Revealing 3D Subsurface Structure of Paliki Peninsula, Kefalonia, Greece
Description:
Paliki Peninsula, the western end of Kefalonia Island, has been repeatedly hit by moderate to large earthquakes and is located in one of the most active seismotectonic regions of the Mediterranean Sea, to the east of the major Kefalonia-Lefkada transform fault. In 1953, an Mw 7.0 earthquake, preceded by two Mw 5.9 and Mw 6.6 foreshocks, produced extensive damage in Kefalonia. More recently, in 2014, a sequence with two main shocks (~ Mw 6.0) within eight days caused considerable damage and ground failure in the Paliki Peninsula. To develop a new 3D subsurface model for understanding site effects and to compute a more detailed velocity model for accurately locating earthquakes, a joint geophysical field campaign was organized in September 2024. During this campaign, we installed eight cross-profiles and one array through the Paliki Peninsula, using 24 SmartSolo IGU-16HR 3C nodes, three SmartSolo IGU-BD3C-5LC broadband devices and two Tromino instruments. Ambient noise measurements were carried out at 220 locations, resulting in 3225 hours of recorded ambient noise data, including recordings of tens of small earthquakes. Array- and cross-correlation techniques, and Horizontal to Vertical Spectral Ratios (HVSR) were applied to model the shallow sedimentary cover and variation in bedrock depth, for better understanding the impact of earthquakes on this area. Preliminary results show increasing thickness of Miocene marls deposits from west to east, overlaying a bedrock of Eocene limestones deeping towards the eastern shoreline of the peninsula, with a steeper attitude in the north. To our knowledge, this is the first time that such large-scale fieldwork has been performed on the Ionian Islands and the recorded data will stimulate new research studies, contributing significantly to more precise earthquake locations, and more accurate local hazard assessments and risks evaluations.
Session: Innovative Applications of Seismic Nodal Technology for Hazard Mitigation and Earth System Monitoring [Poster]
Type: Poster
Date: 4/15/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Mariano
Student Presenter: No
Invited Presentation:
Poster Number: 11
Authors
Mariano Garcia-Fernandez Presenting Author Corresponding Author mariano.garcia@csic.es Spanish National Research Council - Institut de Ciencies del Mar |
Koen Van Noten koen.vannoten@seismology.be Royal Observatory of Belgium |
María José Jiménez mj.jimenez@csic.es Spanish National Research Council - Institut de Ciencies del Mar |
Nikolaos Sakellariou nikolaos.sakellariou@mncn.csic.es Spanish National Research Council - Institut de Ciencies del Mar |
Raphael De Plaen raphael.deplaen@oma.be Royal Observatory of Belgium |
Vasiliki Kouskouna vicki.kouskouna@gmail.com National and Kapodistrian University of Athens |
Thomas Lecocq Thomas.lecocq@seismology.be Royal Observatory of Belgium |
Sara Rodriguez-Diaz sara.rodriguez@mncn.csic.es Spanish National Research Council - Institut de Ciencies del Mar |
Nikolaos Galanos nikolasgal@yahoo.gr National and Kapodistrian University of Athens |
Revealing 3D Subsurface Structure of Paliki Peninsula, Kefalonia, Greece
Category
Innovative Applications of Seismic Nodal Technology for Hazard Mitigation and Earth System Monitoring