ACTIVE TECTONIC AND PALEOSEISMOLOGIC CHARACTERISTICS OF THE YENİCE-GÖNEN FAULT, NW TURKEY, IN LIGHT OF THE 18 MARCH 1953 YENİCE-GÖNEN EARTHQUAKE (Ms=7.2)

Abstract

The Yenice-Gönen Fault (YGF) is located in the central part of the Biga Peninsula between Gönen and Yenice and is a right-lateral strike-slip active fault with general trending N65°E. On 18 March 1953 there was an earthquake on the YGF that died 263 people (Ms=7.2) and a 70 km surface rupture developed during this earthquake. In this study measurements of slip distribution were performed on the surface rupture of the Yenice-Gönen Earthquake (YGE) and the annual slip rate on the YGF was calculated. Right-lateral displacements of between 1.70±0.1 and 3.20±0.2 metres were measured on the surface rupture of the YGE. The maximum displacements were in an area close to the central part of the YGF (between Çakır and Karaköy village) and these values decreased relatively in NE and SW directions, documenting that was the bilaterally surface rupture propogation during the YGE. In the last 300.000 years, a total offset of 800±50 metres was measured on Gönen River and annual slip rate of 2.65±0.15 mm was calculated along the YGF. Current GPS studies show right-lateral strike-slip faults in the South Marmara region have slip rates of 6-8 mm/year. This slip rate is assessed as being partitioned between the YGF, Sarıköy Fault and Çan-Biga Fault zones which represent extensions of the North Anatolian Fault system within the South Marmara region. Paleoseismology studies determined that in the last 6200 years 6 earthquakes resulting in surface ruptures have occurred on the YGF, including the 1953 earthquake. According to the 14 C and OSL dating results, the variable and irregular earthquake recurrence interval of YGF is ranging from 505 to 1793 years. In this study average earthquake recurrence interval of YGF was determined as 1180 years.

GPS derived finite source mechanism of the 30 October 2020 Samos earthquake, Mw = 6.9, in the Aegean extensional region

“…Mozafari et al, (2019) stated that at least three earthquakes rupture identified between 3.6 ka to 15 ka with an estimated long-term slip rate of 1.0 mm/y for Kalafat Fault, between 2.0 ka and 7.9 ka with an estimated long-term slip rate of 0.6 mm/y for Yavansu Fault. According to their results, the recurrence interval did not follow a uniform trend like other active faults in Western Anatolia (e.g., Kürçer et al, 2019). For these reasons, the possibility of triggering of these faults, which have not produced earthquake for a long time, due to the Samos earthquake should be examined.…”

The September 26, 2019 Silivri Earthquake (Mw=5.6), NW Türkiye

“…The Marmara Region has been characterized by high seismic activity with tens of devastating large earthquakes in both historical (Figure 1a) and instrumental period (Figure 1b) [1,2,3,4,5]. The trench studies have confirmed the high seismic activity [6,7,8,9,10,11]. The high seismic activity has been generated by the North Anatolian Fault Zone (NAFZ) which extends as three main fault strands, the Northern, Middle and Southern strands [12,13,14] (Figure 1a).…”

Segmentation and Holocene Behavior of the Middle Strand of the North Anatolian Fault (NW Turkey)

“…These strands could together accommodate as much as 25% of the total slip of the NAF (Armijo et al., 2002; Flerit et al., 2003), with slip rates between 7 and less than 1 mm/yr on the MNAF estimated with geodetical (Ergintav et al., 2014; Özbey et al., 2021; Reilinger et al., 2006) and geological data (Gasperini et al., 2011; Özalp et al., 2013; Vardar et al., 2014). While the SNAF experienced a Mw 7.2 earthquake in 1953 (Ketin & Rösli, 1953; Kürçer et al., 2008, 2019), no major earthquake ruptured the MNAF during the instrumental period, and the seismicity of the MNAF zone during the last eight decades does not include more than a couple of earthquakes larger than Mw 5. The microseismicity recently recorded has been mostly located west of Iznik Lake and around the Gulf of Gemlik, while the other segments in the east have been characterized by much fewer events and appear quiescent compared with the neighboring NAF strands (Baris et al., 2002; Gürbüz et al., 2000; Öztürk et al., 2009; Tsukuda et al., 1988).…”