During the Sumatra earthquake in December 2004, followed by a deadly tsunami, experts were surprised by the magnitude of the sliding plates on each other: more than 7.5 minutes. In the same region in October 2010, a 7.8 magnitude earthquake occurred off the coast of Sumatra in the shallowest part of the subduction zone, where it was least expected, reminds the researcher University of California.
To improve knowledge, we must also densify the installation of instruments (seismometers, GPS) to the surface of the globe to monitor seismic activity and have much information to understand the phenomena, says Thorne Lay, and consider that strong earthquakes occur in areas where we do not provide.
UNDERSTANDING: Plate tectonics
Plate tectonics is a theoretical framework for understanding the face of the earth and its changes over geological time. Formulated in the early twentieth century it was fully recognized in the 1960s. It states that the Earths crust is composed of a dozen tectonic plates moving against each other. The essential activity of telluric (earthquakes and volcanism) is concentrated along plate boundaries. These boundaries can be of three kinds: they can move away from each other and along the ocean ridges, they are so divergent.