(Press-News.org) Researchers from the Alfred Wegener Institute in Germany have used satellite data to map elevation and elevation changes in both Greenland and Antarctica. The new maps are the most complete published to date, from a single satellite mission. They also show the ice sheets are losing volume at an unprecedented rate of about 500 cubic kilometres per year. The results are published today in The Cryosphere, an open access journal of the European Geosciences Union (EGU).
"The new elevation maps are snapshots of the current state of the ice sheets," says lead-author Veit Helm of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), in Bremerhaven, Germany. The snapshots are very accurate, to just a few metres in height, and cover close to 16 million km2 of the area of the ice sheets. "This is 500,000 square kilometres more than any previous elevation model from altimetry – about the size of Spain."
Satellite altimetry missions measure height by bouncing radar or laser pulses off the surface of the ice sheets and surrounding water. The team derived the maps, which show how height differs across each of the ice sheets, using just over a year's worth of data collected in 2012 by the altimeter on board the European Space Agency satellite CryoSat-2. These 'digital elevation models' incorporate a total of 7.5 million elevation measurements for Greenland and 61 million for Antarctica.
In addition to showing the highs and lows of the ice sheets at present, the study also highlights how the elevation has changed over the 2011-2014 period. Ice sheets gain mass through snowfall and lose it due to melting and accelerating glaciers, which carry ice from the interior of the ice sheet to the ocean. The researchers say it's important to understand how ice thickness across Greenland and Antarctica has changed to model ice movements, and find out just how much ice sheets contribute to sea level rise.
The team derived the elevation change maps using a staggering 200 million data points for Antarctica and 14.3 million for Greenland collected by CryoSat-2 over the three-year period. The maps published in The Cryosphere reveal that Greenland alone is reducing in volume by about 375 cubic kilometres per year. The two ice sheets combined are thinning at a rate of 500 cubic kilometres per year, the highest rate observed since altimetry satellite records began about 20 years ago. The researchers say the ice-sheets annual contribution to sea level rise doubled since 2009.
"Since 2009, the volume loss in Greenland has increased by a factor of about 2, and in the West Antarctic Ice Sheet by a factor of 3," says AWI glaciologist Angelika Humbert, another of the study's authors. Both the West Antarctic Ice Sheet and the Antarctic Peninsula, on the far west of the continent, are rapidly losing volume. By contrast, East Antarctica is gaining volume, though at a moderate rate that doesn't compensate the losses on the other side of the continent.
The areas where the researchers detected the largest elevation changes were Jakobshavn Isbrae (Jakobshavn Glacier) in Greenland – recently found to be moving ice into the ocean faster than any other ice-sheet glacier – and Pine Island Glacier (PIG) in Antarctica. The new study confirms that PIG, like other glaciers in the West Antarctic, has been thinning rapidly in recent years.
The researchers highlight the role of CryoSat-2 and its radar altimeter (also known as SIRAL) in producing the height maps, particularly in regions where the surface slopes steeply and elevation changes are more pronounced. "These areas can be difficult to measure, but SIRAL enabled us to continuously observe the surface of the ice sheets with high precision and dense coverage, better than any previous system," says Helm.
INFORMATION:
Please mention the name of the publication (The Cryosphere) if reporting on this story and, if reporting online, include a link to the paper (TBA) or to the journal website (http://www.the-cryosphere.net).
Highs and lows: Height changes in the ice sheets mapped
2014-08-20
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Turning waste from rice, parsley and other foods into biodegradable plastic
2014-08-20
Your chairs, synthetic rugs and plastic bags could one day be made out of cocoa, rice and vegetable waste rather than petroleum, scientists are now reporting. The novel process they developed and their results, which could help the world deal with its agricultural and plastic waste problems, appear in the ACS journal Macromolecules.
Athanassia Athanassiou, Ilker S. Bayer and colleagues at the Italian Institute of Technology point out that plastic's popularity is constantly growing. In 2012, its production reached 288 million tons worldwide, but its ubiquity comes at a ...
Celebrating 100 years of crystallography
2014-08-20
To commemorate the 100th anniversary of a revolutionary technique that underpins much of modern science, Chemical & Engineering News (C&EN) magazine last week released a special edition on X-ray crystallography — its past, present and a tantalizing glimpse of its future. C&EN is the weekly news magazine of the American Chemical Society (ACS), the world's largest scientific society.
