Determination of Surface Creep Rates by GNSS Measurements Along the Ismetpasa Section


Özdemir A. , Doğan U. , Çakır Z., Ergintav S., Jara J., Jolivet R.

ATAG23, İstanbul, Türkiye, 15 - 18 Ekim 2019, ss.1

  • Basıldığı Şehir: İstanbul
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.1

Özet

Although 50 years ago it was determined that the Ismetpasa segment of the North Anatolian Fault constantly creeping without producing earthquakes, to date, no detailed and reliable information about the temporal and spatial nature of this movement is available. Since the discovery of the deformation caused by the fault at the intersection of the garden wall of the Ismetpasa road maintenance facility in 1969 by Ambraseys (1970), a 6-point geodesic network established only in a small area could be traced by terrestiral surveying and GNSS measurement methods (Aytun, 1982; Altay and Sav, 1991; Deniz et al., 1993; Kutoğlu et al., 2006; Kutoğlu et al., 2008; Özener et al., 2013). In addition, Karabacak et al. (2010) conducted terrestrial Lidar measurements between 2007 and 2009 and Bilham et al. (2016) monitoring creep movement with the creepmeter they established. InSAR studies (Cakir et al., 2005; Kaneko et al., 2013; Cetin et al., 2014) show that the creeping segment is approximately 100 km long and the creep velocity varies spatially, reaching its highest values approximately 15-240 km east of Ismetpasa. Bilham et al. (2016), as shown by the compilation of old data, the creep movement observed in creepmeters does not show continuity, stops from time to time and/or accelerates. Therefore, there are question marks about how much and how fast the slip continues along the direction of the fault and deep. In addition, despite all these studies, the characteristics of the change in the velocity of creep movement and the cause of the beginning (probably 1944 earthquake) are not known. Although it has been reported that a significant part of the cause of sudden changes in creep movement is reported to be related to meteorology, the causes and depth dimension of all transient creep accelerations are not understood from the available data sets. InSAR-PsInSAR (Permenant Scatterers InSAR) and GNSS measurement methods are the most effective methods to find answers to these questions. Naturally, by examining the presence of seismic mobility, it will be possible to determine the characteristics behavior of creep observed on the surface and at the depth.


In order to find answers to all these questions we established ISMENET (Ismetpasa Network). In this presentation, we will give informations about ISMENET stations, velocity field of the area and current creep rates along the Ismetpasa section.


Keywords: NAFZ, Ismetpasa, Creep, ISMENET, GNSS