Meteorites – Deep Impact

Music
Ambience Underwater Quake

In our last episode, eons ago, the earth had just been hit by a meteorite the size of Mount Everest. Following a tremendous flash, a blast of incinerating heat and a cataclysmic shock wave, our story continues. I’m Jim Metzner and this is the Pulse of the Planet. Professor James Mungall teaches geology at the University of Toronto. He’s been studying the site of an ancient meteorite crash in Sudbury, Ontario, Canada, for clues to what happened there two billion years ago.

“And immediately following the passage of that shockwave, which is all over in a matter of a few seconds, you’ve got a tremendous volume of very, very hot material that wants to get out. And so, there’s a very large pressure produced just by the heat of this material. So, you get a fireball that goes up, like in a nuclear explosion. And you have a tremendous outward pressure within the crater, which causes what’s called a transient cavity to form. The transient cavity is a hole in the ground, perhaps even 50 kilometers deep, and about 100 kilometers in diameter shaped like a biglike a soup bowl. And so, a minute after the impact occurs, this bowl has opened up in the surface of the Earth. That transient cavity collapses, and so, the ground rushes back up to fill the space. It collapses in from the sides. It rebounds from the bottom. And after another few minutes what you’re left with isis a much larger diameter crater, which is only, perhaps, five kilometers deep. So, then you have a depression that’s shaped like a dinner plate. And that larger final crater, which was 200 to 300 kilometers in diameter, is floored by a pool of shock-melted rock. It’s as deep as the ocean, filled with melted rock.”

We’ll hear more on the Sudbury impact in future programs. Pulse of the Planet is made possible by the National Science Foundation. I’m Jim Metzner.

Meteorites - Deep Impact

The nightmare continues with a shockwave that's got the force of a nuclear explosion.
Air Date:11/05/2009
Scientist:
Transcript:

Music
Ambience Underwater Quake

In our last episode, eons ago, the earth had just been hit by a meteorite the size of Mount Everest. Following a tremendous flash, a blast of incinerating heat and a cataclysmic shock wave, our story continues. I’m Jim Metzner and this is the Pulse of the Planet. Professor James Mungall teaches geology at the University of Toronto. He’s been studying the site of an ancient meteorite crash in Sudbury, Ontario, Canada, for clues to what happened there two billion years ago.

“And immediately following the passage of that shockwave, which is all over in a matter of a few seconds, you’ve got a tremendous volume of very, very hot material that wants to get out. And so, there’s a very large pressure produced just by the heat of this material. So, you get a fireball that goes up, like in a nuclear explosion. And you have a tremendous outward pressure within the crater, which causes what’s called a transient cavity to form. The transient cavity is a hole in the ground, perhaps even 50 kilometers deep, and about 100 kilometers in diameter shaped like a biglike a soup bowl. And so, a minute after the impact occurs, this bowl has opened up in the surface of the Earth. That transient cavity collapses, and so, the ground rushes back up to fill the space. It collapses in from the sides. It rebounds from the bottom. And after another few minutes what you’re left with isis a much larger diameter crater, which is only, perhaps, five kilometers deep. So, then you have a depression that’s shaped like a dinner plate. And that larger final crater, which was 200 to 300 kilometers in diameter, is floored by a pool of shock-melted rock. It’s as deep as the ocean, filled with melted rock.”

We’ll hear more on the Sudbury impact in future programs. Pulse of the Planet is made possible by the National Science Foundation. I’m Jim Metzner.