THE KOZANI-GREVENA (GREECE) EARTHQUAKE OF MAY 13, 1995, A SEISMOLOGICAL STUDY

We present a detailed seismological study of the Kozani earthquake. We relocate the mainshock with regional data at depth of 14.2 km beneath the Vourinos massif. We compute the focal mechanism by body waveform modeling at teleseismic distance and find a normal fault striking N240 degrees and dipping 40 degrees toward the NW with a centroid depth of Il km. We installed a dense network of portable seismographs around t he epicentral region and located several hundreds of aftershocks. The main cluster of aftershock seismicity defines a plane dipping north at an angle of about 35 degrees, consistent with the main-shock mechanis m, while some seismic activity is also seen on an antithetic fault. Ou r results suggest the active fault plane to be the Deskati fault which dips at a constant angle and therefore branches on the Paleohori faul t where surface breaks were observed. We also compute 181 focal mechan isms which mostly show normal faulting. (C) 1998 Elsevier Science Ltd. All rights reserved.