Various: A 180-km-diameter crater in Mexico called Chicxulub was formed by an object 10 km across that caused a 100-million-megaton explosion when it hit Earth. Until now, that event had generally been believed to have caused the extinction of the dinosaurs.
A bigger crater, named Shiva, which was found by Sankar Chatterjee of Texas Tech University, is 500 km across. The explosion that caused it may have been 100 times the size of the one that created Chicxulub.
Chatterjee presented his latest findings on Shiva to the annual meeting of the Geological Society of America in Portland, Oregon, on 18 October.
The late era of the dinosaurs was a period in which volcanic activity was frequent and common, yet the dinosaurs were thriving until the two objects hit Earth.
According to the Economist:
The picture that is emerging, then, is of a strange set of coincidences. First, two of the biggest impacts in history happened within 300,000 years of each other—a geological eyeblink. Second, they coincided with one of the largest periods of vulcanicity in the past billion years. Third, one of them just happened to strike where these volcanoes were active. Or, to put it another way, what really killed the dinosaurs was a string of the most atrocious bad luck.
Related Links
I am become Death, destroyer of worlds The Economist
Dinosaurs 'could have been wiped out by 25 mile wide meteor' The Daily Telegraph
Giant impact near India—not Mexico—may have doomed dinosaurs GSA
The significance of the contemporaneous Shiva impact structure and Deccan volcanism at the KT boundary
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