Simulation of paleotsunamis in Puget Sound, Washington
Andrew Moore2001, Abstract of the International …
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Abstract
This study aims to reproduce the tsunami that occurred 1100 years ago in Puget Sound reported by recent paleoseismological studies, using a finite difference model based on nonlinear shallow water theory. The study refines the estimates of run-up height, flow depth, and current velocity at these sites made by Moore (1993) and Dinkelman and Holmes (1993), using a high-resolution model that explicitly allows for coastal flooding and drying. The model is also used to estimate the spatial patterns of tsunami propagation and coastal inundation throughout Puget Sound for this earthquake scenario. When combined with existing field observations of paleotsunamis and ground movement, the simulations will help to constrain the earthquake mechanism. They will also help guide the search for additional geological evidence of this event.
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Geophysical Research Letters, 2002
Recent paleoseismic and geologic studies indicate that a tsunami occurred 1100 years ago in Puget Sound. This study aims to reproduce and validate the model tsunami, using a finite difference model based on nonlinear shallow water theory and abathymetry/topography computational grid that takes into account the 1-meter rise in sea level that has occurred in the region during the past 1100 years. Estimates of tsunami height, the extent of inundation, and the current velocity pattern are provided at the northern head of Cultus Bay, Whidbey Island, where paleotsunami sand deposits have been found. The model demonstrates that a tsunami generated when the background water level was at mean high water or above could have surged across the then-existing coastal marsh, penetrated the full length of the shallow bay, and deposited the observed sand layers.
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Quaternary Research, 2000
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Natural Hazards, 2013
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Distribution and sedimentary characteristics of tsunami deposits along the Cascadia margin of western North America
Sedimentary Geology, 2007
Tsunami deposits have been found at more than 60 sites along the Cascadia margin of Western North America, and here we review and synthesize their distribution and sedimentary characteristics based on the published record. Cascadia tsunami deposits are best preserved, and most easily identified, in low-energy coastal environments such as tidal marshes, back-barrier marshes and coastal lakes where they occur as anomalous layers of sand within peat and mud. They extend up to a kilometer inland in open coastal settings and several kilometers up river valleys. They are distinguished from other sediments by a combination of sedimentary character and stratigraphic context. Recurrence intervals range from 300-1000 years with an average of 500-600 years. The tsunami deposits have been used to help evaluate and mitigate tsunami hazards in Cascadia. They show that the Cascadia subduction zone is prone to great earthquakes that generate large tsunamis. The inclusion of tsunami deposits on inundation maps, used in conjunction with results from inundation models, allows a more accurate assessment of areas subject to tsunami inundation. The application of sediment transport models can help estimate tsunami flow velocity and wave height, parameters which are necessary to help establish evacuation routes and plan development in tsunami prone areas.
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Tsunami Hazard Assessment of the Northern Oregon Coast: A Multi-Deterministic Approach Tested at Cannon Beach, Oregon
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Bulletin of the Seismological Society of America, 2012
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SCIENCE OF TSUNAMI HAZARDS Journal of Tsunami Society International Volume 32 Number 4 2013 LATE HOLOCENE TSUNAMI DEPOSITS AT SALT CREEK, WASHINGTON, USA
2013
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