Geoelectrical Structure of the Avcılar Landslide Using VLF-EM Method

KARCIOĞLU G.

New Trends in Geophysics and Engineering 2018, İstanbul, Turkey, 7 - 09 November 2018, pp.1-4, (Full Text)

  • Publication Type: Conference Paper / Full Text
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.1-4
  • Istanbul University Affiliated: Yes

Abstract

The western part of the Küçükçekmece Lake in the Avcılar region is generally described with N-NW oriented faults, conductive tertiary formations and landslides creating distinctive conductivity anomalies.
The conductivity distribution in the study area is previously investigated only using 1D interpretation techniques by several researchers. In this study, near surface conductivity structure within the Avcilar landslide down to 25 m is investigated through VLF-EM and VLF-R methods in order to image Avcilar landslide in 2D.
The VLF data is collected along two overlapping SW-NE profiles. The first traverse is collected with 6.5m intervals and the data on the second traverse is collected with 3m intervals to obtain more information about the anomalous area determined in the first profile. Inıtial interpretations are realized using Karous-Hjelt filtering technique. Subsequently, the data is modeled using a 2D inversion algorithm with smoothing constraint.
Inversion results suggests, the clayey formations consisting the base of the landslide at ~20-25 depth, and a fluid rich water accumulation zone at the toe area of the landslide. Besides, the recovered geo-electrical models in this study are considerably different from the results of the previous studies that employed 1D interpretation methods.