Posted on September 19, 2013 by Bob Berwyn
Strong storms help push water through the Drake Passage, and beneath the surface, the surging currents help mix the ocean from top to bottom. bberwyn photo.
Underwater mountains help churn up the ocean, fueling the carbon cycle
By Summit Voice
FRISCO — The Drake Passage, between the tip of South America and the Antarctic Peninsula, is well known for wild storms and big swell, but it turns out that turbulence isn’t just at the surface.
Far beneath the breaking whitecaps, the area is a crucial ocean mixing ground, where surface water is exchanged with deep water as currents rush over undersea mountains. Those mixing of water layers are crucial to regulating the Earth’s climate and ocean currents, according to researchers who recently traced how that mixing happens. (more…)
Filed under: Antarctica, climate and weather, Environment | Tagged: Antarctic Peninsula, British Antarctic Survey, Drake Passage, ocean mixing carbon cycle, oceans, Southern Ocean, University of Exeter, Woods Hole Oceanographic Institution | Leave a Comment »
Posted on September 11, 2013 by Bob Berwyn
Core samples from subglacial lake sediments show surprising biological diversity
Retreating ice on the Antarctic Peninsula has given scientists an opportunity to search for life in subglacial environments. bberwyn photo
By Summit Voice
FRISCO — Burrowing 10 feet down into the primal muck at the edge of a receding ice sheet in Antarctica, scientists with the British Antarctic Survey found what they had long been looking for — traces of microbial life dating back nearly a hundred thousand years, including strands of DNA associated with previously unknown bacteria.
For decades, researchers speculated that so-called extremophiles might exist in the cold and dark lakes hidden deep beneath the Antarctic ice sheet. Organisms living in subglacial lakes could hold clues for how life might survive on other planets.
“This is the first time microbes have been identified living in the sediments of a subglacial Antarctic lake and indicates that life can exist and potentially thrive in environments we would consider too extreme,” said lead author David Pearce, who was with the British Antarctic Survey and is now at the University of Northumbria. (more…)
Filed under: Antarctica, biodiversity, climate and weather, Environment, global warming | Tagged: British Antarctic Survey, extremophiles, Lake Ellsworth, Lake Hodgson | 1 Comment »
Posted on September 9, 2013 by Bob Berwyn
Robots, seal-mounted instruments and remote-operated subs part of ambitious project to study Pine Island, Thaite glaciers
West Antarctic ice sheets are melting fast, and scientists want to know why. bberwyn photo
By Summit Voice
FRISCO — With this year’s Antarctic research season starting to ramp up, a key focus is taking a closer look at ice sheets on the western side of the continent, where rapid ice loss from the Pine Island and Thwaite glaciers could affect sea level worldwide.
A team of researchers led by the British Antarctic Survey aims to discover what’s causing the recent rapid ice loss, and whether this loss will continue to increase or slow down. (more…)
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: Amundsen Sea, Antarctica, British Antarctic Survey, Pine Island Glacier, sea level, West Antarctic Ice Sheet | Leave a Comment »
Posted on August 30, 2013 by Bob Berwyn
‘Unprecendented rate of ecological change’
By Summit Voice
FRISCO — Finding ways to assess the impacts of global warming in Antarctica isn’t always easy. Measurements of ice help show some of the changes but don’t tell the whole story, so British researchers took a close look at a 150-year-old moss bank on the Antarctic Peninsula, one of the fastest-warming regions on Earth.
The analysis shows an unprecedented rate of ecological change since the 1960s driven by warming temperatures, according to the findings published Aug. 29 in Current Biology. Temperatures on the Antarctic Peninsula have increased by up to 0.56 degrees Celsuis per decade since the 1950s. (more…)
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: Antarctic Peninsula, British Antarctic Survey, climate change, Environment, global warming, University of Cambridge, University of Exeter | Leave a Comment »
Posted on August 21, 2013 by Bob Berwyn
Warmer ocean temps could affect productivity
By Summit Voice
FRISCO — A new study suggests that global warming could cut krill habitat by 20 percent — and more in some critical areas where land-based animals like penguins and seals depend on the tiny crustaceans for food.
The research, conducted by a team of scientists with the British Antarctic Survey and the Plymouth Marine Laboratory, focused on the effects of warming sea surface temperatures. (more…)
Filed under: Antarctica, biodiversity, climate and weather, Environment, global warming | Tagged: Antarctic krill, biodiversity, British Antarctic Survey, climate change, Environment, global warming, krill, Plymouth Marine Laboratory, Southern Ocean, Weddell Sea | Leave a Comment »
Posted on July 16, 2013 by Bob Berwyn
Iceberg calving to be less of a factor as glaciers retreat
By Summit Voice
FRISCO — Greenland’s melting ice cap will continue to contribute to sea level rise, but iceberg calving will become less of a factor as glaciers retreat inland. Instead, surface melting and runoff will account for more than 80 percent of ice cap’s contribution to sea level rise, according to new research from the Vrije Universiteit Brussel.
Changes in its total mass are governed by two main processes — fluctuations in melting and snowfall on its surface, and changes to the number of icebergs released from a large number of outlet glaciers into the ocean. The ice loss from the ice sheet has been increasing during the last decade, with half of it attributed to changes in surface conditions with the remainder due to increased iceberg calving. (more…)
Filed under: Arctic, climate and weather, Environment, global warming | Tagged: British Antarctic Survey, climate, Environment, global warming, greenland, Greenland ice sheet, ice2sea, sea level rise, Vrije Universiteit Brussel | 1 Comment »
Posted on July 3, 2013 by Bob Berwyn
King crabs are probably long-time residents of Antarctic waters, according to new research led by the British Antarctic Survey. Photo courtesy NOAA.
