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Ultra High-resolution Reflection Seismic Imaging of Quick-clay Landslides in South-West Sweden
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 74th EAGE Conference and Exhibition incorporating EUROPEC 2012, Jun 2012, cp-293-00085
- ISBN: 978-90-73834-27-9
Abstract
Results from two nearly perpendicular high-resolution reflection seismic lines over a quick-clay landslide scar are presented. The site is located on the shoreline of the Gta river in the southwest coast of Sweden. The Gta river is the source of drinking water for about 700,000 people. It follows an approximately 4 km wide fault zone. The site is known for its quick-clay formations and landslides. The data show excellent quality and help to image bedrock topography and internal layering above it down to about 100 m. The shallowest reflection is observed at about 20-30 m below the surface, it on-laps the bedrock, and is interpreted to originate from the contact between clay formations above and a sandy layer below. The continuity of the reflection becomes loosely defined at where the landslide scar occurs. This maybe an indication that there is a link between the reflection and landslides in the area; however, this requires further investigations. Reflections from the bedrock suggest a depression zone with its deepest point below the landslide scar. Deeper reflections are also observed in the data and may suggest a deeper depression zone or fault systems for which the Gta river is formed.