HR: 09:30h
AN: OS21A-06    [PDF]
TI: 1992-2002: Perspective on a decade of tsunami field surveys
AU: * Okal, E A
EM: emile@earth.nwu.edu
AF: Northwestern Univ., Locy Hall, Evanston, IL 60208 United States
AU: Synolakis, C E
EM: costas@mizar.usc.edu
AF: Dept. Civil Engineering, Univ. Southern Calif., Los Angeles, CA 90089 United States
AU: Borrero, J C
EM: jborrero@mizar.usc.edu
AF: Dept. Civil Engineering, Univ. Southern Calif., Los Angeles, CA 90089 United States
AU: Members of ITST, .
AF: All, over, the, world
AB: The past decade has seen the systematic deployment of international field survey teams (ITST), following damaging regional tsunamis. Fourteen such surveys have been carried out: Nicaragua (1992), Okushiri (1993), Mindoro (1994), Java (1994), Flores (1994), Kuriles (1994), Mexico (1995), Biak (1996), Chimbote (1996), PNG (1998), Izmit (1999), Fatu Hiva (1999), Vanuatu (1999), Peru (2001) and PNG (2002). In addition, similar techniques have been applied to the survey of important historical tsunamis such as Aleutian (1946) and Amorgos (1956). The primary goal of the field surveys is to obtain a reliable, quantitative dataset of run-up and inundation measurements, which can be used in simulation experiments based on hydrodynamic modeling, in order to unravel the mechanism of generation of the tsunami. One of the most important results obtained from the compilation of such datasets has been the emergence of the aspect ratio of the distribution of run-up in the near field as a most promising discriminant between generation by the seismic dislocation (e.g., Nicaragua; Peru, 2001; PNG 2002) and by an underwater slump (e.g., Aleutian 1946, PNG 1998). Surveying also reveals localized enhancement of run-up, controlled on a smaller scale by occasional underwater landslides (Flores, 1992), splashes against cliffs (Mexico, 1995; Peru, 2001) or interaction with steep coastal valleys (Okushiri, 1993). Field surveys have also provided insight into engineering and societal factors controlling the extent of human and property losses, such as coastal land use, building codes and materials, and public education and awareness. To foster the latter, the teams constantly repeat simple messages on tsunami mitigation during one-on-one interviews with local residents, as well as town meetings. In this respect, the successful self-evacuation at Bay Mairtele, Vanuatu in 1999 is a gratifying example of the value of education.
DE: 4564 Tsunamis and storm surges
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting