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Global cooling following the Chicxulub asteroid impact proven

The Chicxulub asteroid is commonly thought of as the dinosaur killer. New research conducted by Johan Vellekoop from Utrecht University and colleagues from VU University Amsterdam, and the Royal Netherlands Institute of Sea Research has proven that a global cooling event followed the impact of the Chicxulub asteroid. The study was reported in the May 12, 2014, edition of the journal Proceedings of the National Academy of Sciences.

NASA high resolution topographic map of the Yucatan Peninsula released on March 7, 2003. In the upper left portion of the peninsula, a faint arc of dark green is visible indicating the remnants of the Chicxulub impact crater.
Photo by NASA/Getty Images

The researchers examined the shape and size of sea shell fragments taken from the Brazos River between Waco, Texas and Hearne, Texas before, during, and after the Chicxulub asteroid event that occurred 66 million years ago. The analysis was done on multiple core samples. The Brazos River area was located between the Gulf of Mexico and the Western Interior Seaway at this time in history.

The boundary between the Cretaceous time frame and the Paleogene era had shells that were much more fragmented than the shells found in the layers of sediment before and after the Chicxulub asteroid impact. The fragmentation is indicative of a tsunami caused by the asteroid impact. High concentrations of iridium in the boundary layer had to have come from the asteroid because iridium is not a common element to Earth.

An analysis of the lipid content of the core samples revealed a distinct temperature decrease after the Chicxulub asteroid impact that lasted for several decades. Temperatures decreased by as much as 45 degrees Fahrenheit. The temperature decrease and the global cooling event are explained by the massive amounts of dust and water vapor that were exploded into the Earth’s atmosphere blocking sunlight by the impact of the six miles in diameter Chicxulub asteroid. This study provides extensive evidence of the cooling effects of the Chicxulub asteroid on Earth’s climate and the resulting deaths of dinosaurs and many other species.