ESAThu, 24 Jan 2008 15:37 UTC
Ocean surface currents have long been the focus of research due to the role they play in weather, climate and transportation of pollutants, yet essential aspects of these currents remain unknown.
By employing a new technique - based on the same principle as police speed-measuring radar guns - to satellite radar data, scientists can now obtain information necessary to understand better the strength and variability of surface current regimes and their relevance for climate change.
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| ©ESA - BOOST Technologies
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| Direct measurements of upstream surface flow of the Greater Agulhas Current as obtained from ASAR Wide Swath Mode on 13, 16, 19 and 22 September 2007. The radial surface velocity is marked in the colour bar in metres per second.
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UCIThu, 24 Jan 2008 15:29 UTC
Ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland, according to a new, comprehensive study by UC Irvine and NASA scientists.
In a first-of-its-kind study, an international team led by Eric Rignot, professor of Earth system science at UCI and a scientist with NASA's Jet Propulsion Laboratory, Pasadena, Calif., estimated changes in Antarctica's ice mass between 1996 and 2006 and mapped patterns of ice loss on a glacier-by-glacier basis. They detected a sharp jump in Antarctica's ice loss, from enough ice to raise global sea level by 0.3 millimeters (.01 inches) a year in 1996, to 0.5 millimeters (.02 inches) a year in 2006.
Since we can't sample the deepest regions of the Earth, scientists watch the velocity of seismic waves as they travel through the planet to determine the composition and density of that material. Now a new study suggests that material in part of the lower mantle has unusual electronic characteristics that make sound propagate more slowly, suggesting that the material there is softer than previously thought. The results call into question the traditional techniques for understanding this region of the planet. The authors, including Alexander Goncharov from the Carnegie Institution's Geophysical Laboratory, present their results in the January 25, 2008, issue of Science.
The lower mantle extends from about 400 miles to 1800 miles (660-2900 kilometers) into Earth and sits atop the outer core. Pressures and temperatures are so brutal there that materials are changed into forms that don't exist in rocks at the planet's surface and must be studied under carefully controlled conditions in the laboratory. The pressures range from 230,000 times the atmospheric pressure at sea level (23 GPa), to 1.35 million times sea-level pressure (135 GPa). And the heat is equally extreme - from about 2,800 to 6,700 degrees Fahrenheit (1800K - 4000K).
Rebecca Morelle
BBCThu, 24 Jan 2008 14:46 UTC
Scientists believe they could be a step closer to solving the mystery of how the first birds took to the air.
A study published in the journal
Nature suggests that the key to understanding the evolution of bird flight is the angle at which a bird flaps its wings.
The US team found that birds move their wings at the same narrow angle, whether they run, fly or glide.
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| ©Unknown
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| Birds flap their wings to help propel them up steep inclines
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AFP Wed, 23 Jan 2008 17:14 UTC
JAKARTA - A strong 6.2-magnitude quake rattled the remote Indonesian island of Nias, off the west coast of Sumatra, early Wednesday, leaving one person dead and four injured, the police said.
BEIJING -- An earthquake measuring 5.5 degrees on Richter Scale hit Tibet at 2:43 Beijing Time Wednesday, according to the China Seismological Monitoring Network.
SANTIAGO -- A 5.2-magnitude earthquake hit the First Region in northern Chile Tuesday morning, according to a Seismic Monitoring Network of the University of Chile
The Arctic ice cap has shrunk by an area twice the size of France's land mass over the last two years, the Paris-based National Centre for Scientific Research (CNRS) said Wednesday.
Lake Norman, North Carolina - Nuclear reactors across the Southeast could be forced to throttle back or temporarily shut down later this year because drought is drying up the rivers and lakes that supply power plants with the awesome amounts of cooling water they need to operate.
In Cooch Behar district, the district's animal resources department sources said deaths of chicken were reported at Khalisamari of Mathabhanga-I block. ARD sources in the district said that bird deaths were reported from four blocks out of 12. These were Dinhata-I, Cooch Behar-I, Mathabhanga-I and Mekhliganj. In Haribhanga of Cooch Behar-I, carcasses of 10 migratory birds were found yesterday. The samples were sent to Kolkata.
