Wednesday, March 11, 2009

Terrestrial Impact Craters :Chicxulub, Yucatan Peninsula, Mexico

Chicxulub Chicxulub, Yucatan Peninsula, Mexico
21°20'N, 89°30'W; diameter: 170 km; age: 64.98 million years This three-dimensional map of local gravity and magnetic field variations shows a multiringed structure called Chicxulub named after a village located near its center. The impact basin is buried by several hundred meters of sediment, hiding it from view. This image shows the basin viewed obliquely from approximately 60° above the surface looking north, with artificial lighting from the south. The image covers 88 to 90.5° west longitude and 19.5 to 22.5° north latitude. NASA scientists believe that an asteroid 10 to 20 kilometers (6 to 12 miles) in diameter produced this impact basin. The asteroid hit a geologically unique, sulfur-rich region of the Yucatan Peninsula and kicked up billions of tons of sulfur and other materials into the atmosphere. Darkness prevailed for about half a year after the collision. This caused global temperatures to plunge near freezing. Half of the species on Earth became extinct including the dinosaurs. (Image courtesy of V. L. Sharpton, LPI)

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