Update: After the 8.2-magnitude earthquake struck the coast of Chile April 1, the Los Angeles Times reported small tsunami waves and "unusual water movement" arrived in La Jolla. The article states "the National Weather Service ended a tsunami advisory for the state of Hawaii around 7:25 a.m. (Wednesday). But the first waves connected to the South American earthquake to strike California may have hit La Jolla hours earlier, said Bill Knight, an oceanographer with the National Tsunami Warning Center based in Alaska." No tsunami warning has been issued for California.
By Ashley Mackin
Several San Diego safety and public service organizations — including the San Diego County Office of Emergency Services, San Diego Office of Homeland Security, City Council District 1 and San Diego Lifeguards — gathered March 26 at Kellogg Park in La Jolla Shores to recognize Tsunami Awareness Week, March 23-29, and announce the distribution of new maps that outline the risk of tsunami, as well as suggestions on what to do in the event of one.
“San Diego has 70 miles of coastline and it’s important for San Diegans to understand our risk for tsunami,” said Holly Crawford, the county’s Director of Emergency Services. “Today, we mailed 33,000 brochures to homes and businesses that tell — not only what to do before, during and after a tsunami — but depict a map of the worst tsunami-prone zones and potential evacuation routes where residents can flee in a case of a tsunami.”
Two kinds of tsunamis
San Diego susceptible to both near- source and distant-source tsunamis, Crawford explained. “In the event of an earthquake right off the coast (a near- source tsunami), we might only have 10- 15 minutes to respond. So we want people to know, if the earth shakes for 20 seconds ... you need to leave the coast, go to a place that’s at least 100 feet above sea level or at least two miles inland.”
A distant-source tsunami, which would take longer to reach San Diego and therefore allow more time to respond, is a more likely threat.
Senior Geological Engineer from the California Geological Survey Rick Wilson explained large magnitude earthquakes — such as the 9.2-magnitude earthquake off the coast of Alaska that generated a tsunami that reached California in 1964 — are more likely to happen in areas like Alaska and Japan than they are in southern California. However, the tsunamis generated by these larger earthquakes have the ability to travel farther.
“From a distant-source perspective, a tsunami generated around the Pacific could strike our shores within hours,” he said.
Knowing the signs of a possible tsunami is key. In addition to being aware of the connection between significant earthquakes and possible tsunamis, Wilson said one sign a tsunami might be coming is water receding from the coastline. He said people often run toward the water to see the rocks and catch the fish that become visible, which is contrary to the consistent advice of getting away from the coast.