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H G F E
D
C
B
A
Figure 1.4: Dock locations and aerial view of the Crescent City harbor prior to 2006 Event.
Arrow indicates the direction of the in the port triggered by the tsunami.
theory. Most numerical codes used for tsunami inundation solve depth–averaged equa-tions,
which may not always be applicable for “intermediate” free surface waves, i.e.
when the waveheight to wave length is less 0.05. Given the importance of this events
both for validation of hydrodynamic codes and for assessing the impact of even small
tsunamis, it will be described in greater details.
1.2.2 Summary of Eyewitness Accounts from 15 November 2006
Event for the Crescent City Harbor
Around 11 a.m. PST, on 15 November 2006, the Crescent City, California Harbor Con-trol
and Emergency offices received a warning for possible strong tsunami surges which
were expected to arrive around 11:30 a.m. (19:30 UTC). Because the tsunami had been
expected to be relatively minor, a full evacuation was not ordered, but rather targeted
18
Object Description
| Title | Deterministic and probabilistic tsunami studies in California from near and farfield sources |
| Author | Uslu, Burak |
| Author email | uslu@usc.edu; burak.uslu@noaa.gov |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Civil Engineering |
| School | Viterbi School of Engineering |
| Date defended/completed | 2007-09-21 |
| Date submitted | 2008 |
| Restricted until | Unrestricted |
| Date published | 2008-10-30 |
| Advisor (committee chair) | Synolakis, Costas E. |
| Advisor (committee member) |
Bardet, Jean-Pierre Okal, Emile A. Moore, James Elliott, II |
| Abstract | California is vulnerable to tsunamis from both local and distant sources. While there is an overall awareness of the threat, tsunamis are infrequent events and few communities have a good understanding of vulnerability. To quantitatively evaluate the tsunami hazard in the State, deterministic and probabilistic methods are used to compute inundation and runup heights in selected population centers along the coast.; For the numerical modeling of tsunamis, a two dimensional finite difference propagation and runup model is used. All known near and farfield sources of relevance to California are considered. For the farfield hazard analysis, the Pacific Rim is subdivided into small segments where unit ruptures are assumed, then the transpacific propagations are calculated. The historical records from the 1952 Kamchatka, 1960 Great Chile, 1964 Great Alaska, and 1994 and 2006 Kuril Islands earthquakes are compared to modeled results. A sensitivity analysis is performed on each subduction zone segment to determine the relative effect of the source location on wave heights off the California Coast.; Here, both time-dependent and time-independent methods are used to assess the tsunami risk. In the latter, slip rates are obtained from GPS measurements of the tectonic motions and then used as a basis to estimate the return period of possible earthquakes. The return periods of tsunamis resulting from these events are combined with computed waveheight estimates to provide a total probability of exceedance of given waveheights for ports and harbors in California. The time independent method follows the practice of past studies that have used Gutenberg and Richter type relationships to assign probabilities to specific tsunami sources.; The Cascadia Subduction Zone is the biggest nearfield earthquake source and is capable of producing mega-thrust earthquake ruptures between the Gorda and North American plates and may cause extensive damage north of Cape Mendocino, to Seattle. The present analysis suggests that San Francisco Bay and Central California are most sensitive to tsunamis originating from the Alaska and Aleutians Subduction Zone (AASZ). An earthquake with a magnitude comparable to the 1964 Great Alaska Earthquake on central AASZ could result in twice the wave height as experienced in San Francisco Bay in 1964.; The probabilistic approach shows that Central California and San Francisco Bay have more frequent tsunamis from the AASZ, while Southern California can be impacted from tsunamis generated on Chile and Central American Subduction Zone as well as the AASZ. |
| Keyword | assessment; California; hazard; model; probability; tsunami |
| Geographic subject | capes: Kamchatka; islands: Kuril Islands; fault zones: Cascadia Subduction Zone |
| Geographic subject (state) | California; Alaska |
| Geographic subject (country) | Chile |
| Coverage date | 1952/2008 |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m1706 |
| Contributing entity | University of Southern California |
| Rights | Uslu, Burak |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | cisadmin@lib.usc.edu |
| Filename | etd-uslu-2434 |
| Archival file | uscthesesreloadpub_Volume40/etd-uslu-2434.pdf |
Description
| Title | Page 33 |
| Contributing entity | University of Southern California |
| Repository email | cisadmin@lib.usc.edu |
| Full text | H G F E D C B A Figure 1.4: Dock locations and aerial view of the Crescent City harbor prior to 2006 Event. Arrow indicates the direction of the in the port triggered by the tsunami. theory. Most numerical codes used for tsunami inundation solve depth–averaged equa-tions, which may not always be applicable for “intermediate” free surface waves, i.e. when the waveheight to wave length is less 0.05. Given the importance of this events both for validation of hydrodynamic codes and for assessing the impact of even small tsunamis, it will be described in greater details. 1.2.2 Summary of Eyewitness Accounts from 15 November 2006 Event for the Crescent City Harbor Around 11 a.m. PST, on 15 November 2006, the Crescent City, California Harbor Con-trol and Emergency offices received a warning for possible strong tsunami surges which were expected to arrive around 11:30 a.m. (19:30 UTC). Because the tsunami had been expected to be relatively minor, a full evacuation was not ordered, but rather targeted 18 |
