The 8 January 2013 (Mw=5.7) and 24 May 2014 (Mw 6.7) Northern Aegean Earthquakes and Their Aftershocks Distribution

Abstract:

The Northern Aegean Sea and its surrounding offshore North Aegean islands area is one of the most seismically active and recent deforming region between the Eurasia and Anatolia continents. On 8^th January 2013 at 14:16 UTC (16:16 local time) a moderate earthquake (Mw= 5,7) occurred between the south of Gokceada and southwest of Bozcaada Islands in the North Aegean Sea. The earthquake was felt at a wide area. Especially felt in the NE Greece and NW Turkey surrounding areas, such as felt at Canakkale, Marmara Region and Northern Aegean coast as well as to Athens. The epicenter coordinates were calculated as 39.646N-25.483E and the focal depth was 8.4 km. according to the Kandilli Observatory & Earthquake Research Institute (KOERI). After main shock, in the first 40 hours 160 aftershocks were determined with magnitudes Ml=1.6 -5.0. The area is defined as the continuation of the branch of North Anatolian Fault (NAF) inside the Aegean Sea. Fault plane solution determined by this study shows that the earthquake occurred because of the rupture of an NE-SW oriented strike slip fault segment. The aftershocks distribution also supported the rupture of the NE-SW oriented fault.

Approximately 17 months after, second big earthquake occurred in the same area. On 24th May 2014, at 09:25 UTC (12:25 local time), a powerful Ml=6.7 (Mw=6.8) earthquake hit Greece and Turkey, in Aegean Sea, 87 km W of Canakkale, and and several tens of people were injured in this hit in Greece and Turkey. This earthquake has been largely felt in Greece, Turkey, Bulgaria, Romania, and the Balkans. After this earthquake, 576 aftershocks were determined with magnitude range M=0.9- 4.8 in first 96 hours. The main-shock occurred on a fault with a NE-SW strike, where the largest portion of the energy was released towards these directions. Therefore the earthquake was felt strongly in Canakkale-Istanbul and Marmara region. In this study we calculated focal mechanism solutions with first motion direction of P wave and moment tensor solutions for main-shock and important aftershocks (M>4.0). Moment tensor solutions show generally strike-slip faulting. The fault which caused earthquake, is thought to be a branch of North Anatolian Fault Zone in the North Aegean Sea.