Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



ICE WORLD
Intensifying winds could increase east Antarctica's contribution to sea level rise
by Staff Writers
Austin TX (SPX) Nov 06, 2017


A new study led by the University of Texas Institute for Geophysics has found that wind over the ocean off the coast of East Antarctica causes warm, deep waters to upwell, circulate under Totten Ice Shelf, and melt the fringes of the East Antarctic ice sheet from below.

Totten Glacier, the largest glacier in East Antarctica, is being melted from below by warm water that reaches the ice when winds over the ocean are strong - a cause for concern because the glacier holds more than 11 feet of sea level rise and acts as a plug that helps lock in the ice of the East Antarctic Ice Sheet.

Research led by The University of Texas at Austin has found that wind is responsible for bringing warm water to Totten's underbelly, causing the glacier to melt from below. This finding helps answer the question of what causes Totten to speed up some years and slow down in others. Climate change is expected to increase the intensity of winds over the Southern Ocean throughout the next century, and the new findings show that Totten Glacier will probably respond to the changing winds.

"Totten has been called the sleeping giant because it's huge and has been seen as insensitive to changes in its environment," said lead author Chad Greene, a Ph.D. candidate at the University of Texas Institute for Geophysics (UTIG). "But we've shown that if Totten is asleep, it's certainly not in a coma - we're seeing signs of responsiveness, and it might just take the wind blowing to wake it up."

The study was published Nov. 1 in the journal Science Advances. UTIG is a research unit of the UT Jackson School of Geosciences.

The team of researchers found that the glacier speeds up its flow toward the sea when winds over Antarctica's Southern Ocean are strong and pull warm water up from the deep ocean onto the continental shelf in a process called upwelling. Once the warm water reaches the coast, it circulates under the floating portion of the glacier via submarine canyons, melting the edge of the ice sheet from below. When a glacier melts, it thins, weakens and speeds up, letting more landlocked ice drain into the ocean, causing sea levels to rise.

Wind strength varies from year to year, but greenhouse gases, such as CO2, act like an amplifier to Antarctic coastal winds, boosting their intensity and allowing them to bring up warm water from the depths more frequently. This interplay between climate and wind can lead to sea level rise simply by moving water from one place in the ocean to another, said Greene - no warming of the air, or of ocean temperatures required.

Upwelling occurs when wind displaces surface water, allowing deeper and warmer water to rise up to replace it.

"It's like when you blow across a hot bowl of soup and little bits of noodles from the bottom begin to swirl around and rise to the top," said Greene.

Upwelling can have big impacts around Antarctica, where the deep waters tend to be the warmest (about 5 to 7 degrees Fahrenheit above freezing). The ocean surface is typically near freezing because it's constantly exposed to subzero air temperatures. So when wind pulls warm water up from down deep, the temperature difference experienced at the interface of the water and ice can effectively submerse the glacier in a hot bath, with some areas experiencing more than a 10-fold increase in melt rate.

The team's study complements an earlier study led by Jason Roberts, a glaciologist with the Australian Antarctic Division at the Antarctic Climate and Ecosystems Cooperative Research Center. Roberts found that when warm water melts Totten from below, it causes the base of the glacier that's usually grounded on the seafloor to float. This unpinning of the glacier can cause the glacier's flow to accelerate, adding more ice into the ocean and contributing to sea level rise.

"The remaining question was, why do the canyons beneath Totten get flushed with warm water some years and cold water other years?" said Roberts.

The new study helps answer that question by explaining how wind drives warm water beneath the glacier. By combining satellite images of the ice sheet and wind stress data from observations and computer modeling, Greene and his collaborators were able to study the chain of events that brings the warm water to Totten. That includes modeling the wind-induced upwelling at the edge of the Antarctic continental shelf, the flow of the water through submarine canyons on the continental shelf, and the water reaching Totten that causes melt and acceleration.

During the next century, winds are expected to intensify and migrate closer to the East Antarctic coast as a result of increased atmospheric greenhouse gas. This study suggests that as winds over the Southern Ocean intensify, so will Totten Glacier's contribution to global sea level rise.

"Ice sheet sensitivity to wind forcing has been hypothesized for a long time, but it takes decades of observation to show unequivocal cause and effect," said Donald Blankenship, a senior researcher at UTIG who contributed to this study and Roberts' study. "Now we're at the point where we can explicitly show the links between what happens in the atmosphere, what happens in the ocean, and what happens to the Antarctic Ice Sheet."

ICE WORLD
Wanted: a medical doctor for a cold adventure
Paris (ESA) Nov 03, 2017
Want to help humanity's exploration of our Solar System? Do you have a medical degree and are not afraid of the dark or the cold? ESA is looking for someone to spend over six months in Antarctica running research to prepare for missions to the Moon and Mars. The Italian-French Concordia research station sits on an Antarctic plateau 3200 m above sea level. So far south, the Sun does not ris ... read more

Related Links
University of Texas at Austin
Beyond the Ice Age


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

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

ICE WORLD
How Does Your Space Garden Grow

NanoRacks Deploys Second Kaber-Class Microsatellite This Week, First On-Orbit Assembly

Saudi Arabia to invest $1 billion in Virgin Galactic

Scientist devises a solar reactor to make water and oxygen from moon rocks

ICE WORLD
Arianespace to launch Embratel Star One D2

What Ever Happened to Sea Launch?

SpaceX launches Korean satellite, sticks rocket landing

Arianespace to launch Inmarsat's fifth Global Xpress satellite

ICE WORLD
Next Mars Rover Will Have 23 'Eyes'

In desert of Oman, a gateway to life on Mars

Winters leave marks on Mars' sand dunes

Winters on Mars are shaping the Red Planet's landscape

ICE WORLD
Space will see Communist loyalty: Chinese astronaut

China launches three satellites

Mars probe to carry 13 types of payload on 2020 mission

UN official commends China's role in space cooperation

ICE WORLD
New Chinese sat comms company awaits approval

Myanmar to launch own satellite system-2 in 2019: vice president

Eutelsat's Airbus-built full electric EUTELSAT 172B satellite reaches geostationary orbit

Turkey, Russia to Enhance Cooperation in the Field of Space Technologies

ICE WORLD
Liquids take a shine to terahertz radiation

Voltage-driven liquid metal fractals

Jellyfish-inspired electronic skin glows when it gets hurt

One-step 3-D printing of catalysts developed at Ames Laboratory

ICE WORLD
Overlooked Treasure: The First Evidence of Exoplanets

Scientists discover new type of deep-sea hunting called kleptopredation

'Monster' planet discovery challenges formation theory

One small doorstep for man: Cosmic mat welcomes aliens

ICE WORLD
Jupiter's X-ray auroras pulse independently

Haumea, the most peculiar of Pluto companions, has a ring around it

Ring around a dwarf planet detected

Helicopter test for Jupiter icy moons radar




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. 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