4 th International Conference on Earthquake Geotechnical Engineering June 25-28, 2007 Paper No. 1609 SEISMICALLY CAPABLE FAULTS IN GREECE AND THEIR USE IN SEISMIC HAZARD ASSESSMENT Spyros PAVLIDES 1 , Sotiris VALKANIOTIS 2 and Alexandros CHATZIPETROS 3 ABSTRACT This paper examines the distribution of the main seismically capable faults of Greece and the broader Aegean region, as well as their usefulness in seismic hazard assessment. The geological faults have been classified into two distinct categories, depending on their location: mainland faults and offshore faults. Faults in these categories present various differences, as well as similarities. Mainland faults, although not as large as the offshore ones, are the most hazardous ones, as they may affect directly structures and infrastructures. The characterization of faults has been done based on historical, geological, geomorphological and geometrical criteria. Keywords: Active faults, Greece, Aegean, Surface ruptures, Seismic Hazard INTRODUCTION One of the main considerations to be taken into account when designing a structure is the probable effects of a near- or far- field earthquake. The intensity of the earthquake in any given area, hence the effects on structures and infrastructures, is a direct consequence of the following factors: 1. The physical properties of the foundation soil 2. The distance and depth of the earthquake epicentre 3. The proximity to any geological faults, even ones that have not been activated during the earthquake. The latter factor holds a very significant role in seismic behaviour of structures, but its effect has been largely underestimated in recent studies, while there is no technical experience and technology to prevent earthquake damage to buildings built across faults. It is important to note that, it is difficult to assign a given earthquake to a particular fault even with modern data. For historical events morphotectonic and other geological data are important, but mainly clear literature evidence and especially palaeoseismological proof are crucial. There are plenty of examples world-wide and within the Aegean Region. In this study we use mainly geological criteria in association with literature information of historical earthquakes, archaeoseismological and geodetic evidence, in order to characterize active or possibly active faults, that is capable faults and to map them. This can be considered as the first step in seismic hazard assessment. In this paper we present the recently compiled and constantly updated map of active and possibly active faults in Greece, as well as the main points of the fault related seismic hazard assessment (SHA) that should be taken into account when designing a structure. 1 Professor, Department of Geology, Aristotle University, 54124, Thessaloniki, Greece, email: pavlides@geo.auth.gr 2 Geologist MSc, Department of Geology, Aristotle University, 54124, Thessaloniki, Greece 3 Geologist PhD, Department of Geology, Aristotle University, 54124, Thessaloniki, Greece