Geodetic slip model of the November 26, 2019 Albania earthquake estimated from Sentinel-1 TOPS interferometry

Abstract

This study uses Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) data to investigate the source model of the 26 November 2019 Albania earthquake, the largest earthquake to hit the northwestern region of the country in the last century. The preferred InSAR-based coseismic slip model shows that the slip is distributed in a relatively narrow area and is located at a depth of ~11 km with a maximum amplitude of ~0.89 m. The estimated geodetic moment of this earthquake is 3.70 × 1018 Nm, with a shear modulus of 40 GPa, which is equivalent to Mw 6.31. The preferred slip model shows that this earthquake ruptured an east-dipping fault, namely the Shijak Fault wherein the primary slip mechanism is the dip-slip motion. Two-dimensional (2.5-D) surface displacement derived from three pairs of InSAR data is used to ensure the dip direction of the seismogenic fault responsible for the 2019 Albania earthquake. The result of 2.5-D displacement shows the dominance of the westward and uplift motion with a maximum amplitude of ~0.1 m. It indicates that the source fault dips to the east, confirming the result of inversion analysis.