The site effects in Izmir Bay of October 30 2020, M7.0 Samos Earthquake

Altun, Selim
Çetin, Kemal Önder
Akgün, Mustafa
Askan Gündoğan, Ayşegül
Sezer, Alper
İpek, Yaprak
Gülerce, Zeynep
Ilgaç, Makbule
Özacar, Atilla Arda
Can, Gizem
Cakir, Elife
Söylemez, Berkan
El-Sayeed, Alaa
Zarzour, Moutasem
Bozyiğit, İrem
Tuna, Çağlar
Köksal, Duygu
Karimzadeh, Shaghayegh
Uzel, Bora
Karaali, Ediz
Due to the unique soil and morphological conditions prevailing in Izmir Bay basin, structural damage has been governed by site effects. Consistently, during October 30, 2020 M7.0 Samos Earthquake, which took place offshore of Samos Island, structural damage and life losses were observed to be concentrated in Bayrakli region of Izmir Bay, despite the fact that the fault rupture was at a distance of 65–75 km from the city of Izmir. Additionally, strong ground motions recorded in Izmir Bay showed unique site amplifications that were observed surprisingly at both rock and soil sites. Soil amplifications and duration elongations were mostly due to site effects governed by the response of very deep alluvial deposits of low plasticity. Similarly, due to very extensive faulting-induced fracturing and unusually stratified nature of rock sub-layers, unexpected long period amplifications were also observed at rock sites. These earthquake and site resonance effects were more pronounced in the period range of 0.5–1.5 s. When they were superposed with relatively coinciding natural period of 7–9 story residential buildings of Izmir City, it was concluded that the triple resonance effects among incoming rock ground motions, soil deposits, and the damaged buildings, amplified and prolonged the overall system response. Within the confines of this manuscript, the governing role of site effects leading to increased seismic demand was assessed, through a series of 1D equivalent linear, total stress-based site response assessments, the results of which clearly highlighted the variation of seismic demand in Izmir Bay.
Soil Dynamics and Earthquake Engineering


Evaluation of alluvial deposits in Gemlik basin in terms of earthquake codes.
Avşar, Ulaş; Doyuran, Vedat; Department of Geological Engineering (2006)
Gemlik County is located in the Marmara Region (NW Turkey), which has been affected by destructive earthquakes sourced from North Anatolian Fault System throughout its history. The bulk of the settlement rests on alluvial deposits of the Gemlik pull-apart basin. So, it is vital to investigate the foundation soils in this basin and the response of them to earthquakes. Many earthquake codes were established by the authorities in different countries of the world to estimate the possible ground shaking and seis...
Probabilistic assessment of the contribution of geotechnical factors on observed structural damage in Adapazarı and Düzce regions
Yıldızlı, Burak; Gülerce, Zeynep; Department of Civil Engineering (2019)
The 1999 Kocaeli and Düzce Earthquakes caused extensive damage to the structures in Adapazarı, Düzce and surrounding cities, leading to several attempts to estimate the damage states of the existing building stock using the data collected from these destructive events. Preliminary damage state prediction models that include the geotechnical earthquake engineering factors were developed for Adapazarı after the 1999 Kocaeli earthquake; however, validation exercises were not performed using the data collected ...
Probabilistic seismic hazard assessment for earthquake induced landslides
Balal, Onur; Gülerce, Zeynep; Department of Civil Engineering (2013)
Earthquake-induced slope instability is one of the major sources of earthquake hazards in near fault regions. Simplified tools, such as Newmark’s Sliding Block (NSB) Analysis are widely used to represent the stability of a slope under earthquake shaking. The outcome of this analogy is the slope displacement where larger displacement values indicate higher seismic slope instability risk. Recent studies in the literature propose empirical models between the slope displacement and single or multiple ground mot...
Site characterisation in north-western Turkey based on SPAC and HVSR analysis of microtremor noise
Asten, Michael W.; Askan Gündoğan, Ayşegül; Ekincioglu, E. Ezgi; Sisman, F. Nurten; Ugurhan, Beliz (2014-06-01)
The geology of the north-western Anatolia (Turkey) ranges from hard Mesozoic bedrock in mountainous areas to large sediment-filled, pull-apart basins formed by the North Anatolian Fault zone system. Duzce and Bolu city centres are located in major alluvial basins in the region, and both suffered from severe building damage during the 12 November 1999 Duzce earthquake (Mw = 7.2). In this study, a team consisting of geophysicists and civil engineers collected and interpreted passive array-based microtremor da...
Probabilistic seismic hazard assessment for east anatolian fault zone using planar source models
Menekşe, Akın; Gülerce, Zeynep; Department of Civil Engineering (2015)
The objective of this study is to perform probabilistic seismic hazard assessment (PSHA) using planar seismic source characterization models for East Anatolian Fault Zone (EAFZ) and to update the design ground motions to be used in the region. Development of planar seismic source models requires the definition of source geometry in terms of fault length, fault width, fault plane angles and segmentation points for each segment and associating the observed seismicity with defined fault systems. This complicat...
Citation Formats
S. Altun et al., “The site effects in Izmir Bay of October 30 2020, M7.0 Samos Earthquake,” Soil Dynamics and Earthquake Engineering, vol. 152, pp. 0–0, 2022, Accessed: 00, 2021. [Online]. Available: