West Antarctic Ice Sheet's Collapse Triggers Sea Level Warning

w1z4rd

w1z4rd

Karmic Sangoma
Joined
Jan 17, 2005
Messages
52,146
Reaction score
8,340
Location
127.0.0.1
Two teams of scientists say the long-feared collapse of the West Antarctic Ice Sheet has begun, kicking off what they say will be a centuries-long, "unstoppable" process that could raise sea levels by as much as 15 feet.

"There's been a lot of speculation about the stability of marine ice sheets, and many scientists suspected that this kind of behavior is under way," Ian Joughin, a glaciologist at the University of Washington in Seattle, said in a news release about one of the studies published Monday. "This study provides a more qualitative idea of the rates at which the collapse could take place."

The findings from Joughin and his colleagues, appearing in the journal Science, indicate that in some places, Antarctica's Thwaites Glacier is losing tens of feet, or several meters, of ice elevation every year.

They estimate that Thwaites Glacier would probably disappear entirely in somewhere between 200 and 1,000 years. That loss would raise global sea levels by nearly 2 feet (60 centimeters). The glacier serves as a linchpin for the rest of the West Antarctic Ice sheet, which has enough frozen mass to cause another 10 to 13 feet (3 to 4 meters) of sea level rise.

A second study, published in Geophysical Research Letters, reports the widespread retreat of Thwaites and other glaciers on the West Antarctic Ice Sheet — and says the retreat can't help but continue.

"It has passed the point of no return," the research team's leader, Eric Rignot of the University of California at Irvine, told reporters during a NASA teleconference on Monday. The second study projected that the glacial retreat in Antarctica's Amundsen Sea Embayment, which includes Thwaites Glacier, would result in 4 feet (1.2 meters) of sea level rise — and open the way to more widespread retreats.

Rignot's team based their findings on a detailed analysis of radar data from two European Earth Remote Sensing satelllites, ERS-1 and ERS-2. Joughin's team relied on radar maps primarily derived from an aerial NASA survey called Operation IceBridge.

Scientists have been warning for decades that the West Antarctic Ice Sheet was in peril due to climate change, and recent readings have shown that the region is warming more quickly than expected. The loss of ice that is floating on the seas surrounding the continent would not contribute significantly to sea level rise. However, losing the ice that's currently grounded on the continent would.
Click to expand...

Read the rest (there is a lot more): http://www.nbcnews.com/science/envi...s-collapse-triggers-sea-level-warning-n103221 Including videos.
 
Earthsky article on the same issues...

The NASA/UC Irvine study points to three primary lines of evidence that cause scientists to believe the glaciers will continue to melt into the sea over time.

  • The change in flow speeds of the ice along the Western Antarctic coast. Over the past 40 years, the flow speeds of these glaciers have been increasing.
  • The slope of the terrain the glaciers are flowing over, and that terrain’s depth below sea level. All the glacier beds slope deeper below sea level as they extend farther inland. As the glaciers retreat, they cannot escape the reach of the ocean, and the warm water will keep melting them even more rapidly.
  • How much of each glacier floats on seawater. Nearly all glacier melt occurs on the underside of a glacier, on its forward section, on the part that is floating on seawater. The NASA/UC Irvine study found that glaciers in West Antarctica have stretched out and thinned over the past 40 years, so that they are now floating in places where they used to sit on land. Thus they are melting more rapidly.


Earth’s oceans are getting warmer, and warmer ocean waters are contributing to the loss of Antarctic glacial ice over time. But there is one key cause to Antarctic glacial melting, and that is shifting winds. Stronger winds are pushing warm water under coastal glaciers and melting them, scientists say. That process is expected to intensify in the coming decades.
Click to expand...
 
Still a while before Gauteng will have beachfront property ..
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X