To monitor the microseismic activity in the North Anatolian Fault Zone offshore of Istanbul below the Çinarcik Basin (ÇB) a permanent seismic array (see PDF) was installed on the Prince Islands in 2006, at a very close proximity to the main fault.

PIRES initially consisted of two 5-station sub-arrays installed on the two outermost islands (Yassiada and Sivriada) of the Princes Islands group offshore Istanbul (see insets below). PIRES has later been enlarged towards the other Princes Islands in order to improve the azimuthal control of the focal area now consisting of 16 stations on a total of seven islands. We additionally integrate data from local permanent stations of the Turkish network (KOERI) and the ARNET seismic network. Combined data allowed obtaining a well-resolved scale for the hypocentral map to better understand the existing seismically active structures and their role in local tectonic settings. This allowed resolving the major fault branches beneath the ÇB providing insights into separation of seismically active/inactive segments along the western seismic gap and down-dip geometry of the seismically active faults.

Spatiotemporal analysis of the seismicity based on well-constrained hypocenters is performed to understand the interaction between the sub-segments of the NAFZ along the ÇB.