On the recent large EQ of Karpathos, Greece (April 1st, 2011, Ms = 6.7R) and its similarities to the large EQ of the January 1st, 2006 (Ms = 6.9R) at East of Kythira, Greece

TL;DR

This study analyzes two large Greek earthquakes in 2006 and 2011, examining their geophysical features, precursors, and regional tectonic mechanisms, and finds consistent electric field signals preceding both events.

Contribution

It identifies electric field precursors and regional tectonic similarities between two major Greek earthquakes, validating specific geophysical models.

Findings

Electric precursors appeared 1-2 days before both earthquakes.

Similar electric field patterns observed at different monitoring sites.

Both earthquakes linked to the same regional tectonic mechanism.

Abstract

The recent large EQ that occurred in Greece (April 1st, 2011, Ms = 6.7R) is investigated as far as it concerns regional geophysical features of the Greek territory. In particular, the EQ location is compared to the deep lithospheric fracture zones and faults, derived from the analysis of the corresponding earth's gravity field; to the current seismic potential map determined from the study of the past seismicity, while its time of occurrence is compared to the peaks of the M1 and diurnal tidal waves. The detailed investigation of the earth's electric field that was recorded by the ATH monitoring site, located in Athens, revealed the presence of short train like pulses type electric seismic precursory signals which were generated short (1 - 2 days) before the EQ occurrence time. Moreover, the analysis (for T = 1 day) of the earth's oscillating electric field, that was simultaneously recorded at PYR and ATH monitoring sites, revealed that the "strange attractor like" seismic electric precursor preceded for 1 - 2 days the EQ occurrence time. A similar behavior was observed from the large EQ of the East Kythira (Ms = 6.9R, January, 8th, 2006). It is concluded that the same regional tectonic mechanism controlled and generated both the analyzed EQs while the adopted geophysical earth models have been validated.