Today’s Washington Post carries this fascinating story about a cataclysm that hit a little bit too close to home about 35 million years ago.
EASTVILLE, Va. A white fireball two miles across thunders from the sky at 30,000 mph and crashes into the ocean off the Virginia coast. The impact vaporizes billions of tons of water, rips a hole in the sea floor six miles deep and fractures the bedrock far into the Earth.
The splash is 30 miles high. Debris is lofted over the horizon and rains down on an area of 3 million square miles, as distant as the Antarctic. Towering tsunamis surge toward the Blue Ridge Mountains.
Nearby life — ferocious-looking sea creatures and dog-sized proto-horses along the tropical shoreline — is blasted and then swept into the abyss by the boiling ocean. A calamity of unimaginable scale, it is probably the most stupendous geological event ever on the East Coast.
For more than a decade, geologists have believed that a gigantic object, an asteroid or a comet, struck the Earth north of Norfolk about 35 million years ago in a cataclysmic occurrence that left behind a 53-mile-wide, long-buried crater.
Were something like this to happen today, it would devastate the metropolitan areas of Washington, Baltimore, and Norfolk/Virginia Beach, and populations as far west as the Blue Ridge Mountains. The East Coast itself would be a disaster area on a scale that would make Hurricane Katrina look like a picnic. This is, course, not the only place on the planet where fire and rock have rained down from the skies:
There are scores of known impact sites around the world and millions more on planets and moons across the solar system. The one near Norfolk is Earth’s seventh-largest site and the biggest in the United States.
The question is, could something like this happen again ? Of course it could, and to believe otherwise is to underestimate the true scope of the universe we live in.
Two years ago, a pair of California scholars, Steven N. Ward and Erik Asphaug, published a paper about the potential impact of an asteroid that scientists think has a minute possibility of striking Earth in 2880.
The asteroid, called 1950 DA, is about a half-mile in diameter. The two men calculated that if it struck the sea at 40,000 mph, 370 miles off the East Coast, it would blow an 11-mile hole in the sea floor and within two hours would send 300-foot tsunamis crashing against the coast from Cape Cod, Mass., to Cape Hatteras, N.C.
The chances of impact are highly remote, and their paper was just “a focus of thought,” the authors wrote. “Humanity lives with a calculus of infinite devastation times infinitesimal probability.”
Fortunately or not, none of us will be around in 2880 to find out if 1950 DA is “the big one” or another near miss.
