February 2, 2009
Digital elevation model, or DEM, of Santa Barbara, Calif.
High resolution (Credit: NOAA)
NOAA scientists have created a high-resolution digital elevation model, or DEM, of Santa Barbara, Calif., that simulates the effects of deadly tsunamis and coastal floods. The model enables scientists and emergency managers to develop life-saving plans to protect residents in Santa Barbara County and the nearby coastal communities of Ventura and Oxnard.
“These coastal digital elevation models help local emergency managers identify which areas of their communities are most vulnerable to tsunami waves and coastal flooding. In turn, they can dedicate their warning and response resources more efficiently and effectively,” said Lisa Taylor, project manager at NOAA’s National Geophysical Data Center which developed this DEM with the Cooperative Institute for Research in Environmental Science.
DEMs are detailed coastal relief maps constructed from near-shore sea floor depth and land elevation data. They provide a framework that allows scientists to forecast the magnitude and extent of coastal flooding caused by a tsunami or storm surge with greater accuracy.
The high-resolution DEMs are a crucial part of the U.S. Tsunami Forecast and Warning System. Since 2006, scientists have created models for 30 coastal communities with another 32 planned for the coming years.
Once a DEM is developed, it is sent to NOAA’s Pacific Marine Environmental Laboratory in Seattle, Wash., where it is incorporated into tsunami model scenarios. These scenarios simulate offshore earthquakes, the resulting tsunami and the magnitude and location of coastal flooding when the tsunami reaches the coast. With this information, the NOAA Tsunami Warning Centers can issue more accurate flooding forecasts if an earthquake triggers a tsunami, helping local emergency officials decide whether to issue population evacuations when a tsunami threatens.
In addition to threats from tsunamis generated across the Pacific Ocean, California faces other hazards such as active undersea fault zones and submarine landslides that are capable of creating less frequent, but possibly much larger, local tsunamis that will hit the coast quickly. The Santa Barbara DEM encompasses the massive submarine Goleta Landslide complex that could be prone to future failures and tsunami generation in the future.
The California Emergency Management Agency and the California Geological Survey are responsible for assessing tsunami hazards, delineating evacuation zones and promoting a culture of tsunami preparedness. Ultimately, this new relief model will be incorporated into the state’s tsunami inundation mapping process.
NOAA, along with its federal and state partners in the National Tsunami Hazard Mitigation Program, is implementing the Tsunami Warning and Education Act. This law authorizes and strengthens tsunami detection, forecasting, warning and mitigation.
NOAA understands and predicts changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.