HR: 11:50h
AN: S52A-07    [Abstracts]
TI: Development of Rapid Seismic Monitoring Procedures for Incorporation into the Caribbean Tsunami Warning System
AU: * Huerfano, V A
EM: victor@midas.uprm.edu
AF: Puerto Rico Seismic Netork UPRM - Geology, PO Box 9017, Mayaguez, PR 00681, United States
AU: von Hillebrandt, C G
EM: christa@midas.uprm.edu
AF: Puerto Rico Seismic Netork UPRM - Geology, PO Box 9017, Mayaguez, PR 00681, United States
AU: Mendoza, C
EM: cmendoza@geociencias.unam.mx
AF: UNAM, Jiriquilla, QRO, Campus, Mexico
AB: "Middle America", the geographic area between North and South America, including the Caribbean, has been a site of great plate tectonic activity in the most recent 35 million years. The region continues to be highly geologically active today as the Caribbean tectonic plate advances to the east, interacting with the North American and South American plates. Type examples of many of the salient features of plate tectonics—subduction zones, deep trenches, transform faults, pull-apart basins, subduction-to-strike-slip transitions, subduction-related volcanism, and volcano-free subduction zones—exist in a relatively small geographical area. The circum-Caribbean region has a documented history of destructive earthquakes and large damaging tsunamis that have affected coastal areas, including the events of Virgin Islands in 1867 and Mona Passage in 1918. These tsunamis have been triggered by large earthquakes that deformed the ocean floor. Tsunami waves originating in the prominent fault system around the Caribbean are considered to pose a near-field hazard because they can reach populated coastal areas within a few minutes after the earthquake. Because of this situation, the need to establish a system of rapid notification for tsunami alerting in the Caribbean has been recognized by emergency management agencies and the scientific community. In the wake of the December 26, 2004 devastating earthquake and tsunami in Indonesia, attention has been focused worldwide on the establishment of local and regional tsunami warning systems. The objective of the monitoring component of the Caribbean tsunami warning system under development in the Puerto Rico Seismic Network since 2000 is to detect, inform and confirm as rapidly and accurately as possible potential tsunamigenic events. In this presentation, we will describe the application of waveform analysis procedures for the rapid identification of shallow earthquake source parameters (geometry and size) in the Caribbean using three-component digital broadband records recorded at local and regional distances. For locally-recorded events, a grid-search method is investigated that uses the entire wave train recorded at multiple stations. A comparative search is conducted between observed and theoretical amplitude spectra at frequencies up to the corner frequency of the recording instrument to identify the best-fitting strike, dip, rake, and focal depth. In the regional procedure, a formal moment-tensor inversion scheme is used to derive the focal mechanism that best reproduces the waveforms recorded at a single or multiple stations.
DE: 3070 Submarine landslides
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
DE: 7294 Seismic instruments and networks (0935, 3025)
DE: 8107 Continental neotectonics (8002)
DE: 8123 Dynamics: seismotectonics
SC: Seismology [S]
MN: 2007 Joint Assembly