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ambience: Earthquake, time-lapse recording
We’re listening to a speeded-up recording of an earthquake. To humans, earthquakes are disasters – but on a larger scale, they’re a hint of the dynamic forces which shape our world… creating mountains and other land formations, and even maintaining the water in our oceans. I’m Jim Metzner, and this is the Pulse of the Planet.
“Earthquakes occur dominantly along the boundaries of the plates on the Earth. The plates are thin shells of crust that cover the surface, and mountain ranges occur where the crust slips past each other at boundaries. And this is what generates the earthquakes.”
Carol Raymond is a physicist at NASA’s Jet Propulsion Laboratory in Pasadena.
“Earthquakes are a natural consequence of the process of plate tectonics on the Earth. They occur where plates converge, that is, they crash together, and sometimes one plate dives under another to return into the interior of the Earth where it melts. The material that’s convecting within the Earth that’s sort of liquidy will then erupt at the mid-ocean ridges to form new crust at a plate boundary, and by this process the plates are pushed around the surface of the Earth. This creates the topography that we’re quite familiar with, and it gives us ocean basins. It also cycles lots of chemistry around on the Earth, and that governs how much water we have at the surface of the Earth, and also the amount of water in the interior of the Earth has an effect on the chemistry of the system. So our planet is somewhat unique within – at least the inner solar system – in that we have this efficient recycling process. And it’s likely to be one of the reasons that we have such a habitable environment on the Earth.”
Predicting an earthquake is a daunting task. We’ll hear how scientists are confronting this challenge in future programs. Pulse of the Planet is made possible by the National Science Foundation.
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