Until recently, the deepest portions of the earth have been as inaccessible to scientists as the stars in distant galaxies. Well to find out about the unknown terrain far beneath our feet, scientists are relying on earthquakes. I’m Jim Metzner, and this is the Pulse of the Planet, presented by DuPont.
We’re listening to speeded up recordings of a South American earthquake. Michael Brown is chair of the geophysics program at the University of Washington in Seattle.
“We have to use indirect remote sensing techniques like sound waves generated by earthquakes to travel through the interior of the Earth and provide us with the information of what’s down there.”
Powerful earthquakes are allowing scientists to study the earth’s most profound depths because vibrations permeate the entire planet. At laboratories around the world, with the help of sensitive instruments, the earthquake soundwaves are recorded, and their frequencies are analyzed.
“It’s possible for us to figure out the density and elastic properties of the deep interior. And we can turn these properties into maps. Think of it as a CAT scan of the Earth we can reconstruct an image of the Earth’s interior just a s X-rays through the human body can be reconstructed into a picture of internal organs.”
“We have come to a very exciting point in the earth sciences in the last few decades of being able to image the interior of the Earth at a level that really provides a fascinating perspective on how our planet works.”
We’ll hear more on using earthquakes to map the earth’s interior in future programs. Pulse of the Planet is presented by DuPont, bringing you the miracles of science, with additional support provided by the National Science Foundation. I’m Jim Metzner.