HR: 0830h
AN: T51D-0198    [PDF]
TI: Moment tensor mechanisms from Iberia
AU: * Stich, D
EM: daniel@iag.ugr.es
AF: Instituto Andaluz de Geofˇsica, Campus Universitario de Cartuja s/n, Granada, 18071 Spain
AU: Morales, J
EM: morales@iag.ugr.es
AF: Instituto Andaluz de Geofˇsica, Campus Universitario de Cartuja s/n, Granada, 18071 Spain
AB: New moment tensor solutions are presented for small and moderate earthquakes in Spain, Portugal and the westernmost Mediterranean Sea for the period from 2002 to present. Moment tensor inversion, to estimate focal mechanism, depth and magnitude, is applied at the Instituto Andaluz de Geofˇsica (IAG) in a routine manner to regional earthquakes with local magnitude larger then or equal 3.5. Recent improvements of broadband network coverage contribute to relatively high rates of success: Since beginning of 2002, we could obtain valuable solutions, in the sense that moment tensor synthetic waveforms fit adequately the main characteristics of the observed seismograms, for about 50% of all events of the initial selection. Results are available on-line at http://www.ugr.es/~iag/tensor/. To date, the IAG moment tensor catalogue contains 90 solutions since 1984 and gives a relatively detailed picture of seismotectonics in the Ibero-maghrebian region, covering also low seismicity areas like intraplate Iberia. Solutions are concentrated in southern Spain and the Alboran Sea along the diffuse African-Eurasian plate boundary. These solutions reveal characteristics of the transition between the reverse faulting regime in Algeria and predominately normal faulting on the Iberian Peninsula. Further we discuss the available mechanisms for intermediate deep events, related to subcrustal tectonic processes at the plate contact.
DE: 7215 Earthquake parameters
DE: 7230 Seismicity and seismotectonics
DE: 8150 Plate boundary--general (3040)
SC: Tectonophysics [T]
MN: 2003 Fall Meeting