Preliminary Observations and Assessment of Çanakkale-Ayvacık Earthquake Activity

Abstract

A project was begun to monitor earthquake activity at the southwest branch of the Biga Peninsula in Ayvacık and close surroundings beginning on 14 January 2017 with Mw=4.6 and continuing through 6 February 2017 with Mw=5.5 (Mw=5.5 Kandilli Observatory and Earthquake Research Institute -KOERI -, Mw=5.3 AFAD, Mw=5.4 ÇOMÜ). The region has active seismicity and includes portions of the significant tectonic elements of the northwest Aegean region. Due to the continuation of earthquake activity, in addition to permanent stations linked to the national networks (KOERI and AFAD) in the region 10 continuousform recording 3-component temporary stations were set up with the aim of observation for at least 1 year. The distances between these stations varied from 6 to 12 km. In addition to the intensity and continuity of microearthquake activity in the region, and the inclusion of geothermal fields in the region, the necessity to investigate the seismotectonic character of the region in detail came to the agenda. Together with permanent stations belonging to national observatories in the study area, the station density was insufficient to reveal these details. As a result, data from both national network and temporary stations will contribute to understanding the tectonic character of the region. When temporary stations at close proximity to the main shock and epicenter distribution are compared with the national network primary results indicate there were significant improvements in identifying microearthquakes especially and in determining their locations. Additionally, and in source mechanism solutions belonging to earthquake data with moderate magnitude, faulting with a dominantly NW-SE oriented normal offset component was observed. This study aims to reveal the time and spatial distribution, frequency content and source mechanisms for earthquakes occurring in the southwest of the Biga Peninsula near Ayvacık and surroundings, in addition to determining a detailed velocity model with local tomography.

Hydrogeochemical and isotopic monitoring of the Kestanbol geothermal field (Northwestern Turkey) and its relationship with seismic activity

“…The NAFZ is composed of a series of right-lateral strike-slip segments extending from eastern Anatolia to the northern Aegean Sea (Ketin, 1948;McKenzie, 1972;Seyitoglu et al, 2016). The NAFZ bifurcates into three branches in the Marmara Region (Dewey and Sengor, 1979;Sengor et al, 1985;Barka, 1997;Gurer et al, 2003;Seyitoglu et al, 2016;Bekler and Demirci, 2018).…”

“…The north branch of the NAFZ begins southeast of Lake Sapanca passes through Izmit Gulf, Marmara Sea and Saros Gulf (Sengor et al, 1985;Barka and Kadinsky-Cade, 1988;Herece, 1990;Barka, 1992;Kurcer et al, 2008;Seyitoglu et al, 2016). The central branch follows the path southeast of Lake Sapanca and runs south of Geyve, Pamukova and Lake Iznik extending along the south coast of the Marmara Sea (Kocyigit, 1988;Barka, 1997;Kurcer et al, 2008) and the south branch separates from the central branch near Pamukova and extends in SW-NE direction via Yenisehir, Bursa, Ulubat, Gonen, and Yenice to the Edremit Gulf (Herece, 1990;Yaltirak, 2002;Bekler and Demirci, 2018). The recurrence intervals of earthquakes in the Marmara region affected by the north branch of the NAFZ have short time intervals of 150-300 years, while the central branch is currently a seismic gap and the south branch has a longer earthquake recurrence interval compared to the north branch (Ikeda et al, 1991;Rockwell et al, 2001;Hartleb et al, 2006;Sozbilir et al, 2018).…”