![]() ![]() 3, 2012, after weeks of minor earthquakes and bubbling natural gas that provoked community concern. The Bayou Corne sinkhole formed unexpectedly Aug. "This kind of movement may be more common than previously thought, particularly in areas with loose soil near the surface." ![]() "While horizontal surface deformations had not previously been considered a signature of sinkholes, the new study shows they can precede sinkhole formation well in advance," said Jones. Results of the study are published in the February issue of the journal Geology. These precursory surface movements covered a much larger area - about 1,640 by 1,640 feet, (500 by 500 meters) - than that of the initial sinkhole, which measured about 2 acres (1 hectare). Their analyses showed the ground surface layer deformed significantly at least a month before the collapse, moving mostly horizontally up to 10.2 inches (260 millimeters) toward where the sinkhole would later form. ![]() InSAR detects and measures very subtle deformations in Earth's surface. Researchers Cathleen Jones and Ron Blom of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., analyzed interferometric synthetic aperture radar (InSAR) imagery of the area acquired during flights of the agency's Uninhabited Airborne Vehicle Synthetic Aperture Radar (UAVSAR), which uses a C-20A jet, in June 2011 and July 2012. The data were collected as part of an ongoing NASA campaign to monitor sinking of the ground along the Louisiana Gulf Coast. Sinkholes are depressions in the ground formed when Earth surface layers collapse into caverns below. The findings suggest such radar data, if collected routinely from airborne systems or satellites, could at least in some cases foresee sinkholes before they happen, decreasing danger to people and property. On March 20, the police announced that they had broken up a major trafficking ring, arresting six Brazilians and three Colombians and seizing two airplanes and 1,086 pounds of cocaine.New analyses of NASA airborne radar data collected in 2012 reveal the radar detected indications of a huge sinkhole before it collapsed and forced evacuations near Bayou Corne, La. During a three-month crackdown last year on flights from Suriname, formerly Dutch Guiana, officials at Amsterdam's airport seized a total of 1,300 pounds of cocaine.īrazil's seizures of cocaine doubled in 1990 to 2.6 metric tons, from 1.3 tons in 1989. "Junk boats go down the river and up to Suriname without stopping," a United States official who studies the trade said. From Iquitos, Peru, or Leticia, Colombia, boats float unchecked down the Amazon system to the Atlantic Ocean, and then up the coast to the Guianas. Clandestine airstrips dot the vast wilderness. Brazil's air radar network covers only a minute fraction of its 5,450-mile border with its three cocaine-producing neighbors. Brazil was second with 5 percent.įor smugglers, Brazil's Amazon is largely an open door. Last year, 60 percent of cocaine seized in Europe came from Colombia. "Brazil is consistently in second place, after Colombia, in international embarkations of cocaine to Europe," Gerhard Neurohr, director of Interpol's cocaine desk, said in a telephone interview from France. Downstream are Brazil's Atlantic ports, which offer convenient sea and air connections to Europe and the United States. ![]() The upstream end of Brazil's Amazon Basin borders on the world's three main sources of cocaine - Bolivia, Colombia and Peru. ![]()
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