Jean-Philippe Avouac: Rising Mountains and Sinking Oceans: Earthquakes That Shape the Earth

Why are the Himalaya mountains so high? Why are ocean trenches off the shores of South America and Sumatra so deep? The crust is deforming and earthquakes are at play.

Among all natural hazards, earthquakes stand out as the most difficult to assess and are a most dreadful threat, as well. One single event can cost tens- to hundreds-of-thousands of lives, and can bring down the economy of a whole country, as the recent earthquakes in Haiti, Pakistan, Sumatra, and China demonstrated. Earthquakes reflect sudden deformation events of the Earth's crust and are, therefore, manifestations of the tectonic processes that shape the Earth. Unfortunately, the factors that determine the locations, time, and size of earthquakes remain poorly understood.

Over the last few years, Jean-Philippe Avouac with his colleagues and students have been studying some of the most active plate boundaries to understand these processes. Combining modern space and traditional geological techniques and field observations, they have collected an exceptional set of observations in the Himalya, Sumatra, and South America. These observations bring new light on the physics of earthquakes and on how they relate to rising mountains and sinking oceans.

Jean-Philippe Avouac is Professor of Geology and the Director of the Tectonics Observatory at Caltech.