The technique got its start when German physicist Max von Laue published the first paper on X-ray diffraction from a crystal in 1912. In the century following von Laue's discovery, which was ...
Teen sleeplessness piles on risk for obesity
2014-08-20
Teenagers who don't get enough sleep may wake up to worse consequences than nodding off during chemistry class. According to new research, risk of being obese by age 21 was 20 percent higher among 16-year-olds who got less than six hours of sleep a night, compared with their peers who slumbered more than eight hours. (The Centers for Disease Control and Prevention recommends nine to ten hours of sleep for teenagers.)
Researchers at the Mailman School of Public Health at Columbia University and the University of North Carolina Gillings School of Public Health are the first ...
Severe infections with hospitalization after prostate biopsy rising in Sweden
2014-08-20
New York, NY, August 20, 2014 – Transrectal ultrasound guided biopsy is the gold standard for detecting prostate cancer, but international reports have suggested that the number of risks associated with the procedure is increasing. In a new nationwide population-based study, Swedish researchers found that six percent of men filled a prescription for antibiotics for a urinary tract infection within 30 days after having a prostate biopsy, with a twofold increase in hospital admissions over five years, reports The Journal of Urology®.
Earlier studies reported serious adverse ...
Salt, pink diamonds and DNA: 5 surprising facts about crystals (video)
2014-08-20
WASHINGTON, August 11, 2014 — Many people think of crystals as little more than sparkly things behind glass cases in museums. But crystals are everywhere, from the dinner table to the human body. Because 2014 is the International Year of Crystallography, Reactions is celebrating with a video highlighting five surprising facts about crystals. The video is available at: http://youtu.be/urq8SuPMZ_w.
Have a favorite crystal? Our friends at Chemical & Engineering News want to hear about it! Vote at http://cen.acs.org/favecrystals, and while you're there, you can learn a lot ...
Signs of deforestation in Brazil
2014-08-20
Multiple fires are visible in in this image of the Para and Mato Grosso states of Brazil. Many of these were most likely intentionally set in order to deforest the land. Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use. The herringbone-patterned tan lines cutting through the dark green of the Amazon Rainforest in the middle of the image are evidence of deforestation in the Brazilian state of Pará. The deforestation ...
Newborn screening expansion offers early diagnosis and treatment to infants with SCID
2014-08-20
WORCESTER, MA – Using population-based screening outcomes of approximately 3 million infants, a team of scientists across 14 states, including four researchers at the University of Massachusetts Medical School, have shown that newborn screening for severe combined immunodeficiency (SCID) can be successfully implemented across public health newborn screening programs. Data from 11 newborn screening programs published in the Aug. 20 issue of the Journal of the American Medical Association (JAMA) showed the rate of SCID in newborns is higher than previously thought and believed ...
Lyme disease risk is year-round in Northwest California, according to new study
2014-08-20
SILICON VALLEY, Calif., August 19, 2014 -- Bay Area Lyme Foundation, which aims to make Lyme disease easy to diagnose and simple to cure, applauds new research published in an upcoming issue of the Elsevier peer review journal Ticks and Tick-borne Diseases. The findings show that ticks that carry Lyme disease in Northwest California are active throughout the year, making the threat of Lyme disease year-round. The research was conducted by researchers at California Department of Public Health (CDPH) Vector-borne Disease Section and University of California, Berkeley (UC-B).
"These ...
NASA sees Tropical Storm Lowell's tough south side
2014-08-20
VIDEO:
NOAA's GOES-14 satellite was brought out of storage and put in Super Rapid Scan Operations for GOES-R mode and data of Tropical Storm Lowell from Aug. 19 was animated....
Click here for more information.
The south side of Tropical Storm Lowell appears to be its toughest side. That is, the side with the strongest thunderstorms, according to satellite imagery from NOAA's GOES-14 and NASA-NOAA's Suomi NPP satellites.
NOAA took its GOES-14 satellite out of storage to simulate ...
Gene therapy protects mice from lethal heart condition, MU researchers find
2014-08-20
COLUMBIA, Mo. — A new gene therapy developed by researchers at the University of Missouri School of Medicine has been shown to protect mice from a life-threatening heart condition caused by muscular dystrophy.
"This is a new therapeutic avenue," said Yi Lai, Ph.D., the leading author of the study and assistant research professor in the MU School of Medicine's Department of Molecular Microbiology and Immunology. "This is just a first step, but we hope this could lead to a treatment for people with this devastating heart condition, which is a leading cause of death for ...