A scientific debate with decades, about the origins of Silverpit Crater, in the south of the North Sea, was resolved. New evidence confirm that it was caused by the impact of an asteroid or comet about 43-46 million years ago.
A team led by Hugh Nicolsonsedimentologist at Heriot-Watt University in Edinburgh, Scotland, used seismic images, microscopic analyzes of rock fragments and numerical models to provide the most solid evidence until the date that Silverpit is one of Earth’s rare impact craters.
Their findings were presented in a published last week in Nature Communications.
A cratera Silverpit It is 700 meters deep in the North Sea, almost 130 km from the coast of Yorkshire, England. Since its discovery in 2002 that the three -kilometer diameter crater, surrounded by a 20 km wide circular failure zone, has been at the center of a lit debate between geologists.
Initial studies suggested that it was a impact crater. Scientists who at the time discovered it pointed to their central peak, circular form and concentric failures, characteristics often associated with HYPERNITY IMPACTS.
However, Alternative theories argued that the structure of the crater was caused by the movement of salt in the depths from the bottom of the crater or the collapse of the sea bottom due to volcanic activity.
In 2009, geologists submitted the formation of the crater the vote, as reported in this year of the magazine Geoscientistand most voted against the hypothesis of impact crater. New evidence proved that They were wrong.
An asteroid 160 meters in diameter reached the northern sea
The team led by Heriot-Watt University used new data from seismic images and evidence from the sea bottom to prove impact theory.
“The new seismic images have given us an unprecedented view of the crater. Samples of an oil well in the area also revealed rare quartz crystals and” shocked “feldspar at the same depth as the bottom of the crater,” says Uisdean Nicholson in.
“We had a great luck to find them – A real effort to ‘find a needle in the haystack’. They prove the hypothesis of impact crater without a doubt, as they have a structure that can only be created by extreme shock pressures. ”
Seismic map da Cratera Silverpit.
“Our evidence shows that an asteroid of 160 meters wide it reached the bottom of the sea at a low angle coming from the west. In a few minutes, he created a 1.5 km tall rock and water curtain that then collapsed in the sea, creating a tsunami over 100 meters high, ”adds Nicholson.
Gareth Collinsfrom Imperial College London, participated in the Silverpit Crater debate in 2009 and also provided numerical models for the new study. He said: “I always thought the impact hypothesis was the simplest and most consistent explanation with observations.
“It is very gratifying to have finally Found the ‘steaming weapon‘. Now we can continue with the exciting work of using the new and surprising data to learn more about how the impacts shape the planets below the surface, which is really hard to do in other planets, ”adds Collins.
“Silverpit is a rare hyperveloz impact crater and exceptionally well preserved. They are rare because Earth is a very dynamic planet – plates tectonics and erosion destroy almost every traces of most of these events, ”says Nicholson.
“There are about 200 confirmed impact craters on landand only about 33 were identified at the bottom of the ocean. We can use these findings to understand how asteroid’s impacts shaped our planet throughout history, as well as predicting what could happen if we had a collision of an asteroid in the future, ”concludes the researcher.
Silverpit confirmation as an impact crater puts it alongside structures such as Mexico, associated with dinosaur mass extinction, and A on the western coast of Africa, which was recently confirmed as a place of impact.
