Seismicity, normal faulting, and the geomorphological development of the Gulf of Corinth (Greece): the Corinth earthquakes of February and March 1981

J. Jackson (1) , J. Gagnepain (2) , G. Houseman (1) , G.C.P. King (1) , P. Papadimitriou (2) , C. Soufleris (1) , J. Virieux (2)

1 Bullard Lboratories
2 IPG Paris - Institut de Physique du Globe de Paris

Three major destructive earthquakes of M~ 6.7, 6.4, 6.4 occurred in the eastern part of the Gulf of Corinth in February' and March 1981. Associated normal faulting was observed on both the north and the south sides of the (iulf. Examination of teleseismic, local seismic, surface faulting and geomorpbological data sugge.,ts that the first and second of these shocks activated major north-dipping normal faults. These faults control the topography and bath?metr> and are related to the recent uplift and subsidence of the coastline. It is probable that the first earthquake occurred on a fault which outcrops underwater and the second on a fault which is ~isible on land. It appears that the third shock activated an antithetic normal fault dipping southwards on the north side of the Gulf and that the overall structure of the Gulf of Corinth graben is asymmetric. The northern antithetic fault clearly demonstrates the geomorphological changes associated with developing young normal faulting. In addition, we suggest that observations of recent coastline movement provide a powerful tool for identifying major active fault systems and predicting their historical role in the paleogeography of an area.

Domaines: Sciences de la Terre

J. Jackson, J. Gagnepain, G. Houseman, G.C.P. King, P. Papadimitriou, et al.. Seismicity, normal faulting, and the geomorphological development of the Gulf of Corinth (Greece): the Corinth earthquakes of February and March 1981. Earth and Planetary Science Letters, 1982, 57 (2), pp.377 - 397. ⟨10.1016/0012-821X(82)90158-3⟩. ⟨hal-01400419⟩