Location of the Chicxulub Crater in Yucatán. Location of the Chicxulub Crater in Yucatán.

Crater drilling shows ocean level has risen

Scientists are analyzing data produced by drilling at Chicxulub Crater last spring

The scientific expedition that went to work last spring 30 kilometers off the coast of the Yucatán peninsula to study the remnants of the Chicxulub Crater has long since left, but the results of the 65-day drilling project are now being released.

Made up of a team of 29 scientists from Mexico, the United States, Japan, Australia, Canada, China and several European countries, Expedition 364 set up in April off the Yucatán coast aboard the liftboat and drilling platform Myrtle.

The Chicxulub Crater was created by an asteroid or comet at least 10 kilometers in diameter 66 million years ago. The center of the crater, which is more than 180 kilometers in diameter, is located near the Yucatán town of Chicxulub, after which it was named.

The main source of analysis material for the scientists has been a thin length of geological strata obtained by drilling to a depth of 1.5 kilometers below the seabed.

While the central goal of the expedition was to uncover details about the demise of the dinosaurs and the evolution of life on Earth, one of the first inadvertent results obtained has been geological proof that during the last ice age the level of the ocean was far lower than what it is today.

The results were regarded as a surprise by Jaime Urrutia, a member of the scientific mission and president of the Mexican Academy of Sciences.

In the samples obtained during the drilling operations, the specialists discovered “circle-shaped structures . . . which can only be formed by carbonates dissolving, a process that can only happen in open air,” explained Urrutia.

He said that “between 18,000 and 23,000 years ago, the Yucatán peninsula was literally bigger.”

The scientists are now concluding that at the time of the asteroid’s impact the area of the crater was completely above the continental shelf, instead of being half-submerged as it now is.

The team of scientists continues to analyze the drilled samples at a laboratory at the Bremen Core Repository of the International Ocean Discovery Program (IODP) in Germany.

Source: Milenio (sp)

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