Posted on March 19, 2015 by Bob Berwyn
Seafloor channels sluicing warm ocean water toward base of East Antarctica’s Totten Glacier
Are Antarctica’s ice sheets near a global warming tipping point? bberwyn photo.
FRISCO — Scientists say they’re a step closer to understanding the extreme thinning of East Antarctica’s largest glacier, which contains enough ice to raise global sea level by about 11 feet.
Ocean gateways are sluicing warm water toward the base of the Totten Glacier near the shoreline, undercutting the icy anchors that slow the advance of the ice toward the sea, according to researchers with the University of Texas at Austin’s Institute for Geophysics, who outline their findings in the March 16 edition of the journal Nature Geoscience.
Similar findings from the region were reported by Australian scientists just a few weeks ago, and another study showed widespread thinning of ice in East Antarctica. Continue reading
Filed under: climate and weather, Environment, global warming | Tagged: climate change, East Antarctica, Environment, global warming, sea level rise, Totten Glacier | Leave a comment »
Posted on March 17, 2015 by Bob Berwyn
New ice core analysis shows less of an ‘offset’ than most models currently project
Increasing snowfall in Antarctica will moderate the rate of global sea level rise — but not as much as previously thought. bberwyn photo.
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
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: Antarctica, climate change, global warming, sea level rise, snowfall | Leave a comment »
Posted on March 11, 2015 by Bob Berwyn
Will the West Antarctic Ice Sheet slip-slide away as the Southern Ocean warms up? bberwyn photo
A delicate balance
FRISCO — West Antarctica ice sheets are delicately anchored in place along a narrow sliver called the grounding zone, and new research shows that even slight increases in regional ocean and air temperatures are likely to destabilize the ice. The grounding zone is a sloping rock bed that lies below sea level.
In the new study, published this month in the Journal of Glaciology, Caltech scientists said future estimates of sea level rise need to take into account that the ice sheets are more sensitive to temperature perturbations driven by climate change than previously thought.
“Our results show that the stability of the whole ice sheet and our ability to predict its future melting is extremely sensitive to what happens in a very small region right at the grounding line. It is crucial to accurately represent the physics here in numerical models,” said study coauthor Andrew Thompson, an assistant professor of environmental science and engineering at Caltech. Continue reading
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: climate change, glaciology, global warming, sea level rise, West Antarctic Ice Sheet | Leave a comment »
Posted on January 22, 2015 by Bob Berwyn
A meltwater lake on the surface of the Greenland Ice Sheet. Now researchers are tracking where that water goes, and how it may affect ice sheet movement. Photo courtesy Thomas Nylen, National Science Foundation.
Surface meltwater feeds subglacial lakes
FRISCO — Scientists who recently took a close look at the “plumbing” of the Greenland Ice Sheet say that meltwater from the surface is building up lakes beneath the ice and transporting heat to the bottom of the ice sheet.
The research, led by Cornell University Earth and Atmospheric Sciences researcher Michael Willis, includes groundbreaking findings that give new information about atmospheric warming and its affect on the critical zone at the base of the ice. The warmth provided by the water could make the ice sheet move faster and alter how it responds to the changing climate. The research is detailed in a new paper published online by the journal Nature on Jan. 21. Continue reading
Filed under: Arctic, climate and weather, global warming, Greenland | Tagged: climate change, Environment, global warming, Greenland ice sheet, sea level rise | Leave a comment »
Posted on January 21, 2015 by Bob Berwyn
A green sea turtle. Photo courtesy NOAA.
‘Smart’ adaptation plans needed to protect critical beach nesting habitat
FRISCO — Florida’s strategy of trying to “harden” beaches to prevent erosion poses a serious threat to sea turtles, university scientists said this week, outlining results of a study that tracked reproduction for 30 years.
Hardening beaches puts up barriers to wildlife and impacts sea turtles’ ability to nest,” the researchers said. Continue reading
Filed under: biodiversity, climate and weather, Environment, global warming | Tagged: beach armoring, endangered species, Florida, global warming, green sea turtles, sea level rise | 1 Comment »
Posted on January 15, 2015 by Bob Berwyn
New study shows acceleration in past 20 years
Coastal flooding along the Gulf Coast. bberwyn photo.
Sea level is going up, up … up.
FRISCO — Estimating the pace of global sea level rise isn’t easy, but a team of Harvard researchers say their new study helps fill in some of the data gaps, showing that the acceleration in the rise global sea level from the 20th century to the last two decades has been significantly larger than scientists previously thought.
Part of the reason for that is because scientists may have been over-estimating sea level rise between 1900 and 1990, according to co-authors Carling Hay, a post-doctoral fellow in the Department of Earth and Planetary Sciences, and Eric Morrow, a recent PhD graduate of EPS. Continue reading
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Posted on January 13, 2015 by Bob Berwyn
Massive flows contribute to sea level rise
How fast will the Greenland Ice Sheet melt?
Credit: NASA Goddard’s Scientific Visualization Studio.
FRISCO — After criss-crossing the Greenland Ice Sheet with a helicopter and deploying a remote-operated boat, a team of UCLA-led scientists say they’ve mapped an intricate network of rivers and streams flowing on top of the ice sheet.
The water from those rivulets and rivers could be responsible for as much, if not more, sea-level rise that the ice sheet’s ephemeral lakes and the monster chunks of ice that slide into the ocean to become icebergs. Continue reading
Filed under: Arctic, climate and weather, global warming, Greenland | Tagged: climate change, global warming, Greenland ice sheet, Greenland snowmelt rivers, sea level rise, UCLA | Leave a comment »