3D reflection seismic investigation over a quick-clay landslide scar in Lilla Edet, south-westernSweden
2012 (English)Conference paper, Abstract (Refereed)
This project is part of a multidisciplinary research projectsponsored by the Society of Exploration Geophysiciststhrough the Geoscientists Without Borders (GWB)program. The 3D P-wave seismic data were acquired over alandslide scar close to Lilla Edet in south-west Sweden.The survey area is located on the shoreline of a major riverthat follows a 4 km wide fault zone. The area is known forhosting unstable quick-clays that could potentially causelandslides. The main objective of the 3D seismic was todefine the bedrock topography and layering within the clayformation. The 3D seismic data will form a base model thatwill assist the interpretations of the other geophysical data,which were collected at the same location. The quality ofthe data is good and the top of the crystalline bedrock and acoarse layer within the clay formation were detected. Thedepth to the coarse layer could be correlated using existinggeotechnical boreholes. A similar north-northeast extendingridge shaped structure was found in the coarser layer and inthe bedrock topography. The top of the bedrock is,however, dipping about 15° towards north while the coarselayer in the clay formation is fairly flat. The coarse layer islocated approximately 20 m below the surface and the topof the bedrock reaches a maximum depth of about 120 m.The geometry of the coarse layer may be important for thedirection of fresh water flow, which can leach salt from theclays, creating unstable quick-clays, at the location of thelandslide area.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:uu:diva-286434DOI: 10.1190/segam2012-0644.1OAI: oai:DiVA.org:uu-286434DiVA: diva2:921529
SEG Las Vegas 2012 Annual Meeting