Application of the Environmental Seismic Intensity scale (ESI 2007) and the European Macroseismic Scale (EMS-98) to the Kalamata (SW Peloponnese, Greece) earthquake (Ms=6.2, September 13, 1986) and correlation with neotectonic structures and active faults

Abstract

On September 13, 1986, a shallow earthquake (Ms=6.2) struck the city of Kalamata and the surrounding areas (SW Peloponnese, Greece) resulting in 20 fatalities, over 300 injuries, extensive structural damage and many earthquake environmental effects (EEE). The main shock was followed by several aftershocks, the strongest of which occurred two days later (Ms=5.4). The EEE induced by the 1986 Kalamata earthquake sequence include ground subsidence, seismic faults, seismic fractures, rockfalls and hydrological anomalies. The maximum ESI 2007 intensity for the main shock has been evaluated as IX<sub>ESI 2007</sub>, strongly related to the active fault zones and the reactivated faults observed in the area as well as to the intense morphology of the activated Dimiova-Perivolakia graben, which is a 2nd order neotectonic structure located in the SE margin of the Kalamata-Kyparissia mega-graben and bounded by active fault zones. The major structural damage of the main shock was selective and limited to villages founded on the activated Dimiova-Perivolakia graben (IX<sub>EMS-98</sub>) and to the Kalamata city (IX<sub>EMS-98</sub>) and its eastern suburbs (IX<sub>EMS-98</sub>) located at the crossing of the prolongation of two major active fault zones of the affected area. On the contrary, damage of this size was not observed in the surrounding neotectonic structures, which were not activated during this earthquake sequence. It is concluded that both intensity scales fit in with the neotectonic regime of the area. The ESI 2007 scale complemented the EMS-98 seismic intensities and provided a completed picture of the strength and the effects of the September 13, 1986, Kalamata earthquake on the natural and the manmade environment. Moreover, it contributed to a better picture of the earthquake scenario and represents a useful and reliable tool for seismic hazard assessment.

Earthquake-Induced Tsunamis in Western Greece (Ionian Sea and Western and Southern Peloponnese): Use of Tsunami Quantities, Impact and ITIS-2012 Intensities for Highlighting Susceptible Areas

“…As regards the western and southern Peloponnese, onshore and offshore studies revealed that it is composed of megahorsts and megagrabens bounded by N-S-and E-W-trending active fault zones and seismogenic faults [84,85,[91][92][93][94][95][96]. Offshore studies conducted in the Kyparissia [96], Messenian [97] and Laconian [98] Gulfs demonstrated that active faults observed onshore in the study area continue in several cases offshore.…”