Ocean bubbling up half its oil reserves from seafloorFebruary 20th, 2009 - 3:56 pm ICT by IANS
Washington, Feb 20 (IANS) About half of the oil in the ocean bubbles up naturally from the seafloor, as if it were of no value.
Likewise, NASA satellites collect thousands of images and 1.5 terrabytes of data every year, but much of it gets passed over because no one thinks there is a use for it.
Scientists recently found black gold bubbling up from an otherwise undistinguished mass of ocean imagery.
Chuanmin Hu, optical oceanographer, University of South Florida (USF), St Petersburg, and colleagues from the National Oceanic and Atmospheric Administration (NOAA) and University of Massachusetts-Dartmouth, found that they could detect oil seeping naturally from the seafloor of the Gulf of Mexico by examining streaks amid the reflected sunlight on the ocean’s surface.
Most researchers usually discard such “sun glint” data as if they were over-exposed photos from a camera. “Significant sun glint is sometimes thought of as trash, particularly when you are looking for biomass and chlorophyll,” said Hu. “But in this case, we found treasure.”
The new technique could provide a more timely and cost-effective means to survey the ocean for oil seeps, to monitor oil slicks, and to differentiate human-induced spills from seeps.
The detection and monitoring of oil spills and seeps by satellite is not new. Visible, infrared, microwave, and radar sensors have all been used, with synthetic aperture radar (SAR) being the most popular and reliable method in recent years according to the study authors.
SAR imagery can be very expensive, the authors note, and timely, repeat coverage is not always possible, particularly in tropical regions, said an USF relief.
Using imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA’s Terra and Aqua satellites, Hu and colleagues assert, is far cheaper because the data is collected daily and provided freely by NASA, without the need for special observation requests.
Hu and colleagues obtained MODIS images for May for nine consecutive years (2000 to 2008) from NASA’s Goddard Space Flight Centre, Greenbelt. The team reviewed more than 200 images containing sun glint, and found more than 50 with extensive oil slicks.
The description of the new technique was published in January in Geophysical Research Letters.
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