Estimation of The Seismic Hazard Parameters of The City of Antalya, Southwest Turkey


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Uçar F., Aktürk Ö., Eroğlu Azak T.

International Multidisciplinary Scientific GeoConference (SGEM2016), Albena, Bulgaria, 28 June - 07 July 2016, vol.1, no.3, pp.483-490

  • Publication Type: Conference Paper / Full Text
  • Volume: 1
  • Doi Number: 10.5593/sgem2016/b13/s05.061
  • City: Albena
  • Country: Bulgaria
  • Page Numbers: pp.483-490
  • Akdeniz University Affiliated: Yes

Abstract

Seismic hazard, an inevitable property of earthquakes, is the prediction of ground motion intensity levels of future earthquakes that may cause damage and loss through ground shaking, surface faulting, landslide, liquefaction etc. In recent years, a worldwide seismic hazard map was prepared by a group of more than 500 scientists participated in the Global Seismic Hazard Assessment Program (GSHAP). The Global Seismic Hazard Map (GSHM) proposed by the GSHAP, incorporates two main earthquake zones namely; Circum-Pacific Seismic Belt and Alpine-Himalayan Orogenic Belt. Turkey is located in the Alpine-Himalayan Orogenic Belt and subject to different levels of seismic hazard from moderate to high according to the GSHM. Antalya is one of the major cities of Turkey and nearly millions of tourists are visiting the city every year. The city is mostly located in the second degree earthquake zone according to the seismic zonation map of Turkey. The western part of the city is located in the first earthquake zone, while seismic hazard gradually decreases from west to east and the eastern part falls in the “earthquake free” zone known as Zone 5. The geological structure of the city and its vicinity is mostly composed of easily soluble calcareous rocks that could not resist to abrasion and are characterized by surface collapse and small or large sized dissolution voids on ground surface. Accordingly, estimation seismic hazard of Antalya is an important subject due to the seismic threats and geological structure of the region. In this study, the seismic source parameters to be utilized in the seismic hazard analyses for Antalya city were estimated using the novel Turkish earthquake catalogue. The study are is modelled with 5 area source zones that are established considering a circle with a radius of 250 km centered in Antalya city center. The boundaries of the area source zones are decided upon the te seismotectonic structure of the region. Accordingly, the magnitude recurrence parameters are calculated on the basis of the Gutenberg Richter relation. For the entire area source zones, the recurrence parameters a and b vary in the range of 3.24 - 4.61, and 0.66 - 0.97 respectively. Accordingly, the probability of occurrence of an earthquake with magnitude 5.0 or greater for the study region is 100 % in 50 years.   

KEYWORDS: Probabilistic Seismic Hazard, Attenuation, Seismicity, Karstic Terrain, Antalya.