Wednesday, March 10, 2004

Asteroid strike 500 years ago? Anyone?.........

(Via soon to be added to stuff worth reading- Jay Manifold )

Killer Waves

"Scientists may have discovered the impact site of one big space rock that smacked into the South Pacific just a few hundred years ago. In eastern Australia, researchers have found jumbled deposits of rocks more than 130 m above sea level that they propose were left by a tsunami. That debris has been dated to about A.D. 1500—a date that matches when the Maori people inexplicably moved away from some areas of New Zealand's coast, says Stephen F. Pekar, a sedimentologist at Queens College in New York. On New Zealand's Stewart Island, two sites sport possible tsunami deposits at elevations of 150 m and 220 m, respectively"

"The source locations and heights of waves that could have lofted materials to those elevations steered the search for the impact's ground zero to beneath the sea southwest of New Zealand, says Pekar. Sure enough, he and his colleagues have discovered a crater there that's about 20 km wide and about 150 m deep. Samples of sediment taken from the seafloor southeast of the crater, but not those obtained elsewhere around the crater, contain small mineral globules called tektites, one hallmark of an extraterrestrial impact. That pattern suggests that an object may have struck from the northwest—a path that would have taken the blazing bolide over southeastern Australia, where aboriginal legends mention just such a fireball.

The rock that created tsunamis off New Zealand 500 years ago may have been around 1 km across, the researchers say. Ward and his colleagues previously estimated that a 1-km-wide asteroid slamming into the Atlantic Ocean about 600 km off North Carolina could send 130-m-tall tsunamis over beaches from Cape Hatteras to Cape Cod within 2 hours. In 8 hours, tsunamis between 30 and 50 m tall would scour European coasts. "

Glenn Reynolds, from Instapundit has this Tech Central Station column, reassessing the details of the situation.

Jay also details an excellent Proposal for an Asteroid Detection System, which makes very good sense. Problem is, if we find one soon, we won't be able to do much other than get out of the way. But for obvious reasons, the sooner we find out the better.

Then we need to work on keeping them from hitting us. This is a start, we have a long way to go................

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