Impact of the Crustal Velocity Model on Earthquake Location and Moment Tensor Solution: Case Study on the 2025 Aegean Sea Earthquakes

Abstract

The densely populated areas in the Eastern Mediterranean are highly vulnerable to a variety of geohazards, including earthquakes, tsunamis, volcanoes and landslides. The Cyclades archipelago region near Santorini in the Aegean Sea lies within a tectonically active belt capable of generating volcanic activity, major destructive earthquakes and subsequent landslides and/or tsunamis. Understanding the properties of plate boundaries, slabs, active faults and the stress field is crucial for identifying the geodynamic factors driving plate deformation and associated geohazards. A dense seismic network is crucial for precisely locating earthquakes and understanding the active tectonics of the area. In recent years, dense seismic networks such as AdriaArray, have been conducted to provide high quality data for imaging crustal and upper mantle structure, as well as analysing seismic activity in the Mediterranean region. This study focuses on the computation of a 1D velocity model in order to improve the earthquake parameters in the region. Taking advantage of recent deployments, dense station coverage, and a comprehensive earthquake catalogue from recent seismic activity in the Cyclades archipelago, Aegean Sea, a new 1D crustal velocity model was developed and compared with existing models in the region. The presented results emphasize the influence of the crustal velocity model on earthquake parameters and moment tensor solutions, with strong potential to enhance forthcoming investigations into source mechanisms, fault kinematics, and seismic velocity structures in the Aegean Sea.