New study of fossil record suggests the spiny crustaceans are not recent invaders
By Summit Voice
FRISCO — A comprehensive look at the fossil record of king crabs in Antarctica suggests the long-legged crustaceans have probably been there all along — and didn’t arrive as invaders due to global warming.
The new study challenges findings from a couple of years ago that warming seas may have enabled the crabs to start gaining a foothold in the region, potentially at the expense of native species.
The invader theory surfaced two years ago following the discovery of a major colony of king crabs (Lithodidae) in the Palmer Deep, a basin in the continental shelf off the Antarctic Peninsula. It was thought the species may have left the continent between 40 and 15 million years ago and was returning as seawater temperatures rose.
The new findings have been published in the online journal PLOS ONE. The scientists, led by British Antarctic Survey marine biologist Huw Griffiths, claim the “invasion” hypothesis is fundamentally flawed because it relied upon poor fossil records relating to a completely different group of crabs and that sampling of the extant species is far too limited to draw any firm conclusions. (more…)
Filed under: Antarctica, biodiversity, climate and weather, Environment, global warming | Tagged: Antarctica, biodiversity, British Antarctic Survey, invasive species, King crabs, South Orkney Islands, Southern Ocean | Leave a Comment »
Posted on May 16, 2013 by Bob Berwyn
The EU’s ice2sea program helps to determine potential future impacts of rising sea levels.
Research focuses on contribution of melting glaciers, ice caps and ice shelves
By Summit Voice
FRISCO — After four years of studies and more than 150 peer-reviewed papers, The EU-funded ice2sea program has concluded that melting ice may not contribute as much to sea level rise as some other studies have suggested.
Under a moderate greenhouse gas emissions scenario, the contribution from continental ice will likely amount to between 3.5 and 36.8 centimeters (1.4 to 14.5 inches) by 2100, the program’s leaders said this week, unveiling a new report that summarizes their research. The report is online at the ice2sea home page.
Some of the ice2sea studies have:
The new report includes several case studies outlining the impacts of sea level rise to specific areas, including economically valuable developed areas like the port of Rotterdam and the Thames Estuary, as well as natural areas with unique natural values, like the Machair ecosystems in Ireland and Scotland that thrive in a delicate balance of land and sea. (more…)
Filed under: Antarctica, Arctic, climate and weather, Environment, global warming | Tagged: British Antarctic Survey, climate, Current sea level rise, global warming, ice2sea program, Intergovernmental Panel on Climate Change, sea level rise | Leave a Comment »
Posted on May 8, 2013 by Bob Berwyn
Study shows topography is a key factor in controlling ice flow
A new study helps pinpoint how many icebergs may from as Greenland’s glaciers are subjected to global warming. Photo courtesy British Antarctic Survey.
By Bob Berwyn
FRISCO — Greenland’s swift outflow glaciers are sensitive to warming air and ocean temperatures, but a new study published in the journal Nature indicates that the recent acceleration of glacial flow isn’t continuing at a linear rate.
The shape of the ground and seafloor beneath the glaciers is crucial in determining how they respond to climate change — how fast they move and how much they will contribute to sea level rise in coming decades.
“What we are saying is that we shouldn’t extrapolate the rate of the last 10 years into the future … If you study these glaciers separately, they show different behavior,” said lead author Dr. Faezeh Nick, of the Université Libre de Bruxelles, describing the work done on the Petermann, Kangerdlugssuaq, Helheim and Jakobshavn Isbræ glaciers. Together, they drain about 22 percent of the Greenland ice sheet. (more…)
Filed under: climate and weather, Environment, global warming | Tagged: British Antarctic Survey, climate change, Current sea level rise, greenland, Petermann Glacier, Université Libre de Bruxelles | 1 Comment »
Posted on April 19, 2013 by Bob Berwyn
Study shows climate change may affect overall population numbers
Changes in Antarctic clam populations could have a ripple effect on other species in the region like these blue-eyed cormorants in the South Shetlands. Bob Berwyn photo.
By Summit Voice
FRISCO — Warming ocean temperatures and increased glacial outflow around Antarctica may have a big impact on clams living on the ocean floor. Younger clams try to move away when they sense warmer temperature or reduced oxygen levels, but older clams stay put.
The findings by a team of British and German scientists indicate how climate change may affect biodiversity in the region, suggesting that the overall population of Antarctic clams may dwindle, since it’s the older animals that reproduce.
“Our study shows that the physiological flexibility of young clams diminishes as they get older. However, the species has evolved in such a way that the fittest animals, that can tolerate life in an extreme environment, survive to reproduce into old age,” said Doris Abele, of the Alfred Wegener Institute in Germany. “Climatic change, affecting primarily the older clams, may interfere with this evolutionary strategy, with unpredictable consequences for ecosystems all around Antarctica.” (more…)
Filed under: Antarctica, biodiversity, climate and weather, Environment, global warming | Tagged: Alfred Wegener Institute for Polar and Marine Research, Antarctic clams, Antarctic Peninsula, Antarctica, biodiversity, British Antarctic Survey, climate change, global warming | Leave a Comment »