Plate tectonics is the theory that explains the large motions of the lithosphere. It explains how earthquakes and volcanoes are produced, and where they are located. It explains the seafloor spreading, and, in general, how the shape of the lithosphere is. However, the Earth´s interior is unreachable by direct means, and some questions about the Earth´s surface features are very difficult to answer. After 10 years of project, the EarthScope answers some of the questions geologists wondered about the North American plate.
With a wave of 400 seismometers that roll from coast to coast, seismologists have invaluable data that helps to map the deep interior of the North American plate. A more detailed image of said plate has been obtained with all the earthquakes that have been recorded during those 10 years of project, explaining some of the main features of the geology of North America. They can explain how Yellowstone seems to be created from a plume that comes from the deep mantle, o how the cold falling “drip” unloose the Colorado Plateau.
A net of GPS monitor the plate boundary between the North American and the Pacific plates, from Alaska to Mexico, providing data about the strain accumulated in that boundary. A magnitude 9 earthquake could occur in the vicinity of the state of Washington.
Finally, a borehole in the San Andreas fault explains why slip is measured in that particular point without big earthquakes occurring.
Big projects like EarthScope are necessary for a better understanding of our planet. Compared to other branches of physics, like particle physics or astronomy, geophysics is not used to that amount of money spent on it. It is striking to know that we can ‘better’ map the background microwave radiation in the Universe than the interior of our planet. Earthquakes and volcanoes are major natural hazards, and projects that give insight into the processes that lead to them should be, from my point of view, of more general interest.
Hear Richard Kerr talking about the project: podacast.
To read the full article, go here: http://www.sciencemag.org/content/340/6138/1283.summary
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