Geophysics

GEO The Andes Laboratory is placed in a region where the tectonic framework is controlled by the Nazca plate flat subduction under the South American plate. Sub-horizontal subduction have been occurring during at least the last 10 Ma, and although its cause is not yet well known becomes clear that it is the responsible of the profuse all magnitudes seismicity, the mountain building and the lack of Cenozoic volcanism. The Mw=8.2, April/3/1943, Ovalle earthquake, was the last very large damaging earthquake of the region, which suggest to put some attention to the seismic cycle after almost 70 yr of stress accumulation.

The laboratory low background noise (excluding the unavoidable sporadic two narrow band frequencies of oceanic microseism) is ideal to place highly sensitive seismographs able to record seismic frequencies from around 1 Hz, of local earthquakes, to very ultra-long periods of more than 100 sec of the earth normal modes vibrations excited by a large earthquake.

A broadband seismograph installed close to the Argentina-Chile boundary, make a privileged natural nexus between the two countries existent seismic networks. Therefore, useful to study seismic risk, peculiar subduction and mountain building characteristics, and topics related to global seismicity.