Tsunami interaction with coastlines and elevation predictions /
by James Robert Houston.
Description
- Language(s)
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English
- Published
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1978.
- Summary
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The development is described of two numerical models that accurately simulate the propagation of tsunamis to nearshore regions and the interaction of tsunamis with coastlines. One of these models is a finite element model which uses a telescoping numerical grid to cover a section of the Pacific Ocean, including all eight islands of the Hawaiian Islands. The second model is a finite difference scheme that uses four rectilinear grids to cover most of the west coast of the continental United States. The finite element model solves linear and dissipationless long-wave equations. Such equations govern nearshore propagation in the Hawaiian Islands since the short continental shelf of the islands limits the time available for nonlinearities and dissipation to cause significant effects. The finite difference model solves nonlinear long-wave equations that include bottom stress terms which are important for the long continental shelf of the west coast of the United States. Both models are verified by hindcasting actual historical tsunamis and comparing the numerical model calculations with tide-gage recordings. A frequency of occurrence analysis of tsunami elevations at the shoreline in the Hawaiian Islands is described. This analysis is based upon local historical data with the finite element model used to interpolate between historical data recorded during the period of accurate survey measurements since 1946. Historical data recorded at Hilo, Hawaii, and dating to 1337 is used in conduction with data recorded since 1946 in Hilo and throughout the Hawaiian Islands to reconstruct elevations at locations in the islands lacking data prior to 1946. Frequency of occurrence curves are determined for the entire coastline of the Hawaiian Islands using these reconstructed elevations. Since most of the west coast of the United States lacks local data of tsunami activity, a frequency of occurrence analysis of tsunami elevations is based upon historical data of tsunami occurrence in tsunamigenic regions in addition to numerical model calculations. A generation and deep-ocean propagation numerical model is used to propagate tsunamis with varying intensities from locations throughout the Aleutian-Alaskan and Peru-Chile regions to a water depth of 500 meters off the west coast. The nearshore finite difference model propagates these tsunamis from the 500 meter depth to shore. The frequency of occurrence of combined tsunami and astronomical tide elevations is determined by an analysis involving the numerical superposition of tsunamis and local tides.
- Note
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Vita.
Typescript.
- Physical Description
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ix, 105 leaves :
ill. ;
28 cm.
Viewability