Microearthquake study of the broader Thessaloniki area (Northern Greece)

Abstract

A temporary network of twelve portable digital seismological stations was operated around the city of Thessaloniki (Northern Greece) for a period of 19 months (from July 2001 to April 2002 and from October 2002 to August 2003), providing data that enabled the study of the interconnection between microseismicity and active tectonics in the area. During the operation period 277 microearthquakes that were recorded in more than four stations were accurately located and 64 fault plane solutions were determined. Seismic activity is associated with ENE-WSW, E-W and ESE-WNW striking normal faults and is nearly confined to the first 15 km, thus defining the seismogenic layer in the study area. The mean orientation of the axis of maximum extension (T-axis) is NS to NNE-SSW, determined from fault plane solutions, in agreement with the regional extensional stress pattern, which strikes perpendicular to the orientation of the main WNW-ESE active faults of the area.