Abstract
Turkey is located on active fault zones such as the East Anatolian Fault (EAF), the North Anatolian Fault (NAF) and the Anatolian-Aegean Subduction Zone (AASZ). Ground seismicity activities of the NAF zone are relatively active compared with other faults. Eleven high-intensity earthquakes have been produced on this fault zone since 1939. Whereas the EAF zone was relatively quiescent in the last century, on the basis of historical records, destructive seismic activities occurred on the EAF zone in the last two decades. In this study, the rupture reason of faults, updated active fault data, and seismic maps are presented briefly. Moreover, failure reasons and failure mechanism of conventional masonry structures damaged from seismic ground motions on the EAF zone are evaluated in detail. Possible solutions are suggested on the basis of seismic codes. For this purpose, EAF-sourced earthquakes, i.e. 2003 Bingöl, 2010 Kovancılar (Elazığ), 2011 Maden (Elazığ), 2011 Tabanlı (Van) and Edremit (Van) hit in last two decades on this fault are investigated. Failures of conventional masonry buildings triggered from these earthquakes are assessed. Statistical evaluation, damage of earthquakes and failure pattern are deeply investigated and revealed. Eventually, one of the most significant reasons of severe damage or collapse to masonry structures due to this seismicity is the inability to construct the structures according to the requirements of seismic codes.
1. Introduction
The location of Turkey in the Eastern Mediterranean is one of the most active seismic zones in the world. There are 203 events of seismic ground motion records with Mw ≥ 6.0 recorded within Turkey and the vicinity territory between 1900 and 2012 [1]. There are 326 separate faults, fault zones or combined system on the updated active fault maps of Turkey. The longest traced fault zones were divided into sections based on their productivity of earthquakes individually. Finally, 485 separate fault sections considered to have the potential to produce seismic ground motion were identified across Turkey (Fig. 1). Four different neotectonic regions (Fig. 1) were proposed by S¸ engor € [2,3] across Turkey: (1) North Anatolian region; (2) Eastern Anatolian contractional region; (3) Central Anatolian planar region; and (4) Western Anatolian extensional region.
8. Conclusions and final remarks
As a final remark, it has to be emphasized that the EAF is also active fault compared to the NAF. According to the updated seismic map, nine different faults are available on the EAF. Most of the fault ruptures are triggered by tectonic-sourced strike-slip movement. Unfortunately, rarely reported seismic activity is not associated with a certain tectonic reason. Moreover, landslide-sourced seismic activities were also observed in the past. This vague reason of movement on the fault trace changes the diversity of the failure reason of the structure stock. Many masonry structures were damaged severely or collapsed due to a variety of damage and collapse reasons. The depths of the EAF earthquakes are shallow, and this situation causes serious damages to masonry structures.
