Multi-disciplinary earthquake researches in Western Turkey: Hints to select sites to study geochemical transients associated to seismicity

Inan S., ERTEKİN K., Seyis C., ŞİMŞEK Ş., Kulak F., Dikbas A., ...More

ACTA GEOPHYSICA, vol.58, no.5, pp.767-813, 2010 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 58 Issue: 5
  • Publication Date: 2010
  • Doi Number: 10.2478/s11600-010-0016-7
  • Journal Name: ACTA GEOPHYSICA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.767-813
  • Hacettepe University Affiliated: Yes


Warm and hot spring water as well as soil gas radon release patterns have been monitored in the Aegean Extensional Province of Western Turkey, alongside regional seismic events, providing a multi-disciplinary approach. In the study period of 20 months, seven moderate earthquakes with M (L) between 4.0 and 4.7 occurred in this seismically very active region; two earthquakes with magnitude 5.0 also occurred near the study area. Seismic monitoring showed no foreshock activity. By contrast, hydro-geochemical anomalies were found prior to these seismic events, each lasting for weeks. The anomalies occurred foremost in conjunction with dip-slip events and seem to support the dilatancy and water diffusion hypothesis. Increased soil gas radon release was recorded before earthquakes associated with strike-slip faults, but no soil radon anomalies were seen before earthquakes associated with dip-slip faults. Geochemical anomalies were also noticeably absent at some springs throughout the postulated deformation zones of impending earthquakes. The reason for this discrepancy might be due to stress/strain anisotropies.