C2S-RLN | Collision to Subduction: from the Dinarides-Hellenides Junction to the ocean-continent transition at the Kefalonia Transform Fault System - a rolling Large-N experiment

The eastern margin of the Adriatic plate is a region of high seismic hazard. Observations of earthquakes and surface faulting reveal a complex array of focal mechanisms, fault orientations and slip vectors over a broad area of distributed deformation. The sources of stress that drive surface deformation are also poorly constrained: subduction/collision dynamics, in particular the change from continental collision to oceanic subduction along the Kefalonia Transform Fault Zone (KTFZ), likely exert a profound influence, but contributions from topographic contrasts (gravitational potential energy) are also significant. We propose the deployment of a high density mobile seismic network consisting of ~400 geophones and 50 broadband stations, which will allow for imaging of crustal and upper mantle structures, velocities and seismicity at high resolution. Careful separation of faulting styles and a comparison between surface expression, present-day seismic activity, and seismic velocity structure will aid in understanding the kinematic evolution of the region as well as provide insights into the controlling forces, thus addressing both themes 1 and 2 of the SPP DEFORM. The information on faulting geometries and activity together with the high resolution model of elastic properties will provide constraints on dynamic models of the region and are a prerequisite of physical dynamic rupture models for large earthquake scenarios.

The GFZ is participating in the operation of the Large-N array, making use of a loan of GIPP stations (geophones and broadband stations). Analysis is concerned with generating a high resolution machine-learning based seismicity catalogue, including focal mechanisms, as well as interpreting results in terms of the seismotectonics of the study region.

The project is carried out as part of the SPP 2497:  Plate Deformation and Geohazards: The Eastern Margin of the Adriatic Plate (DEFORM)