News / Science & Technology

    Warming Oceans Cause Bulk of Antarctic Ice Loss

    This photo shows the ice front of Venable Ice Shelf, West Antarctica, in October 2008. (NASA/JPL-Caltech/UC Irvine)
    This photo shows the ice front of Venable Ice Shelf, West Antarctica, in October 2008. (NASA/JPL-Caltech/UC Irvine)

    Related Articles

    Scientists Reconstruct 2,000 Years of Temperature Change

    New study says world-wide warming trend began at end of 19th century and that past 30 years warmest in 1,400 years

    Japanese Researchers Find Possible Lost Continent in Atlantic Ocean

    Granite found on seabed, suggesting a continent may have once existed off coast of Brazil
    Most of the loss Antarctic ice is not caused by icebergs falling apart into the sea, but instead by warmer ocean waters underneath the massive ice shelves causing melting, according to a new study by NASA and university researchers.

    The study found that so-called basal melt accounted for 55 percent of all ice shelf mass loss from 2003 to 2008.  Using reconstructions of ice accumulation as well as satellite and aircraft readings of ice thickness and changes in elevations, scientists were able to compare the speed of ice shelf melt versus that of calving, or the splitting of icebergs.

    "The traditional view on Antarctic mass loss is it is almost entirely controlled by iceberg calving," said Eric Rignot of NASA's Jet Propulsion Laboratory in Pasadena, Calif.

    "Our study shows melting from below by the ocean waters is larger, and this should change our perspective on the evolution of the ice sheet in a warming climate," said Rignot, lead author of the study to be published in the June 14 issue of the journal Science.

    According to NASA, the Antarctic ice shelves lost 1,325 trillion kilograms of ice per year in 2003 to 2008 through basal melt, while calving accounted for 1,089 trillion kilograms of mass loss each year.

    Rates of basal melt of Antarctic ice shelves (melting of the shelves from underneath) overlaid on a 2009 mosaic of Antarctica created from data from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Terra and Aqua spaceRates of basal melt of Antarctic ice shelves (melting of the shelves from underneath) overlaid on a 2009 mosaic of Antarctica created from data from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Terra and Aqua space
    x
    Rates of basal melt of Antarctic ice shelves (melting of the shelves from underneath) overlaid on a 2009 mosaic of Antarctica created from data from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Terra and Aqua space
    Rates of basal melt of Antarctic ice shelves (melting of the shelves from underneath) overlaid on a 2009 mosaic of Antarctica created from data from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Terra and Aqua space
    Determining how the ice is melting will help scientists improve models on how the Antarctic ice sheet will evolve with warming ocean temperatures, including how it could contribute to sea level rise and changing ocean circulation.

    "Changes in basal melting are helping to change the properties of Antarctic bottom water, which is one component of the ocean's overturning circulation," said another study author, Stan Jacobs, an oceanographer at Columbia University's Lamont-Doherty Earth Observatory in Palisades, New York. "In some areas it also impacts ecosystems by driving coastal upwelling, which brings up micronutrients like iron that fuel persistent plankton blooms in the summer."

    The rate of basal melting varies around the continent. The three giant ice shelves - Ross, Filchner and Ronne, which make up two-thirds of the total Antarctic ice shelf area - accounted for only 15 percent of basal melting. Smaller ice shelves produced half of the basal melt over the period studied, NASA said.

    "Ice shelf melt doesn't necessarily mean an ice shelf is decaying. It can be compensated by the ice flow from the continent," Rignot said. "But in a number of places around Antarctica, ice shelves are melting too fast, and a consequence of that is glaciers, and the entire continent, are changing as well."

    You May Like

    In Britain, The Sun Still Doesn’t Shine

    Invoking Spitfires and Merlin, Leave voters insist country can be great again, following surprising 'Brexit' vote last week

    Double Wave of Suicide Bombings Puts Lebanon, Refugees on Edge

    Following suicide bombings in Christian town of Al-Qaa, on Lebanon's northeast border with Syria, fears of further bombings have risen

    US Senators Warned on Zika After Failing to Pass Funding

    Zika threats and challenges, as well as issues of contraception and vaccines, spelled out as lawmakers point fingers

    This forum has been closed.
    Comment Sorting
    Comments
         
    by: Roger Halstead from: Midland MI
    June 21, 2013 12:03 AM
    So where does the added heat come from to melt this ice? It takes 100 calories to melt 1 cc of ice while that same calorie will warm 1 cc of water 1 degree. Melting ice: Natures air conditioner!

    by: Kitagawa Keikoh from: Daikanyama, JPN
    June 14, 2013 7:56 PM
    What's wrong with climate change and melting ice?
    It is one of the natural phenomena.
    All we have to do is adjusting our life to current climate. We are not able to change our climate, and that means reducing CO2 has nothing with climate change.

