SCIENTISTS CREATE HIGH-RESOLUTION COASTAL RELIEF MODELS FOR IMPROVED TSUNAMI FORECASTING

Oct. 12, 2006 — A team of scientists is contributing a crucial step in NOAA's effort to prepare U.S. coastal communities for tsunami and storm-driven flooding. Scientists with the NOAA National Geophysical Data Center and the Cooperative Institute for Research in Environmental Sciences—both based in Boulder, Colo.—are creating high-resolution digital elevation models, or DEMs, designed to improve forecasting for early tsunami warning systems. The DEMs are constructed from near-shore seafloor depth and land elevation data to create detailed representations of coastal relief. They provide the underlying framework necessary to accurately forecast the magnitude and extent of coastal flooding during a tsunami event. (Click NOAA image for larger view of digital elevation model, or DEM, for Myrtle Beach, S.C. Click here for high resolution version. Please credit “NOAA.”)

Since the effort started early this year, the team has created DEMs for the coastal communities of: Myrtle Beach, S.C.; Cape Hatteras, N.C.; Port San Luis, Calif.; Dutch Harbor and Sand Point, Alaska, and San Juan and Mayaguez, Puerto Rico. They expect to complete more than 100 DEMS for U.S. coastal communities in the coming years. Completed DEMS, with accompanying graphics and documentation, are available online.

"Development of the DEMs is one of a series of collaborative efforts within NOAA to achieve the best possible Tsunami Warning System for the country." said Lisa Taylor, NGDC project manager. "The system is structured to provide disaster planners with the most accurate information possible, so that they can make informed decisions in the event of a tsunami."

The new DEMs represent the relief of the coastal zone in fine detail, depicting topographic features as small as 100 feet across. NGDC works with other federal, state and local agencies, as well as academia and the private sector to acquire the best available near-shore data to create a DEM. The data are shifted to the vertical reference of Mean High Water for modeling "worst-case scenario" flooding events.

"Near the shoreline, all tsunamis are sensitive to minor variations in seafloor and land topography, increasing in height as they approach the coast," said Barry Eakins, CIRES research scientist. "Better understanding of the relief of the coastal zone is, therefore, critical to predicting how a tsunami will flood coastal communities."

Once a DEM is finished, it is delivered to the NOAA Pacific Marine Environmental Laboratory in Seattle, Wash., where it is incorporated into tsunami model scenarios. These model scenarios simulate offshore earthquakes, the resulting tsunami movement across the ocean, and the magnitude and location of coastal flooding caused when the tsunami reaches the shore. Armed with these simulation results, NOAA's Tsunami Warning Centers can issue more accurate flooding forecasts in the event of an earthquake-generated tsunami. Taylor added that the coastal DEMs also will be useful for predicting storm surge damage from hurricanes and other natural events.

In 2007 NOAA, an agency of the U.S. Commerce Department, celebrates 200 years of science and service to the nation. Starting with the establishment of the U.S. Coast and Geodetic Survey in 1807 by Thomas Jefferson much of America's scientific heritage is rooted in NOAA. The agency is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and information service delivery for transportation, and by providing environmental stewardship of the nation's coastal and marine resources. Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners, more than 60 countries and the European Commission to develop a global monitoring network that is as integrated as the planet it observes, predicts and protects.

Relevant Web Sites
NOAA Tsunami Inundation Gridding Project

NOAA Pacific Marine Environmental Laboratory

NOAA Tsunami Portal

Media Contact:
John Leslie, NOAA Satellite and Information, (301) 713-1265