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The Earth’s surface is covered by 70 per cent water so any asteroid crashing into the Earth, is likely to splash down somewhere in the ocean. The potential result would be a huge tsunami wave, spreading out from the impact site like the ripples caused by a rock thrown into a pond. These waves would most likely inundate heavily populated coastal areas.
Scientists at University of California, Santa Cruz, USA, used a computer simulation of an asteroid impact with information known about 1950 DA. The findings from the simulation are reported in the June issue of the Geophysical Journal International.
The asteroid known as 1950 DA is a huge space rock over a kilometre in diameter that has a one in 300 chance of hitting the Earth the night before St. Patrick’s Day, 2880. Even though the probability of a direct hit is pretty small, over the long timescales of Earth's history, asteroids this size and larger have periodically hammered the planet, sometimes with catastrophic effects. For example, a collision into North Mexico, 65 million years, ended the reign of the dinosaurs. This event is known as the Cretaceous-Tertiary (K-T) extinction.
For the simulation, researchers chose an impact site consistent with the orientation of the Earth at the time of the predicted encounter, in the Atlantic Ocean about 576 kilometres from the U.S. coast, the result summaries follow.
The impact vaporizes the asteroid and blows a cavity in the ocean down to the seafloor, at this point 17.6 kilometres across and about five kilometres deep. The blast excavates some of the seafloor. Water then rushes back in to fill the cavity, and a ring of waves spreads out in all directions.
The impact creates a tsunami almost the same height as the diameter as the crater. The waves propagate all through the Atlantic Ocean and the Caribbean. The coastal areas closest to the impact get hit by the largest waves, four hours after impact the entire East Coast has experienced waves at least 60 metres high, 8 hours the waves to reach Europe at heights over 15 meters.
The results go to help scientists to better understand the potential hazards of asteroid impacts and interpret events that appear in the Earth’s geological record.
More info: Asteroid 1950 DA
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