Meteorites – Catastrophists

Music

Since the birth of our planet, has its surface transformed slowly over time, or changed rapidly? I’m Jim Metzner and this is the Pulse of the Planet. Throughout the earth’s lifetime, large meteorites have on occasion struck our world and the study of these impacts as changed the way that scientists think about the history of our planet.

“Well, one of the things that’s so interesting about impact phenomena is that they have led to a rebirth of the whole concept of catastrophism in geology. The 19th century saw endless debate and argument between catastrophists and uniformitarians.”

James Mungall is an associate professor of Geology at the University of Toronto.

“The catastrophists were people who believed that most geological processes occurred suddenly in cataclysmic events, the most recent of which was the flood recorded in the Bible, and the uniformitarians argued, and eventually won the day. They argued that the processes that you can observe happening now on the Earth, like erosion by rivers, wave action on beaches, the very slow incremental rise of mountains because of earthquakes and so on, those were the events that shaped the Earth, so that if you see a folded rock, that fold probably took hundreds of thousands of years or millions of years to form. The uniformitarian viewpoint on geological processes won out completely to the extent that by the middle of the 20th century, any proposition that sudden processes could occur was greeted with complete skepticism and ridicule. And it wasn’t until late in the 20th century that people really began to understand that although internally generated processes on Earth do conform to the uniformitarian viewpoint, the Earth is also affected by externally derived processes, like meteorite impact, that occur very suddenly.”

Pulse of the Planet was made possible by the National Science Foundation. I’m Jim Metzner.

Meteorites - Catastrophists

In the 19th century, geologists were split - did catastrophic events or slow, constant processes shape the surface of the Earth? Now, it looks like both groups might have been right.
Air Date:11/23/2009
Scientist:
Transcript:

Music

Since the birth of our planet, has its surface transformed slowly over time, or changed rapidly? I’m Jim Metzner and this is the Pulse of the Planet. Throughout the earth’s lifetime, large meteorites have on occasion struck our world and the study of these impacts as changed the way that scientists think about the history of our planet.

“Well, one of the things that’s so interesting about impact phenomena is that they have led to a rebirth of the whole concept of catastrophism in geology. The 19th century saw endless debate and argument between catastrophists and uniformitarians.”

James Mungall is an associate professor of Geology at the University of Toronto.

“The catastrophists were people who believed that most geological processes occurred suddenly in cataclysmic events, the most recent of which was the flood recorded in the Bible, and the uniformitarians argued, and eventually won the day. They argued that the processes that you can observe happening now on the Earth, like erosion by rivers, wave action on beaches, the very slow incremental rise of mountains because of earthquakes and so on, those were the events that shaped the Earth, so that if you see a folded rock, that fold probably took hundreds of thousands of years or millions of years to form. The uniformitarian viewpoint on geological processes won out completely to the extent that by the middle of the 20th century, any proposition that sudden processes could occur was greeted with complete skepticism and ridicule. And it wasn’t until late in the 20th century that people really began to understand that although internally generated processes on Earth do conform to the uniformitarian viewpoint, the Earth is also affected by externally derived processes, like meteorite impact, that occur very suddenly.”

Pulse of the Planet was made possible by the National Science Foundation. I’m Jim Metzner.