California plans new research on tsunami dangers
Within the next three years, the state of California plans to produce statewide land use planning maps of tsunami risk that will help coastal communities, harbor masters and port officials better prepare for dangerous waves.
The state released tsunami inundation maps in December 2009 that show potential flooding along the coast in a worst-case scenario, including from events that might occur only once in thousands of years, like tsunamis spurred by undersea landslides.
The new maps will show the risk from events likely to happen within the next few hundred years, said Rick Wilson, engineering geologist with the California Geological Survey.
In most cases, that will mean less extreme flood scenarios. For instance, the current inundation maps show water potentially reaching as far as two miles inland in Huntington Beach and Newport Beach. But for events likely to occur every 500 years or less, wave action would likely stop within 100 feet of the oceanfront, Wilson said.
The worst-case inundation maps are intended to be used to prepare for evacuations. Local communities might use the planning maps, on the other hand, to decide where to put schools, hospitals, police and fire stations, Wilson said.
The maps will also show where hazard zones lie within harbors and ports, and safe areas offshore where boats can be taken when a tsunami is imminent. That could limit economic losses in future events.
While harbor masters were generally well prepared for the surges that came from Japan, Wilson said there is a need for more public education about tsunami risks. For instance, some people were piloting their boats to or from shore when the surges hit.
"We could have had many more casualties during this event," Wilson said. (The only reported death was a man in Crescent City who was swept away while attempting to photograph the waves).
California receives about $1 million a year from the federal government through the National Tsunami Hazard Mitigation program to use for public education, preparation and research. The law authorizing the money sunsets in 2012.
-- Abby Sewell