Statistical reinterpretation of the long term creep behaviour of the Ismetpasa segment of North Anatolian Fault, Turkey

Abstract

The Ismetpasa segment of the North Anatolian Fault (NAF) is where an aseismic creeping behaviour is observed. As a result, earth scientists are focused on the Ismetpasa segment to understand and explain the nature of creep behaviour. The studies conducted on the segment are based on many different techniques such as simple measuring tape observations, InSAR and GNSS observations, depending on the technological capabilities of the year in which the study is conducted. In this study, GPS (2012–2019) and PS-InSAR (2015–2019) techniques were used to compute and analyse the creep rate in the last decade and compare previous findings. The computed creep rates with GPS and PS-InSAR are about 0.88 ± 0.1 cm/yr and 0.68 ± 0.2 cm/yr, respectively. The creep rates given in previous studies vary between 0.61 ± 0.02 cm/yr and 2.0 ± 0.6 cm/yr. Based on these results, different scenarios in the literature were claimed about the creep behaviour at the Ismetpasa segment. However, none of the studies considered statistical tests to investigate the significance level of the differences between the given results. All the results shared for the Ismetpasa segment are evaluated by statistical significance test for the first time, and the results obtained are discussed. Results indicate that the variety between these studies is insignificant, and the creep rate does not change significantly in long term periods.