State authorities’ tsunami inundation zone includes much of Downtown Santa Cruz and spans several blocks inland near Pleasure Point, Arana Gulch, Schwan Lagoon, Soquel Creek and other areas. In some areas with coastal bluffs, only beaches would likely be affected. The exact extent of flooding would depend on the distance and strength of the earthquake that triggers the waves.

People who live in a tsunami hazard zone should identify a place to evacuate at least 300 feet above sea level or at least 1 mile inland, according to the American Red Cross.

A 2009 map shows a tsunami inundation line in red that represents the “maximum considered tsunami runup from a number of extreme, yet realistic, tsunami sources,” according to state authorities. (California Emergency Management Agency)

A 2009 map shows a tsunami inundation line in Santa Cruz. (California Emergency Management Agency)

What to do in an earthquake or tsunami

Residents in a tsunami hazard zone might feel an earthquake, hear a loud roar from the ocean, or see unusually fast rising or draining of water — which could all be indicators of an approaching tsunami, according to state authorities. 

• In an earthquake, protect yourself by dropping to the ground, covering, and holding on. Be prepared for aftershocks.
• If you are on the beach or near water and feel an earthquake, move quickly inland to higher ground as soon as you can move safely. Do not wait for an official warning or instructions from officials.
• If you are in a tsunami hazard zone and receive an official warning, stay out of the water and away from beaches and waterways. Evacuate to higher ground.
• Quake damage can include fallen power lines and weakened buildings that should be avoided. 
• Seek official information online and from radio and TV. 

Alerts Thursday 

After a 7.0 earthquake shook the coast of Humboldt County at 10:44 a.m. Thursday, the National Weather Service at 10:49 a.m. issued a tsunami warning and sent a phone alert for people from the southern Oregon Coast to Davenport. It urged people to avoid the coast and seek high ground.

A preliminary forecast predicted that a tsunami was possible, and could reach San Francisco by 12:10 p.m. 

County staff deployed sheriff’s deputies to evacuate beaches near Davenport, but soon recalled them.

• At 11:16 a.m., Capitola Police sent a Nixle alert to subscribers that stated that there was a tsunami warning “until further notice.” A second text said Capitola was not in the warning zone, and a cancellation text came at 12:15 p.m.
• At 11:20 a.m., UCSC’s SlugSafe system sent a text that stated that UCSC was outside the tsunami warning zone. It also included information about what to do in a tsunami.
• County of Santa Cruz staff waited to consult with the National Weather Service before sending their own CruzAware alerts by text message, email and phone to registered users.  By the time the county warnings were sent about 12 p.m., the National Weather Service warning had been lifted minutes earlier. Cancellation notices followed. 

Santa Cruz County’s CruzAware warning included the entire coast of the county “out of an abundance of caution,” said Dave Reid, director of the Santa Cruz County Office of Response, Recovery and Resilience.

Geologists can detect earthquakes nearly instantaneously, but it takes longer to determine exactly how powerful they are, Kennedy said. As geologists learned more about the earthquake, they determined it wouldn’t cause a tsunami, she said.

Recent tsunami damage

In March 2011, a tsunami caused $22 million in damage at the Santa Cruz Small Craft Harbor. A 9.0 magnitude quake in Japan sent waves that funneled into the harbor and concentrated their force, crushing boat docks and sending vessels and equipment into a soup of surging water. 

The quality of emergency information also varied widely across media and informal networks. A Spanish language radio station told people to flee miles inland for fear of huge waves that never materialized. A group gathered near Summit Road and Highway 17. 

Authorities advised people to stay away from beaches and coastal areas, but more than 100 people flocked to the Murray Street bridge to watch the harbor damage.

Emergency resources

• Residents can sign up for the County of Santa Cruz’s CruzAware alerts by phone, email or text. The site also includes signups for other emergency systems. 
• Police in Santa Cruz, Capitola, Watsonville and Scotts Valley and some fire departments send Nixle text alerts to registrants during emergencies.
• UC Santa Cruz students, faculty and staff can receive emergency alerts from campus officials in its SlugSafe system.
• Tsunami inundation maps for Davenport Santa Cruz Live Oak and Capitola Watsonville are available from the California Emergency Management Agency.
• Maps of tsunami hazard zones for coastal California are available from the California Department of Conservation.

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