← Back to Sessions

Seismicity and Seismotectonics in the Kefalonia Transform Fault Zone (KTFZ), Greece

Description: 

The Kefalonia Transform Fault Zone (KTFZ), which extends for more than 150 km offshore and along the western coastlines of Kefalonia and Lefkada Islands, is one of the largest sources of seismic hazard in the Aegean region. It is composed of five major and numerous secondary fault segments and bends. We have synthesized the characteristics of this seismogenic zone by analyzing earthquake data recorded during the past 20 years (2003–2022). The seismicity is mainly distributed onshore along the coastline, in the depth range from 5 to 15 km, primarily associated with strike–slip faulting. From the seismicity and fault plane solutions analysis we integrated the major physical features of the regional seismotectonic. We suggested a comprehensive seismotectonic model that improves our understanding and must be taken into account in any seismic hazard model. Fault plane solutions confirm that the direction of maximum horizontal stress is dominantly northeast–southwest over almost the entire area. From analyzing groups of earthquakes, we can infer temporal and spatial variations of earthquake source properties, as well as the properties and the evolution of the stress field. Although the major faults are dipping to the east, and southeast, the northern continuation of the Lefkada fault is dipping to the northwest. We are then suggesting that the dextral strike-slip dies out to the north of the Lefkada branch of KTFZ as it is probably transferred to the neighbor fault populations as at this edge it meets continental collision to the north. Between the Lefkada and Kefalonia branches of the KTFZ step-over secondary faults are developed that might be considered as splays beyond the major faults representing a broad damage zone. Such damage zones are interpreted to be due to the stress concentrations at fault tips and linking zones. Our seismotectonic model illustrates that the KTFZ is a long, continuous structure with multiple segments that exhibit complex geometries and kinematics.

Session: Tectonics and Seismicity of Stable Continental Interiors

Type: Oral

Date: 4/19/2023

Presentation Time: 10:45 AM (local time)

Presenting Author: Vasileios Karakostas

Student Presenter: No

Invited Presentation: 

Authors