Determination of Strain Rates and Velocity Field in Geodetic Control Networks Along Western North Anatolian Fault by GPS

Project Manager: Prof. Dr. Haluk Özener
Project Code: 7506
Project Start Date: 2013
Project Budget: 36000 TL
Since 1970s, geodetic studies have been carried out for detecting crustal movements along North Anatolian Fault Zone in Turkey. Geodesy Department of Kandilli Observatory and Earthquake Research Institute at Boğaziçi University has conducted20 scientific projects with support of BU-Scientific Research Projects Fund. In this context, three geodetic control networks wereinstalled in the regions having significant seismic hazard. One of them is located in Iznik, an area of low seismicty; the other one is Sapanca which is the most seismically active region; and the third network is located in Akyazı where the fault splays in two branches. These networks have been measured by conventional geodetic techniques, then GPS technique has been applied and they have been connected to regional geodynamic GPS Networks. These networks have importance in contributing to theassesment of seismic hazard in the region inferred from episodic GPS observations.
In order to monitor tectonic deformation in other regions with high earthquake hazard such as East Anatolia (16-point network, 2003-2006) and Aegean Region (16-point network, 2009-2012), the Department has installed geodetic networks and organized GPS campaigns. Furthermore, two additional geodetic networks has been surveying by GPS technique for several years. These networks are Ismetpasa (estalished by ITU in 1981) and Iznik-HGK (established by ITU and GCM in 1941) networks.
GPS technique plays a very important role in understanding of earthquake mechanism in each phase of seismic cycle, i.e., the pre-, co- and postseismic stage. Co-seismic movements depend on the amount of slip and the depth of the earthquake. Near-field GPS observations can be used to obtain strain accumulating across locked faults and can therefore help us to determine the seismic potential of the region of interest. It is also necessary to link the short-term geodetic observations to the medium and long-term trends.In the scope of the proposed project, it is aimed to ensure the continuity of the measurements, examine the change in the magnitude of the velocity vectors, and identify the current velocity field and strain accumulation through these geodetic networks