New interactive maps released by the California Geological Survey outline the Santa Barbara County areas that could be exposed to the risk of tsunami hazards.
The statewide maps are designed to help people develop evacuation plans, as well as assist counties and cities in identifying their tsunami hazards for response planning efforts, according to the CGS.
The online maps, published on the CGS website, allow people to enter an address or neighborhood to determine whether the property is within a tsunami hazard area.
Much of the county’s coastline is considered within tsunami hazard areas, including portions of Carpinteria, Montecito, Santa Barbara, Isla Vista, Goleta Point, Devereux Slough, Ocean Beach Park west of Lompoc and Guadalupe-Nipomo Dunes Preserve.
“Bottom line: If you’re near the coast and feel strong shaking from a local earthquake or get an official notification to evacuate, move inland or to a higher elevation as soon as possible,” Rick Wilson, head of the CGS Tsunami Program, said in a statement.
“A large tsunami surge might be fascinating to watch but you don’t want to be anywhere near it.”
According to the maps, the entirety of the Santa Barbara waterfront is in a hazard area that reaches to Highway 101. A portion of the zone extends north of the freeway, in an area bounded by Garden Street on the west, East Haley Street on the north and North Salsipuedes Street on the east.
The California Department of Conservation said new information on the maps include:
» The Santa Barbara Airport area saw both modest increases and decreases in the tsunami hazard. Most areas that saw a hazard increase are low-lying, undeveloped areas like wetlands or canals. The east-west airport runway saw a decrease in tsunami hazard.
» The tsunami hazard moderately increased in the Carpinteria and Santa Barbara areas based on “an improved understanding of tsunami sources and new modeling results.”
» The tsunami hazard remains the same for most other parts of the county.
On the map, a yellow area is within a tsunami hazard area while areas colored in green are outside the hazard area.
“If you are in the yellow hazard area after feeling an earthquake that lasts a long time, or you receive an official evacuation notification, evacuate by foot immediately to a green area,” according to the CGS website.
The tsunami hazard area maps include new data and improved computer modeling results, and replace the maps published by the CGS in 2009.
The maps show how far inland a surge of seawater might go in a “worst-case scenario,” and includes minor inland “buffers” to roads and landmarks to clarify where people could evacuate safely.
Buffer areas account for potential errors and uncertainties in the modeling, according to the CGS.
CGS, part of the state Department of Conservation, has issued tsunami hazard area maps for 13 coastal counties.
“Hazards management for geologic events such as tsunamis … is one of our department’s pillars, or cornerstones,” said Steve Bohlen, acting state geologist of California and head of CGS.
The maps incorporate lessons learned by Japan a decade ago during the 2011 Tōhoku-oki earthquake and tsunami, according to Bohlen.
“Japan utilized data from several hundred years of tsunami records in its planning, which seemed perfectly reasonable,” he said. “Then it was impacted by a once-a-millennium tsunami. So, we’re taking a very conservative approach and using a thousand-year scenario as the baseline for our new maps, hoping to avoid the tragic loss of life experienced in Japan.
“While damaging tsunamis are infrequent in California, they have and do happen. If you live on or visit the coast, you need to be aware of this potential hazard.”
The maps will inform California’s Hazard Mitigation Plan and emergency planning efforts so that state agencies, local governments and others can mitigate and respond to potential emergencies.
“We appreciate the collaboration with the Department of Conservation’s California Geological Survey to provide Californians who live, work or visit in a tsunami hazard area the tools they need to develop evacuation plans for themselves, their families and their businesses,” said Lori Nezhura, deputy director of Planning, Preparedness and Prevention at the state Office of Emergency Services.
More than 150 tsunamis have struck California since 1800, according to CGS.
“Most were barely noticeable, but a few have caused fatalities or significant damage,” CGS officials said.
The most destructive tsunami to hit California occurred in 1964. Several surges reaching more than 20 feet high swept into Crescent City in Del Norte County four hours after a magnitude 9.2 earthquake in Alaska. The tsunami killed 12 people and leveled much of the town’s business district.
A tsunami is defined as “a series of water surges or waves usually caused by an earthquake beneath the seafloor,” according to a report developed by the Earthquake Country Alliance, California Earthquake Authority and Cal OES.
Coastal areas are at risk of tsunamis, generated from earthquakes along faults or across the Pacific Ocean, the report’s authors said.
“If you are in a tsunami zone and feel an earthquake, move inland or to higher ground as soon as it is safe to move,” the report said.
— Noozhawk staff writer Brooke Holland can be reached at bholland@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.
