Modeling tsunami-tide interaction in Puget Sound

Presentation Abstract

The Puget Sound region is under the threat of tsunami waves generated by large earthquakes in both the Cascadia Subduction Zone off the Pacific Coast and faults inside the sound. Over the past decades, quite a few numerical modelling studies have been conducted to simulate tsunami wave propagation and associated coastal inundation in Puget Sound. These modelling studies were based on depth-averaged 2-D hydrodynamic models, in which the tidal forcing was mostly neglected as an approximation and simplification. However, tides can have an increasing effect on tsunami wave propagation especially in estuarine and coastal regions where water circulation is heavily influenced by tides. In fact, Puget Sound experiences large tidal ranges (>4m) and strong tidal currents (>3 m/s) in many places, which may deviate the actual tsunami wave propagation and inundation patterns from earlier model predictions. It is thus important to investigate how tsunami-tide interaction will modulate tsunami waves in Puget Sound. Here we present our modelling study on simulating tides and tsunami waves together in Puget Sound using a high-resolution hydrodynamic model. The example tsunami case simulated was based on the water surface and sea bottom deformation information for the M9.0 Cascadia Subduction Zone Earthquake (L1 scenario). A series of model sensitivity tests with initial seafloor deformation occurred at various tidal stages were conducted to examine the dynamic interactions between tides and tsunami waves. Detailed model result analyses and major findings will be presented.

Session Title

Posters: Climate Change: Impacts, Adaptation, & Research

Conference Track

SSE18: Posters

Conference Name

Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)

Document Type

Event

SSEC Identifier

SSE18-12

Start Date

5-4-2018 11:30 AM

End Date

5-4-2018 1:30 PM

Type of Presentation

Poster

Genre/Form

presentations (communicative events)

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Subjects – Topical (LCSH)

Tsunamis--Washington (State)--Puget Sound--Simulation methods

Geographic Coverage

Puget Sound (Wash.); Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

Text

Language

English

Format

application/pdf

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Apr 5th, 11:30 AM Apr 5th, 1:30 PM

Modeling tsunami-tide interaction in Puget Sound

The Puget Sound region is under the threat of tsunami waves generated by large earthquakes in both the Cascadia Subduction Zone off the Pacific Coast and faults inside the sound. Over the past decades, quite a few numerical modelling studies have been conducted to simulate tsunami wave propagation and associated coastal inundation in Puget Sound. These modelling studies were based on depth-averaged 2-D hydrodynamic models, in which the tidal forcing was mostly neglected as an approximation and simplification. However, tides can have an increasing effect on tsunami wave propagation especially in estuarine and coastal regions where water circulation is heavily influenced by tides. In fact, Puget Sound experiences large tidal ranges (>4m) and strong tidal currents (>3 m/s) in many places, which may deviate the actual tsunami wave propagation and inundation patterns from earlier model predictions. It is thus important to investigate how tsunami-tide interaction will modulate tsunami waves in Puget Sound. Here we present our modelling study on simulating tides and tsunami waves together in Puget Sound using a high-resolution hydrodynamic model. The example tsunami case simulated was based on the water surface and sea bottom deformation information for the M9.0 Cascadia Subduction Zone Earthquake (L1 scenario). A series of model sensitivity tests with initial seafloor deformation occurred at various tidal stages were conducted to examine the dynamic interactions between tides and tsunami waves. Detailed model result analyses and major findings will be presented.