Geodetic aspects of the 19 May 2011 Simav earthquake in Turkey

Abstract

On 19 May 2011, an earthquake of magnitude Mw:5.9 occurred just 9.1 km below the surface of the earth on the Simav fault in Turkey. The region is located north-west of the Gediz graben, one of the major tectonic structures in the extensional regime of western Anatolia. In this study, from 2009 to 2011, the data from nine Continuously Operating Reference Stations (CORS-TR) in the region and one permanent Global Navigation Satellite System station working locally were assessed and analysed using GAMIT/GLOBK software. The behaviour of these stations before and after the earthquake was analysed using calculated time series. At the same time, the strain and rotation rates of current deformation in the Simav region were computed using the 2008–2011 data from the CORS-TR network. The directions obtained from the focal mechanism solutions and strain analysis of the Simav earthquake were observed as being in harmony. Nonetheless, Simav earthquake caused a displacement of 1–2 mm (approximately) in nearby locations. The Simav earthquake shows that the extensional regime in western Anatolia has recently been active in the region and is a good example of the evolution of the graben system.