Every so often, earthquakes remind us that the solid ground beneath our feet can tremble and shake like rock jello. But there's an upside to all this shaking: Seismic waves are how we peer deep inside the Earth to map what's under the crust.
The Titan computer at the Oak Ridge National Laboratory in Tennessee was used to generate this map based on how seismic waves pass through the Earth. Red indicates slower waves and blue faster ones. New Scientist explains.
Seismic data allows us to build up a picture of the mantle -- the layer between the crust and outer core of the Earth -- by following the fate of vibrations created by earthquakes. Since they travel more slowly through viscous materials, such as molten magma, than through solid rock, analysing the seismic fallout from hundreds of earthquakes worldwide reveals inner features like mineral deposits, subterranean lakes and the movement and shape of tectonic plates.
Having mapped parts of Europe, California and China, the researchers are currently working on mapping the entire Earth down through its mantle, over 2896km deep. So what's all the way down there? Only an earthquake will tell... [Journal of Geophysical Research via New Scientist]
Picture: Ebru Bozdağ, University of Nice Sophia Antipolis, and David Pugmire, Oak Ridge National Laboratory