caa a22 4500 606150129 CHVBK 20210128100537.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00531-015-1144-8 doi (NATIONALLICENCE)springer-10.1007/s00531-015-1144-8 The role of sediment composition and behavior under dynamic loading conditions on slope failure initiation: a study of a subaqueous landslide in earthquake-prone South-Central Chile [Elektronische Daten] [Gauvain Wiemer, Jasper Moernaut, Nina Stark, Philipp Kempf, Marc De Batist, Mario Pino, Roberto Urrutia, Bruno de Guevara, Michael Strasser, Achim Kopf] Subaqueous slope failure mechanisms are still poorly understood partly because they are difficult to study due to the remote location of submarine landslides. Landslides in lakes are smaller in size and more readily accessible and therefore represent a good alternative to their marine counterparts. Lake Villarrica, located in South-Central Chile, experienced significant slope failure and serves here as an exemplary study area for subaqueous landslide initiation mechanisms in tectonically active settings. Coring and CPTU testing were undertaken with the MARUM free-fall CPTU deployed adjacent to the coring sites where all lithological units involved in the slope failure were sampled. Using geotechnical methods such as pseudo-static factor of safety analysis and cyclic triaxial testing, three types of soils (i.e., diatomaceous ooze, volcanic ash, and quick clay) were analyzed for their role in slope failure, and earthquake shaking was identified as the primary trigger mechanism. The investigated landslide consisted of two distinct phases. During the first phase, slope failure was initiated above a tephra layer. In the second phase, retrogression led to the shoreward extension of the slide scarp along a second failure plane located in a stratigraphically deeper, extremely sensitive lithology (i.e., quick clay). Results show that liquefaction of buried tephra layers was unlikely, but such layers might still have contributed to a reduction in shear strength along the contact area with the neighboring sediment. Furthermore, cyclic shaking-induced pore pressure in diatomaceous ooze may be similar to that in granular soils. We generally infer that failure mechanisms observed in this study are equally important for landslide initiation in submarine settings as diatomaceous ooze intercalated with volcanic ash may be abundantly present along active continental margins. Springer-Verlag Berlin Heidelberg, 2015 Landslide nationallicence Earthquake shaking nationallicence Tephra nationallicence Quick clay nationallicence Diatomaceous ooze nationallicence CPT nationallicence Cyclic loading nationallicence Wiemer Gauvain MARUM, Centre for Marine Environmental Sciences, Bremen, Germany aut Moernaut Jasper Geological Institute, ETH Zürich, Zurich, Switzerland aut Stark Nina Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA aut Kempf Philipp Renard Centre of Marine Geology, Ghent University, Ghent, Belgium aut De Batist Marc Renard Centre of Marine Geology, Ghent University, Ghent, Belgium aut Pino Mario Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile aut Urrutia Roberto Centro EULA, Universidad de Concepción, Concepción, Chile aut de Guevara Bruno BENTOS, Santiago, Chile aut Strasser Michael Geological Institute, ETH Zürich, Zurich, Switzerland aut Kopf Achim MARUM, Centre for Marine Environmental Sciences, Bremen, Germany aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/5(2015-07-01), 1439-1457 1437-3254 104:5<1439 2015 104 531 https://doi.org/10.1007/s00531-015-1144-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-015-1144-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wiemer Gauvain MARUM, Centre for Marine Environmental Sciences, Bremen, Germany aut NATIONALLICENCE 700 1- Moernaut Jasper Geological Institute, ETH Zürich, Zurich, Switzerland aut NATIONALLICENCE 700 1- Stark Nina Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA aut NATIONALLICENCE 700 1- Kempf Philipp Renard Centre of Marine Geology, Ghent University, Ghent, Belgium aut NATIONALLICENCE 700 1- De Batist Marc Renard Centre of Marine Geology, Ghent University, Ghent, Belgium aut NATIONALLICENCE 700 1- Pino Mario Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile aut NATIONALLICENCE 700 1- Urrutia Roberto Centro EULA, Universidad de Concepción, Concepción, Chile aut NATIONALLICENCE 700 1- de Guevara Bruno BENTOS, Santiago, Chile aut NATIONALLICENCE 700 1- Strasser Michael Geological Institute, ETH Zürich, Zurich, Switzerland aut NATIONALLICENCE 700 1- Kopf Achim MARUM, Centre for Marine Environmental Sciences, Bremen, Germany aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/5(2015-07-01), 1439-1457 1437-3254 104:5<1439 2015 104 531