[meteorite-list] Cataclysmic Meteor Swamped Nova Scotia 50 Million Years Ago

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:04:48 2004
Message-ID: <200205141925.MAA27620_at_zagami.jpl.nasa.gov>

http://www.canada.com/halifax/story.asp?id={9E3C189E-9295-448B-8F9B-A41188307FB6}

Cataclysmic meteor swamped Nova Scotia
By CHRIS LAMBIE
Halifax News
14 May 2002
  
A giant meteor hurtled from the sky 50 million years ago, punching a huge
crater in the ocean floor off Nova Scotia. The impact created a tidal wave
five times as high as Fenwick Tower that rolled over the entire province.

The meteor was moving at 20,000 kilometres per hour when it splashed into
the sea. About two kilometres in diameter, the space rock steamed through
the seawater and slammed into the Earth's crust 250 kilometres south of
Shelburne, creating a hole 40 kilometres across.

"If you took all the nuclear weapons on the planet, put them in one pile and
detonated them simultaneously, you wouldn't have made a hole this big," said
Gordon Oakey, a marine geophysicist at the Bedford Institute of
Oceanography.

The resulting shock wave was "horrendous," Oakey said.

It created a tidal wave, or tsunami, that engulfed the province.

"We're looking at a wall of water that would have been hundreds of metres
high," he said.

"It would have just washed over all of Nova Scotia, P.E.I. and into New
Brunswick."

Dinosaurs died off about 65 million years ago.

"So this was long after the extinction of the dinosaurs," Oakey said, adding
an earlier meteor strike on the Yucatan Peninsula probably caused their
demise.

But when the meteor splashed down near Nova Scotia, small mammals were
beginning to evolve, and the province would have been forested much as it is
now.

"Certainly, the trees would have been fairly similar at that time," he said.
"Flowering plants and grasses would have been around."

The tidal wave would have changed all that, Oakey said.

"It would have wiped down all the forests and drowned all the animal life.
It would have had a very devastating impact on biology."

Humans weren't around at the time. But if they were, they wouldn't have had
much time to see the meteor coming. "It would have been a flash in the sky."

Such a meteor may come again. But don't start building an ark in your
backyard just yet.

"Probably in the next 50 million years, we might have one or two more,"
Oakey said.

That's why space agencies around the world use telescopes to keep tabs on
asteroid bodies in our solar system, to see if any may be on track to hit
planet Earth, he said.

"Blowing it up is probably not the way to go," Oakey said. "It's probably
(more a case of) just trying to nudge it out of the way."

The hole in the Earth's crust off Shelburne is buried by as much as 1,000
metres of modern sediment.

"It's underneath a fishing bank," Oakey said. "It's no longer visible."

Scientists discovered it in the 1970s while drilling for oil. Oakey has
since studied the crater - named the Montagnais Structure, after a Quebec
First Nations band - using seismic testing and other marine survey
techniques.

Researchers have identified fewer than 100 similar large craters on Earth.

"Because of oil exploration around the world, in the last 25 years they've
been finding more and more," Oakey said.

clambie_at_hfxnews.southam.ca
Received on Tue 14 May 2002 03:25:44 PM PDT