Pacific Coastal & Marine Science Center
Tsunami Hazard Potential in the Caribbean
Tsunamis are among the world’s most destructive coastal hazards. The sharp increase in coastal population density, the intense development of harbors and urban infrastructure, and the exploitation of mineral resources in coastal areas, all set up a potential disaster of catastrophic proportions.
Tsunami events have been recorded in the Caribbean Sea since the 16th Century (Lander et al., 2002), and the number of tsunami casualties in the Caribbean exceeds that of the U.S. West Coast, Hawaii, and Alaska combined. There have been 91 reported tsunamis in the Caribbean basin since Europeans moved to the area, of which 27 events are very well documented and caused extensive damage and casualties. The most famous of these events include the:
The great Lisbon earthquake of 1755 created a tele-tsunami with 6 and 7 meter-high waves in the Lesser Antilles. Evidence for significant paleotsunamis is also found in the sediments of the Netherlands Antilles at 400-500 ybp, 1500 ybp and 3500 ybp (Scheffers and Kaletat 2001).
Although there have been deadly tsunamis in the NE Caribbean during the last century (1918: 42 persons and 100 missing; 1946: 1,790 persons by some reports), it is a repeat of the 1867 tsunami in the US Virgin Islands that may be most worrisome. A tsunami that followed within a few minutes of an earthquake in the Anegada Trough created a 6-9 meter high waves entering simultaneously St. Thomas’ Charlotte Amalie and St. Croix’s Christiansted Harbours. This event lifted the US Navy ship Monogahela onto a pier at Fredriksted, St. Croix.
The Caribbean Plate boundary is prone to tsunamis because it has all the tsunami-generating sources within a small geographical area as follows:
Impact of this work is intended to improve the safety of residents and to protect coastal resources in the Puerto Rico/Virgin Islands region with regard to earthquakes and tsunamis. By determining the likely hazards and their causative mechanisms, and by providing this information to government agencies and the public, we may aid in such activities as improvement of building codes, encouraging safer zoning, and assisting public education for response to hazards.
Products from this work will include:
10/1/2005 - 9/30/2010
We propose to carry out a multi-year effort to improve regional assessments of tsunami hazard potential in the Caribbean (Puerto Rico and Virgin Islands) by developing enhanced geological and geospatial information. Efforts would culminate in an improved hazard assessment product for the region as a model for future regional tsunami hazard assessment efforts elsewhere.
Activities would include coordinated development of source potential information from marine geophysical studies, modeling of tsunami propagation and runup, interpretation of onshore tsunami deposits to characterize hazard, and development of improved digital elevation models based on existing elevation data. The efforts are coordinated with broader hazard assessments (EHP) and multi-agency tsunami hazard assessment programs (NOAA), and with the University of Puerto Rico seismic and tsunami hazards center.
The activities recommended here complement, and do not duplicate, activities currently undertaken or proposed by the USGS Earthquake Hazard Program, NOAA, or the University of Puerto Rico. The technology to study the marine environment is highly specialized and requires unique tools and trained personnel. The unique capabilities of the CMG program include the acquisition of high-resolution, multi-channel seismic reflection data and multibeam bathymetric data, and coring. Sediment stability, strong ground motion, and seismic attenuation in the marine environment are often different from those encountered on land, because the sediments are saturated with water and sometimes with gas. This unique and integrated environment requires a multidisciplinary approach and the broad expertise of marine geologists.
The project consists of three tasks:
The first task will include sub-tasks such as:
The second task will incorporate detailed landslide studies (including dating), as well as earthquake recurrence rates, into a comprehensive probabilistic tsunami hazard assessment, and modeling specific earthquake and landslide tsunami sources and regional propagation patterns in the NE Caribbean. This task may also include modeling the effect of the Hispaniola and Puerto Rico trenches on the U.S. East Coast. Theoretical studies of landslide speed and basal friction for selected materials in conjunction with Landslide studies Incorporation of dynamic mudslide model will be explored. We would assist the University of Puerto Rico to improve flood maps for Puerto Rico and the Virgin Islands.
The third task will focus on:
The project builds on the broad expertise of scientists at all three CMGP centers. A joint project with NOAA-PMEL and the University of Puerto Rico has also been established to assess the relative tsunami threat to Caribbean, Atlantic, and Gulf of Mexico with the goals of prioritizing forecast models, optimizing DART buoy network location, identifing and guiding further investments in focus areas, providing public information on relative hazard, and providing guidance for operational warnings.
Geist, E. L. (2005), Rapid tsunami models and earthquake source parameters: Far-field and local applications, ISET Journal of Earthquake Technology, 42.
Geist, E. L., V. V. Titov, and C. E. Synolakis (2006), Tsunami: wave of change, Scientific American, 294, 56-63.
Geist, E. L., and T. Parsons (2006), Probabilistic analysis of tsunami hazards, Natural Hazards, 37, 277-314.
ten Brink, U., Twichell, D.K., Geist, E., Chaytor, J., Locat, J., Lee, H., Buczkowski, and Sansoucy, M., The current state of knowledge regarding potential tsunami sources affecting U.S. Atlantic and Gulf Coasts, USGS Administrative Reports, 2007.
ten Brink, U.S., Geist, E.L., Andrews, B.D., and Lynett, P., Submarine slides north of Puerto Rico and their tsunami potential, in Caribbean Tsunami Hazard, edited by A. Mercado and P. Liu, World Scientific Publishers, Singapore, p. 67-90, 2006.
ten Brink, U.S., Geist, E.L., and Andrews, B.D., Size distribution of submarine landslides and its implication to tsunami hazard in Puerto Rico, Geophysical Research Letters, 33, L11307, doi:10.1029/2006GL26125, 2006.
ten Brink, U.S., Vertical motions in the Puerto Rico trench and Puerto Rico and their cause, Journal of Geophysical Research, v. 110, B06404, doi:10.1020/2004JB003459, 2005.
National Oceanic and Atmospheric Administration (NOAA)/Office of Ocean Exploration/POC: Mclean, Craig