28 March 1970 Gediz earthquake fault, western Turkey: palaeoseismology and tectonic significance

Late Holocene coseismic rupture and aseismic creep on the Bolvadin Fault, Afyon Akşehir Graben, Western Anatolia

“…On the other hand, the estimated recurrence interval for surface rupture earthquakes is 995 ± 45 years. This result best fits with a recurrence interval estimate of 910 ± 40 years on the Erdoğmuş Fault (Gediz) in the ASFS by Gürboğa et al (2013). The time since the last morphogenic (M > 6) earthquake for the Bolvadin Fault is 494 ± 45 years.…”

“…They suggest the occurrence of two surface faults after 1150 AD in Maltepe and before 760 AD in Çay trenches (Akyüz et al, 2006). On the other hand, Duman et al (2013) and Gürboğa (2013) conducted trench-based studies along the northwestern part of the ASFS. Duman et al (2013) described Holocene activity with at least five events which are associated with lateral strike slip faulting on the Çaysimav and Şaphane segments.…”

“…Duman et al (2013) described Holocene activity with at least five events which are associated with lateral strike slip faulting on the Çaysimav and Şaphane segments. Gürboğa (2013) identified two events (in 990 AD and 1020 AD) on the surface rupture of the 1970 Gediz earthquake (Ms: 7.2) and estimated the recurrence interval on the Erdoğmuş Fault as 910 ± 40 years which was unique along the ASFS. However, none of them detail aseismic creep on the studied faults.…”

Normal faulting in the Simav graben of western Turkey reassessed with calibrated earthquake relocations

“…The E dipping Aşkpaşa‐Muhipler fault zone, which ruptured during the 1970 Gediz earthquake, bounds the eastern slope of the Şaphanedağ yet is poorly defined in the landscape [ Ambraseys and Tchalenko , ]. The northern slope of Muratdağ is defined by a set of north dipping normal faults, of which the Erdoğmuş‐Hamamlar fault also ruptured during the 1970 earthquake [ Ambraseys and Tchalenko , ; Gürboğa , ].…”

“…Of particular interest to us are the M w 7.1 Gediz earthquake of 28 March 1970, which is among the largest continental normal faulting earthquakes recorded globally and the largest in western Turkey, and the M w 5.9 and M w 6.0 Demirci earthquakes of 23 and 25 March 1969, which are the next largest instrumental events in this region. The faults responsible for these older events remain unclear due in part to large epicentral uncertainties, and there have been controversial suggestions that basal, low‐angle detachment faults were involved [ Eyidoğan and Jackson , ; Braunmiller and Nábeělek , ; Seyitoğlu , ; Gürboğa , ]. Because the faulting is so poorly characterized, the risks posed to nearby cities are also little understood.…”