Slab segmentation controls the interplate slip motion in the SW Hellenic subduction: New insight from the 2008 Mw 6.8 Methoni interplate earthquake

• Published in: Geophysical research letters Vol. 43; no. 18; pp. 9619 - 9626
• Main Authors: Sachpazi, M., Laigle, M., Charalampakis, M., Sakellariou, D., Flueh, E., Sokos, E., Daskalaki, E., Galvé, A., Petrou, P., Hirn, A.
• Format: Journal Article
• Language: English
• Published: 28.09.2016
• Subjects: sea‐bottom morphology; segmentation of the interplate thrust fault; seismic activity and structure; upper plate deformation
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2016GL070447

We present an integrated approach of the seismic structure and activity along the offshore SW Hellenic subduction from combined observations of marine and land seismic stations. Our imaging of the slab top topography from teleseismic receiver function analysis at ocean bottom seismometers supports a trenchward continuation of the along‐dip slab faults beneath the Peloponnesus. We further show that their morphostructural control accounts for the backstepping of the thrust contact of the Mediterranean Ridge accretionary wedge over the upper plate. Local seismic activity offshore SW Peloponnesus constrained by ocean bottom seismometer observations reveals a correlation with specific features of the forearc: the Matapan Troughs. We study the Mw 6.8 14.02.2008 interplate earthquake offshore SW Peloponnesus and show that its nucleation, rupture zone, and aftershocks sequence are confined to one slab panel between two adjacent along‐dip faults and are thus controlled by not only the offshore slab top segmentation but also the upper plate sea‐bottom morphology. Key Points Joint observations of seismic activity and structure Offshore extension of the SW Hellenic slab top segmentation Mw 6.8 Methoni interplate hypocenter and rupture pattern relation with slab segmentation, upper plate deformation, and bathymetric features