Tsunami hazard from lacustrine mass wasting in Lake Tekapo, New Zealand
Published:September 30, 2019
Joshu J. Mountjoy, Xiaoming Wang, Susi Woelz, Sean Fitzsimons, Jamie D. Howarth, Alan R. Orpin, William Power, 2019. "Tsunami hazard from lacustrine mass wasting in Lake Tekapo, New Zealand", Subaqueous Mass Movements and their Consequences: Assessing Geohazards, Environmental Implications and Economic Significance of Subaqueous Landslides, D.G. Lintern, D.C. Mosher, L.G. Moscardelli, P.T. Bobrowsky, C. Campbell, J. Chaytor, J. Clague, A. Georgiopoulou, P. Lajeunesse, A. Normandeau, D. Piper, M. Scherwath, C. Stacey, D. Turmel
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Lacustrine-tsunami risk from landslides can be significant yet for most locations globally the hazard remains unquantified. Lake Tekapo, in the tectonically active mountain belt of New Zealand's South Island, has been chosen to develop surveying and modelling techniques to assess the hazard from landslide tsunamis. Lake Tekapo is ideal for this study due to the high sedimentation rates, steep surrounds and the proximity to active faulting that indicate a high landslide potential. The shoreline tourist settlement and hydropower infrastructure mean the impact of any tsunami could be significant. In 2016 a survey was carried out to collect high-resolution (1 m grid) EM2040 multibeam bathymetry, high-resolution seismic reflection data (Boomer and chirp) and 6 m long sediment cores. These data reveal a diverse range of sedimentary processes in response to high sediment input and numerous landslides with varied styles of emplacement. For example, a one-off landslide initiated 40 m above the shoreline with debris deposits that have runout onto the lake floor to 100 m water depth contrasts with the Cass River delta on the western shore that has failed multiple times during the lake-basin infilling history. Landslide-generated tsunami scenarios are used to determine the relative hazard at different regions of the lake to guide development of a probabilistic tsunami model.
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Subaqueous Mass Movements and their Consequences: Assessing Geohazards, Environmental Implications and Economic Significance of Subaqueous Landslides
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The challenges facing submarine mass movement researchers and engineers are plentiful and exciting. This book follows several high-profile submarine landslide disasters that have reached the world's attention over the past few years. For decades, researchers have been mapping the world's mass movements. Their significant impacts on the Earth by distributing sediment on phenomenal scales is undeniable. Their importance in the origins of buried resources has long been understood. Their hazard potential ranges from damaging to apocalyptic, frequently damaging local infrastructure and sometimes devastating whole coastlines. Moving beyond mapping advances, the subaqueous mass movement scientists and practitioners are now also focussed on assessing the consequences of mass movements, and the measurement and modelling of events, hazard analysis and mitigation. Many state-of-the-art examples are provided in this book, which is produced under the auspices of the United Nations Educational, Scientific and Cultural Organisation Program S4SLIDE (Significance of Modern and Ancient Submarine Slope LandSLIDEs).