The Cephalonia, Ionian Sea (Greece), sequence of strong earthquakes of January-February 2014: a first report

Abstract

On 26.1.2014 and 3.2.2014 two strong earthquakes of M w 6.0 and M w 5.9 ruptured the western Cephalonia Isl., Ionian Sea (Greece), at the SSW-wards continuation of the Lefkada segment of the Cephalonia Transform Fault Zone (CTFZ), causing considerable damage and a variety of ground failures. High-precision relocation of the aftershocks implies that the seismogenic layer was of 35 km in length (L) striking NNE-SSW, of 10 km maximum in width and 15 km in thickness. Two aftershock 2014 earthquakes ruptured on land western Cephalonia we suggested to revise the CTFZ geometry in the sense that the Lefkada CTFZ segment does not terminates offshore NW Cephalonia but extends towards SSW in western Cephalonia.

Techniques of Rockfall Inventory in Earthquake Prone Rock Slopes

“…Today's rockfall hazard issues and estimation of the risk of rock fall are considered essential. Recent earthquakes in Alkyonides islands (Marinos et al, 1986), Parnitha Mt (Pavlides et al, 2002), Movri Mt (Koukouvelas et al, 2010, Lefkada (Papathanassiou et al, 2013) and Cephalonia island (Papadopoulos et al, 2014) showed that Greek type earthquakes are usually accompanied by small to large scale slope instabilities, including commonly rockfalls. Taken together the recent impacts of ground shaking in Greece and the preliminary results from two areas of high seismic risk we identify that the method used can give reliable results.…”

Earthquake Triggering Effect Scenarios During the 2014 Sequence in Cephalonia and 2015 Earthquake in Lefkada Broader Areas, Ionian Sea, Greece

“…The relocated hypocentral depth is estimated to 16.5 km , while its aftershock distribution occurred above the focal depth having a rather steep, E-dipping trend . The proposed moment tensor by Papadopoulos et al (2014) shows an almost pure strike-slip, ESE-dipping fault plane (strike/dip/rake = 023°/68°/175°; Figure 2). The second strongest event (Mw5.3, NOA) occurred almost 5 hours after the first one at a relocated depth of 12.5 km.…”

“…Unfortunately, the aftershock sequence of this event could not be isolated because it overlapped with the mainshock's aftershock sequence. The moment tensor proposed by Papadopoulos et al (2014) reveals a pure reverse, ENE-dipping fault (strike/dip/rake = 352°/40°/89°; Figure 2). …”

“…The horizontal distribution of relocated aftershocks Papadopoulos et al, 2014) covers the entire peninsula of Paliki continuing offshore Myrtos Bay to the north. Three major shocks having magnitudes over 5 occurred in that seismic sequence ( Figure 2).…”

Recent seismic activity at Cephalonia (Greece): a study through candidate electromagnetic precursors in terms of non-linear dynamics

“…The second significant EQ, M w = 5.9, hereafter also referred to as "EQ2", occurred on the same island on 3 February 2014 (03:08:45 UT), with epicentre at (38.25 • N, 20.40 • E) and a depth of ∼ 10 km. Various studies of the two earthquakes have already been published, indicating their seismotectonic importance (Karastathis et al, 2014;Valkaniotis et al, 2014;Papadopoulos et al, 2014;Ganas et al, 2015;Sakkas and Lagios, 2015;Merryman Boncori et al, 2015) as they were located on two different active faults that belong to the same seismic source zone.…”