during which Antarctica became abruptly much warmer.”

These palynomorphs, a term used to described dust-size organic material such as pollen, spores and cysts of dinoflagellates and other algae, provide hard evidence that Antarctica underwent a brief but rapid period of warming about 15 million years before present.

These startling results will offer new insight into Antarctica’s climatic past – insights that could potentially help climate scientists better understand the current climate change scenario.

“In the case of these results, the microfossils provide us with quantitative data of what the environment was actually like in Antarctica at the time, showing how this continent reacted when climatic conditions were warmer than they are today,” said Warny.

According to the researchers, these fossils show that land temperatures reached a January average of 10 degrees Celsius – the equivalent of approximately 50 degrees Fahrenheit – and that estimated sea surface temperatures ranged between zero and 11.5 degrees Celsius. The presence of freshwater algae in the sediments suggests to researchers that an increase in meltwater and perhaps also in rainfall produced ponds and lakes adjacent to the Ross Sea during this warm period, which would obviously have resulted in some reduction in sea ice.

These findings most likely reflect a poleward shift of the jet stream in the Southern Hemisphere, which would have pushed warmer water toward the pole and allowed a few dinoflagellate species to flourish under such ice-free conditions. Researchers believe that shrub-like woody plants might also have been able to proliferate during an abrupt and brief warmer time interval.An international team of scientists now have proof of a sudden, remarkably warm period... more