Chile is one of the most seismically active countries in the world with a M〉8 earthquake occurring approximately every ten years. The recent 27th February 2010 (Mw=8.8) earthquake released the energy accumulated in the
Concepción-Constitución seismic gap, contained since the last 1835 earthquake. The hypocenter was located at the subduction interface of the Nazca plate under the South American plate, near the coast of Talcahuano, at a depth of 30 km. The rupture area extended approximately for 450 km long, from the Arauco Peninsula northwards to Pichilemu. Hundreds of aftershocks have taken place in the rupture area, the largest of which was the Pichilemu M=6.9 earthquake on 11th March. A volcano-surrounding network was installed in Llaima and Villarrica volcanoes in Southern Chile in November, 2009. Each network comprises one
Broad Band station, one “Ocean” Bottom Station and three Short-Period stations arranged in a circular disposition. The seismological data recording at the two volcanoes is still ongoing until April 2011. Data examples and first results from the analysis of the data recorded from
November, 2009 until April, 2010 are presented. The mainshock, foreshocks and aftershocks were retrieved, and are being separated from the local seismicity in the records. During the same time frame, volcanic events are identified to characterize the volcano seismicity at Llaima and Villarrica volcanoes, to correlate this activity
with degassing emissions (SO2) measured with mini-DOAS. Any influence of the Maule earthquake on the volcanoes behaviour is also investigated based on the seismic records.
Conference or Workshop Item