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Slow Rebuilding Amid Boko Haram Destruction in Nigeria’s Northeasti
    X
    June 29, 2016 6:15 PM
    Military operations have chased Boko Haram out of towns and cities in Nigeria’s northeast since early last year. But it is only recently that people have begun returning to their homes in Adamawa state, near the border with Cameroon, to try to rebuild their lives. For VOA, Chris Stein traveled to the area and has this report.
    Video

    Video Slow Rebuilding Amid Boko Haram Destruction in Nigeria’s Northeast

    Military operations have chased Boko Haram out of towns and cities in Nigeria’s northeast since early last year. But it is only recently that people have begun returning to their homes in Adamawa state, near the border with Cameroon, to try to rebuild their lives. For VOA, Chris Stein traveled to the area and has this report.
    Video

    Video Clinton Leads Trump, But Many Voters Don't Like Either

    In the U.S. presidential race, most recent polls show Democrat Hillary Clinton with a steady lead over Republican Donald Trump as both presumptive party nominees prepare for their party conventions next month. Trump’s disapproval ratings have risen in some recent surveys, but Clinton also suffers from high negative ratings, suggesting both candidates have a lot of work to do to improve their images before the November election. VOA National correspondent Jim Malone has more from Washington.
    Video

    Video New US Ambassador to Somalia Faces Heavy Challenges

    The new U.S. envoy to Somalia, who was sworn into office Monday, will be the first American ambassador to that nation in 25 years. He will take up his post as Somalia faces a number of crucial issues, including insecurity, an upcoming election, and the potential closure of the Dadaab refugee camp in Kenya. VOA’s Jill Craig asked Somalis living in Kenya’s capital city Nairobi how they feel about the U.S. finally installing a new ambassador.
    Video

    Video At National Zoo, Captivating Animal Sculptures Illustrate Tragedy of Ocean Pollution

    The National Zoo in Washington, D.C., is home to about 1,800 animals, representing 300 species. But throughout the summer, visitors can also see other kinds of creatures there. They are larger-than-life animal sculptures that speak volumes about a global issue — the massive plastic pollution in our oceans. VOA's June Soh takes us to the zoo's special exhibit, called Washed Ashore: Art to Save the Sea.
    Video

    Video Baghdad Bikers Defy War with a Roar

    Baghdad is a city of contradictions. War is a constant. Explosions and kidnappings are part of daily life. But the Iraqi capital remains a thriving city, even if a little beat up. VOA's Sharon Behn reports on how some in Baghdad are defying the stereotype of a nation at war by pursuing a lifestyle known for its iconic symbols of rebellion: motorbikes, leather jackets and roaring engines.
    Video

    Video Melting Pot of Immigrants Working to Restore US Capitol Dome

    The American Iron Works company is one of the firms working to renovate the iconic U.S. Capitol Dome. The company employs immigrants of many different cultural and national backgrounds. VOA’s Arman Tarjimanyan has more.
    Video

    Video Testing Bamboo as Building Material

    For thousands of years various species of bamboo - one of the world's most versatile plants - have been used for diverse purposes ranging from food and medicine to textiles and construction. But its use on a large scale is hampered because it's not manufactured to specific standards but grown in the ground. A University of Pittsburgh professor is on track to changing that. VOA’s George Putic reports.
    Video

    Video Orphanage in Iraqi City Houses Kids Who Lost their Parents to Attacks by IS

    An orphanage in Iraqi Kurdistan has become home to scores of Yazidi children who lost their parents after Islamic State militants took over Sinjar in Iraq’s Nineveh Province in 2014. Iraqi Kurdish forces backed by the U.S. airstrikes have since recaptured Sinjar but the need for the care provided by the orphanage continues. VOA’s Kawa Omar filed this report narrated by Rob Raffaele.
    Video

    Video Re-Opening Old Wounds in a Bullet-Riddled Cultural Landmark

    A cultural landmark before Lebanon’s civil war transformed it into a nest of snipers, Beirut’s ‘Yellow House’ is once again set to play a crucial role in the city.  Built in a neo-Ottoman style in the 1920s, in September it is set to be re-opened as a ‘memory museum’ - its bullet-riddled walls and bunkered positions overlooking the city’s notorious ‘Green Line’ maintained for posterity. John Owens reports from Beirut.
    Video

    Video Brexit Resounds in US Presidential Contest

    Britain’s decision to leave the European Union is resounding in America’s presidential race. As VOA’s Michael Bowman reports, Republican presumptive nominee Donald Trump sees Britain’s move as an affirmation of his campaign’s core messages, while Democrat Hillary Clinton sees the episode as further evidence that Trump is unfit to be president.
    Video

    Video NASA Juno Spacecraft, Nearing Jupiter, to Shed Light on Gas Giant

    After a five-year journey, the spacecraft Juno is nearing its destination, the giant planet Jupiter, where it will enter orbit and start sending data back July 4th. As Mike O'Sullivan reports from Pasadena, California, the craft will pierce the veil of Jupiter's dense cloud cover to reveal its mysteries.
    Video

    Video Orlando Shooting Changes Debate on Gun Control

    It’s been nearly two weeks since the largest mass shooting ever in the United States. Despite public calls for tighter gun control laws, Congress is at an impasse. Democratic lawmakers resorted to a 1960s civil rights tactic to portray their frustration. VOA’s Carolyn Presutti explains how the Orlando, Florida shooting is changing the debate.

    Special Report

    Adrift The Invisible African Diaspora