Scientists have confirmed that the Silverpit Crater, lying 700 metres beneath the southern North Sea seabed about 80 miles off the coast of Yorkshire, was formed by an asteroid or comet strike between 43 and 46 million years ago. The impact triggered a tsunami over 100 metres (330 feet) high.
Since its discovery in 2002, the 3km-wide crater and its surrounding ring of faults spanning roughly 20km have been the subject of debate. Some researchers proposed alternative explanations such as salt movement or volcanic activity. In 2009, a vote among geologists rejected the impact hypothesis.
New research published in Nature Communications, funded by the Natural Environment Research Council, provides conclusive evidence. The team, led by Dr Uisdean Nicholson of Heriot-Watt University, used seismic imaging and analysed microscopic samples from an oil well. They found 'shocked' quartz and feldspar crystals, which can only form under extreme shock pressures from an asteroid impact.
Dr Nicholson said: “Our evidence shows that a 160-metre-wide asteroid hit the seabed at a low angle from the west. Within minutes, it created a 1.5km high curtain of rock and water that then collapsed into the sea, creating a tsunami over 100 meters high.”
Professor Gareth Collins of Imperial College London, who contributed to the study, noted: “I always thought that the impact hypothesis was the simplest explanation. It is very rewarding to have finally found the silver bullet.” The crater is one of only about 33 identified beneath the ocean worldwide.
