for National Geographic Channel
In addition to its massive death toll, December's tsunami also rearranged geographic features of the Indian Ocean on a gargantuan scaleabove and below the water's surface.
Reports continue to surface of vanished islands, restructured coastlines, and uncertain shipping lanes. Geographers are responding with satellites and survey vessels to determine which areas are hardest hit. Their findings are helping and rechart maritime routes essential for the delivery of relief supplies.
David Skole and his team are using 30-meter-resolution (33 yards) satellite imagery to determine which areas were hardest hit and are most in need of help. Skole directs the Center for Global Change and Earth Observations (CGCEO) at Michigan State University. The group works in conjunction with Landsat.org, NASA, the United States Geological Survey, and other organizations.
CGCEO is concentrating much of its effort on Indonesia's Aceh Province, the heavily damaged northern region on the island of Sumatra. Even in this area that bore the brunt of the wave's destruction, the geographical impacts vary with shape of the coastline and offshore environment.
"The perspective you might get from the news is that the entire province was wiped out," Skole said. "That's not true, only about 400 to 500 square kilometers [150 to 190 square miles] were damaged along a narrow ribbon of coastline. And some pockets were worse than others."
"Unfortunately when you cross-map the damage maps with population-density maps and the locations of urban areas, you see that the areas most damaged were also the areas of high population density," he continued. "People are settling in these high-risk zones along the coastline."
Interestingly, when it comes to determining where relief efforts are most needed, satellite images are sometimes proving more reliable than reports from the scene.
"Some of these areas are remote or cut off from transportation and communication," Skole explained. "If they do have communication, people may call in and say, We need help, it's a total mess here. Well, everybody is saying that, so how do you map it?"
Skole is working to create such a relief-need map with colleagues in the Indonesian government. They're using satellite techniques they've honed over a decade-long relationship working on mapping projects related to rain forest deforestation.
"We have a global database of Landsat images from the year 2000, so we could do a before-and-after comparison," he said. "The signature of the damage is pretty striking. [We're seeing] significant coastline erosion and new islands that were once connected to the coastline."
Underwater Conditions Unknown
SOURCES AND RELATED WEB SITES