Subscribe free to our newsletters via your
. Earth Science News .




ICE WORLD
New insight into accelerating summer ice melt on the Antarctic Peninsula
by Staff Writers
London, UK (SPX) Apr 16, 2013


Ice core camp.

A new 1000-year Antarctic Peninsula climate reconstruction shows that summer ice melting has intensified almost ten-fold, and mostly since the mid 20th Century. Summer ice melt affects the stability of Antarctic ice shelves and glaciers.

The research, published this week in the journal Nature Geoscience, adds new knowledge to the international effort that is required to understand the causes of environmental change in Antarctica and to make more accurate projections about the direct and indirect contribution of Antarctica's ice shelves and glaciers to global sea level rise.

In 2008 a UK-French science team drilled a 364-metre long ice core from James Ross Island, near the northern tip of the Antarctic Peninsula, to measure past temperatures in the area. They discovered that this ice core could also give a unique and unexpected insight into ice melt in the region.

Visible layers in the ice core indicated periods when summer snow on the ice cap thawed and then refroze. By measuring the thickness of these melt layers the scientists were able to examine how the history of melting compared with changes in temperature at the ice core site over the last 1000-years.

Lead author Dr Nerilie Abram of The Australian National University and British Antarctic Survey (BAS) says,

"We found that the coolest conditions on the Antarctic Peninsula and the lowest amount of summer melt occurred around 600 years ago. At that time temperatures were around 1.6C lower than those recorded in the late 20th Century and the amount of annual snowfall that melted and refroze was about 0.5%. Today, we see almost ten times as much (5%) of the annual snowfall melting each year.

"Summer melting at the ice core site today is now at a level that is higher than at any other time over the last 1000 years. And whilst temperatures at this site increased gradually in phases over many hundreds of years, most of the intensification of melting has happened since the mid-20th century."

This is the first time it has been demonstrated that levels of ice melt on the Antarctic Peninsula have been particularly sensitive to increasing temperature during the 20th Century.

Dr Abram explains, "What that means is that the Antarctic Peninsula has warmed to a level where even small increases in temperature can now lead to a big increase in summer ice melt."

Dr Robert Mulvaney from the British Antarctic Survey led the ice core drilling expedition and co-authored the paper. He says,

"Having a record of previous melt intensity for the Peninsula is particularly important because of the glacier retreat and ice shelf loss we are now seeing in the area. Summer ice melt is a key process that is thought to have weakened ice shelves along the Antarctic Peninsula leading to a succession of dramatic collapses, as well as speeding up glacier ice loss across the region over the last 50 years."

In other parts of Antarctica, such as the West Antarctic Ice Sheet, the picture is more complex and it is not yet clear that the levels of recent ice melt and glacier loss are exceptional or caused by human-driven climate changes.

Dr Abram concludes, "This new ice core record shows that even small changes in temperature can result in large increases in the amount of melting in places where summer temperatures are near to 0C, such as along the Antarctic Peninsula, and this has important implications for ice instability and sea level rise in a warming climate."

This research was funded by the Natural Environment Research Council. Dr Abram is an Australian Research Council Queen Elizabeth II Fellow. Issued by the British Antarctic Survey and the Australian National University Press Offices.

.


Related Links
British Antarctic Survey
Beyond the Ice Age






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








ICE WORLD
Recent climate, glacier changes in Antarctica at the 'upper bound' of normal
Seattle WA (SPX) Apr 16, 2013
In the last few decades, glaciers at the edge of the icy continent of Antarctica have been thinning, and research has shown the rate of thinning has accelerated and contributed significantly to sea level rise. New ice core research suggests that, while the changes are dramatic, they cannot be attributed with confidence to human-caused global warming, said Eric Steig, a University of Washin ... read more


ICE WORLD
Fukushima leaking radioactive water

IAEA begins fresh probe into Japan's Fukushima

Fukushima plant springs another radioactive leak

Hong Kong ferry crash captains face manslaughter charges

ICE WORLD
High pressure gold nanocrystal structure revealed

Scientists design new adaptive material inspired by tears

UC Research Demonstrates Why Going Green Is Good Chemistry

Florida Tech professors present 'dark side of dark lightning' at conference

ICE WORLD
Mass sea lion strandings baffle California

Cutting specific pollutants would slow sea level rise

Scientists stress need for national marine biodiversity observation network

Sea Mammals Find U.S. Safe Harbor

ICE WORLD
New insight into accelerating summer ice melt on the Antarctic Peninsula

Recent climate, glacier changes in Antarctica at the 'upper bound' of normal

Austria's glaciers shrank in 2012: study

New chart shows the entire topography of the Antarctic seafloor in detail

ICE WORLD
Taiwan to ban killing of live poultry in markets

Chinese thirst for baby formula boosts Danone sales

Salt-tolerant rice bred at Philippines institute

China media urge eating poultry despite bird flu

ICE WORLD
Huge quake hits Iran, kills 34 in Pakistan

'Sandy' removed from hurricane name list

Indonesian floods kill eleven

Strong 6.3-magnitude quake hits western Japan

ICE WORLD
Chad quits Mali war, French stick it out

China invested $1.5bn in Algeria in a decade: envoy

Alleged drug lord seized, but Africa trade grows

Sudan defence minister sees 'end' to Darfur uprising

ICE WORLD
New Research Reveals How Human Ancestor Walked, Chewed, and Moved

Pottery reveals Ice Age hunter-gatherers' taste for fish

Google adds 'digital estate planning' to its services

Better Understanding of Human Brain Supports National Security




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement