The Marmara Sea region: Seismic behaviour in time and the likelihood of another large earthquake near Istanbul (Turkey)

Abstract

The North Anatolian Fault (NAF) extends for about 1500 km from Karliova to the east, to the Egean Sea in the west. The Marmara region, located near the western end of the NAF, is a tectonically active zone characterized by the transition between a strike slip stress regime and an extensional one in the Aegean Sea. Microseismic studies performed around the Marmara Sea in 1995 [Tectonophysics 316, 2000, 1], and just before the 1999 Izmit Earthquake (Bull. Seism. Soc. Am. 92, 2002a, 361; J. Seismol. 6, 2002b, 287) permitted the analysis of the evolution of seismicity connected to this destructive earthquake and its sequels. Several observations indicate that the aftershock distribution fits well the EW orientation of the NAF, but the ruptures are not simple and linear as a first glance would suggest. Instead they are segmented in at least five pieces as shown by the slip variation and aftershock clusters, showing complexity at different scales (Bull. Seism. Soc. Am. 92, 2002a, 361). There is still a gap, across the northern border of the Marmara Sea that has not ruptured, and this is the only sector that did not break on the NAF since the 1939 great Erzincan earthquake. Will it rupture as a whole with a large magnitude earthquake, or by segments with smaller magnitude events? The Hurst analysis of the overall behaviour of the seismicity in the Marmara region since historical times shows that if a large earthquake occurs in the near future, it might break the complete gap. The Hurst character of the time variation of seismicity is persistent with H = 0.82. The aftershocks of the 1999 Izmit earthquake can be analyzed by using the Hurst method, showing an exceptionally high persistent memory.

A relationship between Hurst exponents of slip and waiting time data of earthquakes

“…Refs. [15,10,3,6,18,2]. Each research group constructed their own time series for the R/S analysis from the earthquake catalogue.…”

“…Telesca et al [18], for example, had analyzed the temporal fluctuations of the Hurst exponent H for the waiting time of the earthquakes occurred in southern Italy and found the values of H range from 0.5 to 0.92 with a mean of 0.74. Cisternas et al [2] had constructed the cumulative seismic moment as a function of time for conducting the R/S analysis of the seismicity in the Marmara Sea Region, Turkey, and concluded that the aftershocks of the 1999 Izmit earthquake show an exceptionally high persistent memory with the H of 0.95.…”

“…However, one significant difference between the real and synthetic catalogue is the coverage of H for the real catalogue, which extends from ∼0.4 to ∼1, is larger than the synthetic one. It strongly suggests that the so-called "memory" effect may exist in the real earthquake data [3,2]. , also from a synthetic catalogue based on the time-predictable earthquake recurrence model (circles).…”

Seismic behaviour of the North Anatolian Fault beneath the Sea of Marmara (NW Turkey): implications for earthquake recurrence times and future seismic hazard

“…These studies have comprised reassessment of historical seismicity (Ambraseys and Jackson 2000;Ambraseys 2001aAmbraseys , b, 2002a, monitoring of microseismicity (Sato et al 2004), high-resolution bathymetry and multi-channel seismic reflection studies (Okay et al 2000;Le Pichon et al 2001;Armijo et al 2002Armijo et al , 2005Parke et al 2002;Gökaşan et al 2003;Demirbag et al 2003;McHugh et al 2006;Kanbur et al 2007), earthquake focal mechanism-derived stress orientations (Polat et al 2002;Pınar et al 2003), field geology (Altınok et al 2003;Seeber et al 2004;Okay et al 2004;Altunel et al 2004), paleoseismology (Rockwell et al 2001;Klinger et al 2003;McHugh et al 2006), Coulomb static stress change modelling (Hubert-Ferrari et al 2000;Parsons et al 2000;Utkucu et al 2003;Parsons 2004;Lorenzo-Martin et al 2006;Pondard et al 2007), space geodesy (Meade et al 2002;Flerit et al 2003) and earthquake probability (Parsons et al 2000;Parsons 2004;Cisternas et al 2004) studies. The basin of the Sea of Marmara was considered as a rift with a strike parallel to the proposed western Turkey rift system in the earlier phase of the construction of the plate kinematics of the eastern Mediterranean region (McKenzie 1972).…”

An Assessment of the Seismicity of the Bursa Region from a Temporary Seismic Network

“…The thickness of the units varies from 50 to 200 m near the Yenisehir basin (TOPAL et al, 2003). The GIFZ zone corresponds to the NAFSS and has the potential to generate a strong earthquake (GULKAN et al, 1993;CISTERNAS et al, 2004). It extends from the east of Iznik Lake to the northern slopes of the UM along the Yenisehir plain (OZTURK et al, 2009).…”