Co-seismic and post-seismic deformation, field observations and fault model of the 30 October 2020 M w = 7.0 Samos earthquake, Aegean Sea

Acta Geophysica

article

Ganas, Athanassios¹  Elias, Panagiotis²  Briole, Pierre³  Valkaniotis, Sotiris⁴  Escartin, Javier³  Tsironi, Varvara¹  Karasante, Ilektra¹  Kosma, Chrysanthi¹ 

[1] Institute of Geodynamics, National Observatory of Athens;Institute of Astronomy, National Observatory of Athens;Laboratoire de Géologie - UMR CNRS 8538, PSL Research University;Department of Civil Engineering, Democritus University of Thrace;Department of Geology, University of Patras

关键词: Earthquake;    InSAR;    GNSS;    Liquefaction;    Uplift;    Samos;    Aegean;   

DOI  :  10.1007/s11600-021-00599-1

学科分类：地球科学(综合)

来源: Polska Akademia Nauk * Instytut Geofizyki

【 摘 要 】

On 30 October 2020, a large Mw = 7.0 earthquake occurred north of the island of Samos, Greece. Here we present the characteristics of the seismic fault (location, geometry, geodetic moment) as inferred from the processing of geodetic data (InSAR and GNSS). We use the InSAR displacement data from Sentinel-1 interferograms (ascending orbit 29 and descending 36) and the GNSS offsets from fourteen (14) stations in Greece and Turkey to invert for the fault parameters. Our inversion modelling indicates the activation of a normal fault offshore Samos with a length of 40 km, width of 15 km, average slip of 1.7 m, a moderate dip-angle (37°) and with a dip-direction towards North. The inferred fault is located immediately north of, and adjacent to Samos with the top of the slip ~ 0.6 km below surface, and ~ 1 km offshore at its closest to the island. Near the fault, the earthquake caused the permanent uplift of the island up to 10 cm with the exception of a coastal strip along part of the northern shore that subsided 2–6 cm. The co-seismic horizontal motion of GNSS station SAMO was 35.6 cm towards south and 3 cm towards west. A post-seismic signal (22–33% of the co-seismic on the vertical component) was observed at GNSS stations SAMO and SAMU, with a time constant of 30 days. The effects of the earthquake included liquefaction, rock falls, rock slides, road cracks and deep-seated landslides, all due to the strong ground motion and associated down-slope mobilization of soil cover and loose sediments.

【 授权许可】

Unknown