A potential landslide area investigated by 2.5D electrical resistivity tomography: case study from Canakkale, Turkey


Coskun N. , Cakir O. , Erduran M. , KUTLU Y. A. , CETINER Z. S.

ARABIAN JOURNAL OF GEOSCIENCES, cilt.9, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 9 Konu: 1
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1007/s12517-015-2026-x
  • Dergi Adı: ARABIAN JOURNAL OF GEOSCIENCES

Özet

Geophysical methods provide important tools to investigate the shallow earth. One of these methods is electrical resistivity tomography (ERT), which has the capability to provide spatial and volumetric information on both subsurface structures and property variations. Specifically, the ERT is an important tool to define the geometry and characteristics of landslides. In this study, we share our results for an electrical resistivity tomography survey that we conducted on a field where the city of Canakkale, Turkey has a plan to build a War Museum approximately 56 acres wide. The construction field under consideration presents potential landslide risks prominent with high slopes on especially the northeastern side of the area. Because of possible intense load on the ground anticipated from deployment of heavy artillery and also from construction sites, landslide risks in the field are significantly increased. Quaternary-aged alluvial formations consisting of unconsolidated clastic sediments cover the region. In order to investigate the area, we carried out 2.5-dimensional resistivity survey using a multi-channel, multi-electrode system along 16 profiles with a total length of 2016 m. Borehole information from ten close wells was used to aid the interpretation of resistivity sections. The results showed that the shallow electrical structure beneath the study area is multi-layered of which the second layer from the top has the lowest resistivity and then the resistivity values steadily increase with depth. The low resistivity in the second layer is likely caused by extra water injection into the system from relatively high topographic structures to the southeast and also from nearby water channel that partly perimeters the study area. The bottom of low resistivity layer exhibits potential landslide surface overriding the deeper slate bedrock with relatively high resistivity. The excess load after the planned construction may trigger catastrophic slip along this slip interface. Based on our observations, we proposed some protective measures to avoid the landslides in the considered area.