Teleseismic Source Process of The October 30, 2020 Kuşadası Gulf –İzmir (Turkey) Earthquake (Mw=6.8)

Abstract

The October 30, 2020 Kuşadası Gulf-İzmir earthquake took place along a fault bounding Kuşadası Gulf in the South causing significant damage and loss of life, especially in İzmir city. The earthquake damage due to the strong ground motion is augmented by a tsunami that caused a water inundation. In the present study the source properties of the earthquake are investigated by inverting teleseismic P waveforms. The complex waveforms are fit with two subevents in the point-source inversion that requires dominant normal faulting along a roughly E-W trending normal fault dipping north. The finite-source inversion shows that the earthquake is due to failure of a two asperities with slip as high as 2.4 m and the rupture covers a fault area of 30 km x 20 km with unilateral propagation toward west. The finite-source model defines two asperities that are located at hypocentral area and shallow depths near the west top corner of the fault. The earthquake rupture lasts for 17 s and released a seismic moment of 2.21 x 1019 Nt.m (MW=6.83). Presence of a shallow asperity indicates that rupture reaches to the sea bottom which provides a reasonable explanation for the damaging tsunami.

Keywords

• The 2020 Kuşadası Gulf-İzmir earthquake
• teleseismic point-source inversion
• teleseismic finite-source inversion
• Extensional tectonics

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