Study tracks blue whales across Southern Ocean

New data will help shape conservation efforts in the waters around Antarctica

Naval training exercises off the coast of California could pose a threat to endangered marine mammals.

Australian and New Zealand researchers have tracked blue whales across thousands of miles in the Southern Ocean to help inform conservation efforts. Photo courtesy NOAA.

Staff Report

FRISCO — As a keystone species in marine ecosystems, blue whales have a significant impact in the ocean around Antarctica, but the population dynamics of the species in the region are still a mystery as the marine mammals recover from the decimation of the whaling era.

That may change following the recent six-week Australia-New Zealand Antarctic Ecosystem Voyage voyage, as researchers tracked the world’s largest creatures across thousands of miles of ocean, detecting their songs from as far as 750 kilometers away. Continue reading

How do Antarctica snowfall rates affect sea level rise?

New ice core analysis shows less of an ‘offset’ than most models currently project

Antarctica permafrost

Increasing snowfall in Antarctica will moderate the rate of global sea level rise — but not as much as previously thought. bberwyn photo.

Staff Report

FRISCO — Detailed ice core records from Antarctica show that snowfall over the frozen continent increased about 5 percent for each degree (Celsius) of warming as Earth emerged from the last ice age.

The findings confirm that the increased snowfall will slightly offset sea level rise, as suggested by other research — but not as much as previously thought. That means that some computer models may be underestimating the amount and rate of future sea level rise if they’re based on inaccurate assumptions. Continue reading

Climate: Too cold for penguins?

Emperor penguin colony near Halley Bay. IMAGE COURTESY DIGITALGLOBE.

Emperor penguin colony near Halley Bay. IMAGE COURTESY DIGITALGLOBE.

Genetic study tracks history of Antarctica’s emperor penguin populations

Staff Report

FRISCO — A genetic study shows that emperor penguins may have just barely survived the last ice age, with a few scattered populations  enduring centuries of bitter cold and ice.

The study covers about 30,000 years and suggests that only three populations survived, including a climate refuge of sorts in the Ross Sea, where emperors may have been able to breed around a relatively small area of open water. The emperor penguins in that region evolved to become genetically distinct from other populations, which may support arguments for creating a Ross Sea marine protected area. Continue reading

Climate: New ice core data help show long-term rainfall record for parts of Australia

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A recent weather satellite image of Australia, via NASA.

‘The Millennium Drought was far from an exceptional event for eastern Australia during the past thousand years …’

FRISCO — Even without the added factor of global warming, eastern Australia is susceptible to climate extremes, including long-lasting droughts that could put a huge strain on water storage and delivery systems.

Researchers say a 1,000-year ice core record from Antarctica shows the recent “Millennium Drought” actually wasn’t all that unusual in the context of Australia’s long-term climate history. Continue reading

Sonar study finds blue whale ‘hotspots’ in Southern Ocean

Whale populations around Antarctica still rebounding from industrial whaling era

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New sonar techniques could help pinpoint blue whale numbers in the Southern Ocean and identify important habitat. Photo courtesy NOAA.

Staff Report

FRISCO — After a century of relentless industrial whaling, blue whales were nearly extirpated from the Southern Ocean around Antarctica, The giant marine mammal is now making a comeback, and resurgent whale numbers could affect other parts of the ecosystem.

Other recent research has shown blue whale numbers rebounding off the coast of California, and biologists with the British Antarctic Survey recently reported that satellite technology could also help count whales.

But for the Southern Ocean, scientists don’t have a good grasp of population numbers. Between 1978 and 2010 blue whale surveys recorded only 216 visual encounters, so new research by Australian scientists may help identify important habitat areas and pinpoint numbers, which helps inform conservation strategies, with several large marine protected areas in the works for Antarctica. Continue reading

East Antarctica ice sheets not immune to global warming

An international research team explores the geological history of the Gamburtsev Mountains, buried under two miles of ice in eastern Antarctica.

New research shows that even the frigid fringes of East Antarctica are melting away under warming seas.

Warming ocean melts ice from below

Staff Report

FRISCO — It’s not just the West Antarctic ice sheets that are melting away as the surrounding ocean warms, Australian scientists reported after a six week voyage to the eastern side of the frozen continent.

A series of detailed measurements show that warm ocean water is melting the Totten Glacier — the largest in the region, with enough ice to raise sea level by several meters, according to the findings by the Australian Antarctic Division and partnering research organizations. Continue reading

Scientists probe Antarctic ice sheet for climate clues

New data to help inform projections of sea-level rise

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Researchers are exploring Antarctic ice sheets. bberwyn photo.

Staff Report

FRISCO — Drilling deep into Antarctic ice this month, researchers were able for the first time to take a close look at the grounding zone of an ice sheet, where Antarctic ice, land and sea all converge.

Sediment samples from the half-mile bore hole will provide clues about the mechanics of ice sheets and their potential effects on sea-level rise, but the drilling also revealed an unsuspected population of fish and invertebrates living beneath the ice sheet, the farthest south that fish have ever been found. Continue reading

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