Stress field estimation by the geoid undulations of the Samos-Kusadasi Bay and implications for seismogenic behavior


Oruç B. , Balkan E.

ACTA GEOPHYSICA, vol.69, no.3, pp.1137-1149, 2021 (Journal Indexed in SCI Expanded)

  • Publication Type: Article / Article
  • Volume: 69 Issue: 3
  • Publication Date: 2021
  • Title of Journal : ACTA GEOPHYSICA
  • Page Numbers: pp.1137-1149

Abstract

The strong earthquake with magnitude 6.9 occurred offshore at the northernmost edge of the Samos Island and was strongly felt in the north Aegean islands and İzmir metropolitan city. In this study, the effective elastic thicknesses of the lithosphere and seismogenic layer thickness were correlated with each other in order to understand the nature of the earthquakes. We determined that the upper and lower depth limits of seismogenic layer are in a range of 5–15 km, meaning that only the upper crust is mostly involved in earthquakes in the study area. The fact that seismogenic layer and effective elastic thicknesses are close to each other indicates that the earthquake potential may be within the seismogenic layer. Following that, we estimate the stress field from the geoid undulations as a proxy of gravity potential energy in order to analyze the amplitude and orientation of the stress vectors and seismogenic behavior implications. The discrete wavelet transform has been carried out to decompose the isostatic residual gravity anomalies into horizontal, vertical and diagonal detail coefficients. The results delineated edges of gravity anomalies that reveal some previously unknown features.