International Workshop of Active Tectonics and Seismicity of the Aegean Region with special emphasis on the 30 October 2020 Samos Earthquake (ASASE-2021), İzmir, Türkiye, 20 - 21 Mayıs 2021, ss.1-2, (Tam Metin Bildiri)
Samos Earthquake
(30.10.2020, Mw =
6.9) had catastrophic effects on the
Bayraklı district (within
Bornova Plain) of Izmir. 17 buildings completely collapsed, almost thousand building were heavily damaged due to the earthquake.
Bornova Plain is
an east-west trending tectonic depression developed within the
horst-graben system of
Western Anatolia. The
Bornova Plain was filled with the alluvium brought by the short, seasonal streams that reach the plain from the surrounding high masses. Seasonal changes in the flow regimes of these streams have created an inhomogeneous accumulation in horizontal and vertical directions. This thick accumulation of low S-wave velocity and intensity will amplify the earthquake waves. However, it should be noted that the basin topography of the plain will also have unwanted effects on earthquake waves.
3513 strong ground motion station located in the
Bayraklı district and on the coast of Izmir Bay measured the peak acceleration value
(PGA) of the earthquake as
0.108 g. Although the building stock of
İzmir does not differ from place to place, various analyzes have been made in the areas where the buildings collapsed after the earthquake was located to investigate the reasons for the collecting of demolitions in a
single area. In this context, an earthquake simulation was carried out for the soil under a collapsed building. In designing this earthquake simulation; Earthquake data
of 3513 strong-motion station, soil-bedrock
model of 3513 strong-motion station, soil-bedrock
model of a collapsed building were used. For this analysis, the soil-bedrock
model under the collapsed building was created by the inverse solution of single-point microtremor measurement. In summary, the study was carried out by deconvolved the 3513
strong-motion station earthquake data
to the bedrock interface located under the station and transferring this transported data
from the bedrock interface under the collapsed building to the soil layers and the ground surface. According to the findings obtained from this process, the soil under the collapsed building amplified the earthquake waves more than 2 times. Also, dynamic soil behavior during the earthquake moved away from linear behavior and showed non-linear behavior from an average depth of
55-60 m.