Showing posts with label Antarctica. Show all posts
Showing posts with label Antarctica. Show all posts

Thursday, February 16, 2012

Fish of Antarctica Threatened by Climate Change

ScienceDaily (Feb. 13, 2012) — A Yale-led study of the evolutionary history of Antarctic fish and their "anti-freeze" proteins illustrates how tens of millions of years ago a lineage of fish adapted to newly formed polar conditions -- and how today they are endangered by a rapid rise in ocean temperatures.



"A rise of 2 degrees centigrade of water temperature will likely have a devastating impact on this Antarctic fish lineage, which is so well adapted to water at freezing temperatures," said Thomas Near, associate professor of ecology and evolutionary biology and lead author of the study published online the week of Feb. 13 in the Proceedings of the National Academy of Sciences.
The successful origin and diversification into 100 species of fish, collectively called notothenioids, is a textbook case of how evolution operates. A period of rapid cooling led to mass extinction of fish acclimated to a warmer Southern Ocean. The acquisition of so-called antifreeze glycoproteins enabled notothenioids to survive in seas with frigid temperatures. As they adapted to vacant ecological niches, new species of notothenioids arose and contributed to the rich biodiversity of marine life found today in the waters of Antarctica.

Tuesday, December 20, 2011

Titanosaur bone found in Antarctica

Long before the arrival of penguins, giant plant-eating dinosaurs roamed Antarctica.


Scientists discovered a fossil tail bone belonging to a titanosaur, a family that included the largest land animals ever to walk the Earth.

Titanosaurs were sauropods, four-legged herbivorous dinosaurs with long necks and tails.

Sauropods included some 150 species whose remains have been found around the world, but never in Antarctica until now.

The new specimen was discovered on James Ross Island by an Argentinian-led team and it consists of section of vertebrae almost 20cm long believed to have come from the middle third of the dinosaur's tail.

Scientists identified it as belonging to a "lithostrotian titanosaur" from the Late Cretaceous period around 70 million years ago.

The discovery is reported in the German journal Naturwissenschaften - The Science of Nature.

Authors Dr Ignacio Alejandro Cerda, from the Conicet research institute in Argentina, and colleagues wrote: "Our finding indicates that advanced titanosaurs achieved a global distribution at least by the Late Cretaceous."

Titanosaurs included the mighty Argentinosaurus, which may have reached 100ft in length.

However, the discovery of a single vertebrae fossil yielded too little information to allow speculation about the dinosaur's species.


http://www.google.com/hostednews/ukpress/article/ALeqM5gB64R8mYY7MnGUKAk15IZ7ZMdLDQ?docId=N0540141324303131758A

Wednesday, November 16, 2011

Migrating whale numbers hit 50-year high

There has been a rise in the number of migrating whales. They travel on a 5,000km (3,100 miles) round trip to give birth off the coast of Australia before heading back to Antarctica to their main feeding grounds.

It is the highest number seen in half a century.

Duncan Kennedy reports from Sydney.

Watch video here ...

Tuesday, November 15, 2011

British engineering team heads to Antarctica to explore hidden lake

At the frontier of exploration
October 2011: A British engineering team is heading off to Antarctica for the first stage of an ambitious scientific mission to collect water and sediment samples from a lake buried beneath 3km of solid ice.

This extraordinary research project, at the frontier of exploration, will yield new knowledge about the evolution of life on Earth and other planets, and will provide vital clues about the Earth's past climate.

One of the most remote and hostile environments on EarthTransporting nearly 70 tonnes of equipment the ‘advance party' will make a journey almost 16,000km from the UK to subglacial Lake Ellsworth on the West Antarctic Ice Sheet (WAIS). It is one of the most remote and hostile environments on Earth with -25°C temperatures.

Their task is to prepare the way for the ‘deep-field' research mission that will take place one year later. In October next year, a team of ten scientists and engineers will use state-of-the-art hot-water drilling technology to make a 3km bore hole through the ice. They will then lower a titanium probe to measure and sample the water followed by a corer to extract sediment from the lake.

Lake Ellsworth is likely to be the first of Antarctica's 387 known subglacial lakes to be measured and sampled directly through the design and manufacture of space-industry standard ‘clean technology'.

'Only now do we have the expertise to explore this hidden world'For years scientists have speculated that new and unique forms of microbial life could have evolved in this cold, pitch black and isolated environment. Sediments on the lake bed are likely to reveal vital clues about the history of life in the lake and the ancient history of the WAIS, including past collapse.

The Lake Ellsworth Programme principal investigator, Professor Martin Siegert from the University of Edinburgh, says: ‘For almost 15 years we've been planning to explore this hidden world. It's only now that we have the expertise and technology to drill through Antarctica's thickest ice and collect samples without contaminating this untouched and pristine environment.

‘We are tremendously excited - this is a frontier science project with engineering and technology at the forefront. Scientists and engineers from two of the Natural Environment Research Council's (NERC) centres of excellence, working in partnership with scientists from eight UK universities, make up the consortium that will search for life in this extreme environment and discover the secrets locked in the sediments.

‘Every piece of equipment is a bespoke design and they have been built in partnership with several UK businesses.'

'This could define limits at which life can no longer exist'Dr David Pearce, science coordinator at British Antarctic Survey, is part of the team leading the ‘search for life' in the lake water. He says: ‘Finding life in a lake that could have been isolated from the rest of the biosphere for up to half a million years will tell us so much about the potential origin of and constraints for life on Earth, and may provide clues to the evolution of life on other extraterrestrial environments.

‘If we find nothing this will be even more significant because it will define limits at which life can no longer exist on the planet.'

The unique 5m long water sampling probe was designed and built by engineers at the National Oceanography Centre in Southampton. Made of the highest grade of titanium to ensure maximum sterility and strength, it will collect 24 water samples at different lake depths.

Scientists at British Antarctic Survey and Durham University, working in partnership with Austrian business UWITEC, have designed and built a sediment corer, which can extract a core up to three metres long. The unique percussion-driven piston corer is strong enough to penetrate even the most compacted glacial sediments to extract a core sample.

http://www.wildlifeextra.com/go/news/antarctica-exploration2011.html#cr

Friday, November 4, 2011

Major berg forming in Antarctica (via Dawn Holloway)




Read on ...

Monday, October 17, 2011

'Criminal' penguin caught on film

A "criminal" stone-stealing Adelie penguin has been captured on camera by a BBC film crew.

The team, filming for the documentary Frozen Planet, spent four months with the penguin colony on Ross Island, Antarctica.

The footage they captured shows a male penguin stealing stones from its neighbour's nest.

The birds build their stone nests to elevate and protect their eggs from run-off when the Antarctic ice melts.

Males with the best nests are more likely to attract a mate, so, in a colony of half a million penguins, the best stones are highly prized.

Read on...