Interpretation of Low Seismicity in the Eastern Anatolian Collisional Zone Using Geophysical (Seismicity and Aeromagnetic) and Geological Data

Abstract

The eastern Anatolia is a continental collisional zone between the Arabia-Eurasia plates and is currently being accompanied by the westward escape of the Anatolian crustal block to the west-southwest along two major strike-slip fault zones, the NATF and the EATF. Although these major fault zones have experienced historical earthquakes with moderate to high magnitude, notably there is a low seismicity zone on the active EATF between the Bitlis and Pötürge massifs. The low seismicity zone is characterized by thinner crustal structure relative to its environs, the shallow Curie Point Depth (SCPD, ca 12-14 km in between 39-40°E and 38.5-39°N in the easternmost part of the Anatolian plate) and moderate to high b values (more than 0.7). We consider that the shallow CPD and moderate to high b values in the low seismicity zone characterized by thinner crustal area are closely related with the higher thermal structure of the crust, which most probably resulted from crust-hot asthenospheric mantle interactions.

Imaging of subsurface lineaments in the southwestern part of the Thrace Basin from gravity data

“…The frequently-used enhancement techniques are contrast healing, border fixing, and filtering (Zhang et al, 2005). Examples of border fixing related studies are Aydogan (2007, 2008, 2011), Blakely and Simpson (1986, Dolmaz et al (2008), Dolmaz (2008), McGrath (1991), Mallat and Zhong (1992), Moreau et al (1997), Oruç and Keskinsezer (2008), Selim (2011), Trompat et al (2003). The most classical methods in geophysics are the approaches based on derivative calculations.…”