Sud Chili : tremblement de terre magnitude 8,8

              Carte de mouvements du tsunami POTENTIEL généré par le séisme au niveau du Chili.
                                     Source : West coast & Alaska tsunami warning center - NOAA
                                                un clic sur l'image mène à l'article original.

La zone où a eu lieu le séisme est proche d'une zone complexe au niveau tectonique : un point de jonction triple entre les plaques tectoniques Nazca, Antarctique et sud-américaine.

"The Chile Margin triple junction is the best modern example of the subduction of an active spreading ridge at a continental subduction zone, and thus is as close as the modern world offers to what happened along the west coast of North America over the last 20 million years of so. The geologic effects of ridge subduction can be studied relatively easily in Southern Chile because they are occurring as we look, while in California it is necessary to try to look through many million years of subsequent geologic events to try to identify the effects of ridge subduction.

Because ridge subduction represents a huge change in the thermal structure of the continental margin, it has lasting effects on the structure of the crust where it has taken place. These changes might influence such improtant modern phenomena as earthquake seismicity. If we can gain insights in to the geological and geophysical evolution of continental margins by studying active modern examples such as Southern Chile where spreading ridge subduction is taking place, we might be able to better understand the evolution of the San Andreas fault and other regions where similar events have occurred in the past."