Relaxation on the Ismetpasa segment of the North Anatolian Fault after the Golcuk M-w=7.4 and Duzce M-w=7.2 shocks

Abstract

The Ismetpasa segment of the North Anatolian Fault (NAF) is a rare place where aseismic fault slip (creep) has been observed. Its creep behaviour has been monitored using different observation methods since the 1950s. The findings obtained from the studies until 1990s showed that the creep rate exponentially decreased before the major shocks in 1999, Golcuk (M-w = 7.4) and Duzce (M-w = 7.2). After these shocks, three GPS periods observation in 2002, 2007 and 2008 were carried out on the geodetic network established around the segment. The evaluations of these observations showed that the creep behaviour relaxed after the major earthquakes. This result demonstrates that the creep behaviour of the Ismetpasa segment might be a warning before future major earthquakes.