A moderate 5.8Ms magnitude earthquake hit the central Aegean Skyros island worst hit, but no injuries have been reported

---

On July 26, 2001 a moderate earthquake of 5.3M_L (5.8M_S) magnitude hit the central Aegean at 03:21 a.m. local time. The event located by the Institute of Geodynamics at the sea area North of Skyros island and in a 130km distance NNE of Athens. A sequence of aftershocks has followed with magnitudes reaching 5.2M_S.

It is important to note that the event was felt in a wide region about 200km radius around the epicentral area sending many residents into the streets. This possibly is due to the focal mechanism in combination with the thick crustal structure of the broader Sporades Basin.

Approximately 90 houses, mostly old traditional dwellings in the capital of Skyros were damaged. Amongst them, the almost 1000 years old monastery of St George the Arab which is situated inside the castle was badly damaged.

A landslide was formed from big boulders crashing parked cars beneath the steep hill of the castle side.

The biggest effect to the Skyros capital population was the cut off  the spring which supplies with water the area.

This event indicates that although the North Aegean Trough is characterised as a region of high seismicity, the seismic hazard is low.

 A first analysis of the waveforms recorded at the only digital broadband permanent seismic network operating in Greece by the National Observatory of Athens, Institute of Geodynamics is presented here (see Figure).

(1) A map showing the digital 3 component broadband station seismic network operating permanently in Greece.

(2) Fault plane solution (see Figures 1, 2, 3) computed by seismologists of  the Institute of Geodynamics in collaboration with Charles University, Faculty of Mathematics and Physics (Prague, Czech Republic) using the ASPO method (Zahradnik et al. 2001).

(3) Aftershock sequence for magnitude threshold 3.5Ms recorded within the first 48hrs.

Compiled by George N. Stavrakakis, Nicos S. Melis and Vassilis K. Karastathis