Landslide Investigation Using Transient Electromagnetic Method (TEM): A Case Study on Al-Ja'ydyya- Salhuob Landslide / Jordan

Abstract

In this study, Transient Electromagnetic (TEM) geophysical method was used at Al-Ja'ydyya- Salhuob landslide located along Amman- Irbid - Jerash highway aiming at investigating the subsurface layering's, thicknesses and to map the subsurface failure detachments and internal structures of landslide. Seventeen TEM Soundings were conducted to cover the study area. The interpreted TEM models suggests three to four principle subsurface units that are prevailing in the study area: The upper surface unit with resistivity 50-100 Ohm . m and thickness is ranging from 15m - 25m correlates with colluvial deposits. The second subsurface unit is interpreted to be a Clayey marl and Chalky marl and it has a resistivity range of  8-15 Ohm . m and has thickness in the range of 2 - 4m. This conductive unit were mapped throughout the whole study area. It is expected that this layer has a very significance role for rock sliding and mass movement.  The third subsurface resistive (>200 Ohm . m) unit is highly correlated with borehole logs and interpreted as a highly massive fractured limestone. The four subsurface unit is a  very low resistivity unit. It was detected beneath the whole study area  especially  the northern Salhoub landslide. It is interpreted as a saturated fractured limestone unit or marl, chalky filling fractured limestone. The internal subsurface fractures and boundaries of landslides were delineated and were found to be coincident with surface outcropped fractures. The slippage failure surfaces were delineated and mapped and shown clearly in The 2-D  E-W and NW-SE TEM models.

Keywords: Transient Electromagnetic (TEM), Al-Ja'ydyya- Salhuob Landslide, Jordan