S23C-2744
Synthetic PGV and PGA values for the 1969 St. Vincent Cape earthquake Ms=8.1.
Tuesday, 15 December 2015
Poster Hall (Moscone South)
Elisa Buforn1, Carmen Pro2, Jose Borges3, Carlos S Oliveira4, Marta Carranza1, Agustin Udias1, Jose Manuel Martinez Solares5, Almudena Gomis-Moreno5 and Maurizio Mattesini1, (1)Complutense University of Madrid, Madrid, Spain, (2)Universidad de Extremadura, de Fisica, Merida, Spain, (3)University of Evora, Evora, Portugal, (4)Universidade de Lisboa, Lisboa, Portugal, (5)Instituto Geografico Nacional, Madrid, Spain
Abstract:
The Cape St. Vincent region is of great seismological interest due to its tectonic complexity and the occurrence of the great 1755 Lisbon earthquake. This earthquake can repeat with catastrophic consequences. The last large shock occurred in this area on 28 February 1969 (Ms=8.1) was recorded by analogical instruments which are completely saturated. The lack of large earthquakes recorded by BB instruments limit the possibilities of seismic hazard studies in this region. In order to solve this problem, we have generated synthetic seismograms at regional distances for recent and well studied earthquakes occurred in this region, such as the 2007 (Mw=5.9) or the 2009 (Mw=5.5) events. This allows testing the earth model used for synthetic data and to generate synthetic records at regional distances for larger earthquakes. We have generated synthetic PGA values for 1969 earthquake and check them with the PGA value observed at a site of Lisbon. From the PGV values and using the empirical relations developed by Carranza et al. (2013) we obtain the predicted instrumental intensity IMM using the Wald et al (1999) relations . Comparison of them with the observed intensities for the 1969 earthquake in the Iberian Peninsula allows to validate this relation for large earthquakes at the region.
