Regional and Temporal Analyses of the Current Earthquake Activity in and around the North Anatolian Fault Zone

In this study, the regional and temporal variations of seismicity in and around the North Anatolian Fault Zone, one of the most seismically active strike slip fault systems in the World, are analyzed by using the seismotectonic b-value, fractal dimension Dcvalue, precursory seismic quiescence Z-value and correlations with each other. In order to produce an up-to-date and reliable statistical relation, several regression methods are tested. In and around the NAFZ, the relation of Dc=2.46-0.58*b having a very strong negative correlation coefficient, r=-0.98, is calculated as a more reliable relation. Significant fluctuations are observed in the temporal changes of b and Dc-values and the decreasing in b-value and thus the increasing trend in Dc-value between the years of 2012 and 2013 may be important in terms of the next earthquake potential in and around the NAFZ. The b-values lower than 1.0 and also the Dc-values larger than 1.85 are observed in the regions covering the vicinity of Düzce fault and the Black Sea coast, the vicinity of Pülümür fault and Erzincan, between Pülümür and Karlıova, Sancak-Uzunpınar and Göynük fault zones. At the beginning of 2016, seismic quiescence anomalies are observed in and around Enez, the north of Etili fault, Çanakkale and Edremit, Tekirdağ-Silivri and Marmara Sea, the part of Black Sea and the vicinity of Yalova-İzmit, the northern part of Manyas fault, İznik-Gebze, Düzce fault and the Black Sea coast, İsmetpaşa segment and Laçin-Merzifon fault zone. The regions having both the smallest b-value and the largest Dc-value with the high Z-value are the vicinity of Düzce fault and the Black Sea coast. As an important result, the combination of these seismotectonic parameters may supply some important evidences in order to reveal the next earthquake potential in and around the NAFZ and, these anomaly areas may be interpreted as the possible locations of the next earthquakes.