Observation of the spread of slow deformation in Greece following the breakup of the slab

Virginie Durand (1) , Michel Bouchon (2) , Michael Floyd (3) , Nikos Theodulidis (4) , David Marsan (2) , Hayrullah Karabulut (5) , Jean Schmittbuhl (6, 7)

1 IPGP - Institut de Physique du Globe de Paris
2 Mécanique des failles
3 EAPS - Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge]
4 ITSAK - Institute of Engineering Seismology and Earthquake Engineerits
5 KOERI - Kandilli Observatory and Earthquake Research Institute
6 IPGS - Institut de physique du globe de Strasbourg
7 EOST - Ecole et Observatoire des Sciences de la Terre

Over the past two decades, geophysical observations have shown that earthquakes can trigger other earthquakes, raising the possibility that earthquake interaction plays an important role in the earth's deformation. We analyze here a "storm" of earthquakes in Greece and show that their interaction provides remarkable insight into the mechanics of one of the fastest deforming continental region in the world. A rupture of the African slab initiates a cascade of large earthquakes and a long episode of slow slip marking the downward plunge of the slab, the concomitant rollback of the subduction, and the subsequent detachment of southern Greece from the Eurasian plate. Intense crustal deformation, indicative of the resulting plate stretching, follows. This slow deformation which spreads in a few months over more than 500 km lasts~3 years and triggers earthquakes. The observations also show that the retreat of the African subduction is the motor of the Aegean deformation.

Domaines: Géophysique [physics.geo-ph]

Virginie Durand, Michel Bouchon, Michael Floyd, Nikos Theodulidis, David Marsan, et al.. Observation of the spread of slow deformation in Greece following the breakup of the slab. Geophysical Research Letters, 2014, 41 (20), pp.7129-7134. ⟨10.1002/2014GL061408⟩. ⟨hal-02323406⟩