The California tsunami danger is real. The 7.0 earthquake is wake-up call to prepare

A boat motors through tsunami surge at the mouth of the Santa Cruz Small Craft Harbor on Jan. 15, 2022.

(Shmuel Thaler / Santa Cruz Sentinel)

By Grace Toohey

and Karen Garcia

Dec. 6, 2024 3 AM PT

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Fear, anxiety, and confusion hit the West Coast early Thursday. A rare tsunami warning was issued for Northern California and southern Oregon. This followed a magnitude 7 earthquake 55 miles off Eureka’s shore.

Evacuations were ordered, and sirens sounded. The Bay Area’s commuter rail service was suspended through its underwater Transbay Tube.

But in about an hour, the warning was canceled. Though the conditions were right, no major tsunami formed — this time.

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“It could have moved a lot of water,” said Dave Snider, the tsunami warning coordinator at the National Tsunami Warning Center in Alaska. “We’re glad it didn’t.”

The conditions could have produced a dangerous tsunami, but predicting such an event is hard. Snider said his team is cautious, especially when the earthquake hits close to the coast.

“We’re completely reactionary to the earthquake event,” Snider said. “Time has to be respected to get people safe.”

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Tsunami warnings are rare for the West Coast, and major tsunamis are even rarer, Snider said. But they do happen, making it crucial for residents to prepare and know how to respond.

He said Thursday’s incident was a good reason to “refresh what it means to live in tsunami country.”

A brief history of tsunamis in California

Here is what we know about past tsunamis in California, from Times reporting and state records:

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The last time the U.S. West Coast saw a tsunami advisory was in January 2022, Snider said, after an underwater volcano erupted in the South Pacific. This caused a powerful tsunami.

California experienced relatively minor effects. But at Santa Cruz Harbor, waves flooded streets and a parking lot. Cars floated like toy boats. Water poured into bathrooms and electrical transformers onshore. It caused an estimated $6 million in damage to Santa Cruz alone, officials later said.

In 2011, a tsunami from Japan’s earthquake hit California’s coast, causing over $100 million in damage. This damage was at marinas and harbors, state officials estimate. In Crescent City, many boats were destroyed, and docks were badly damaged.

One person died while taking pictures of the tsunami, reportedly swept into the sea.

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Crescent City has seen two tsunamis recently. In 2006, a tsunami warning expired, but a significant surge still damaged the harbor. This was hours after the warning.

The 1964 Alaskan earthquake caused a devastating tsunami in Crescent City. It destroyed 29 city blocks and killed 11 people. The waves also destroyed or damaged 91 houses and 172 businesses.

California has records of tsunamis in 1960 and 1946, each killing at least one person. The 1946 tsunami, from an Alaska earthquake, flooded Half Moon Bay.

One of the earliest tsunami records in California is from 1812. A Santa Barbara earthquake triggered a tsunami that destroyed coastal villages and ships. According to the U.S. Geological Survey.

The 1700 mega-tsunami was from a magnitude 9 earthquake on the Cascadia fault system. This fault runs 700 miles from Northern California to Vancouver Island.

This earthquake was so strong that parts of the Pacific coastline dropped by up to 5 feet. Native American stories tell of how the prairie became ocean and canoes were flung into trees.


Imagine if a massive earthquake hit today. Scientists warn of a huge tsunami that could destroy coastal towns and damage U.S. 101. This disaster could cost $70 billion and affect a wide area of the Pacific Coast.

More than 100 bridges and power lines would be lost. Coastal towns would be cut off. People would have just 15 minutes to move to higher ground.

As many as 10,000 could lose their lives, according to a study from over a decade ago.

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Can you prepare for a tsunami?

Snider said these rare events are hard to predict. But, there are ways to prepare and understand what might trigger them.

Look for natural warning signs. Feeling a strong or long earthquake is one. If you’re by the beach and see the ocean rise or fall suddenly, or hear a loud roar, it’s time to go inland.

“If you are on the beach or in a harbor and feel an earthquake, immediately move inland or go to high ground. If strong shaking lasts for 20 seconds or more, everyone within the tsunami evacuation area should evacuate as soon as it is safe to do so,” the California Geological Survey advises.

Know if you live or visit a tsunami evacuation zone. The California Geological Survey has online maps of tsunami hazard areas across the state. In Southern California, this includes Ventura, Oxnard, Malibu, Venice, and more.

In the San Francisco Bay Area, vulnerable spots include parts of San Francisco and the Embarcadero. This affects a big part of the Financial District and South-of-Market areas.

Find tsunami hazard maps in your area. If you can’t find them, state officials suggest getting 100 feet above sea level or two miles inland. “If you cannot get this far, go as high as possible. Every foot inland or upwards can make a difference,” state officials say.

The National Weather Service operates two tsunami warning centers. They aim to monitor for tsunamis and the earthquakes that may cause them, to send tsunami alerts. To get official notifications, sign up for text message alerts from your local government, get a battery-powered NOAA weather radio, or listen for TV, radio, or automated telephone announcements.

Sign up for alerts here:

• The National Weather Service Tsunami Warning System
• The National Oceanic and Atmospheric Administration Weather Radio
• NOAA Wireless Emergency Alerts
• Local emergency alerts (scroll to the bottom of the page)

How should you respond after a tsunami warning?

Evacuate the area by foot and get to higher ground. Don’t get in your car and try to drive away from the hazardous area — evacuating by car could create a traffic jam.

If you feel the earthquake: Drop to the floor, take cover and hold on until the shaking stops.

If you evacuated from a coastal area, stay away until officials permit you to return. Do not go toward the coast to watch a tsunami. Tsunamis move faster than a person can run.

Don’t let your guard down after the first tsunami wave. The first one usually is not the highest one. Large tsunami waves might be more than 50 feet high in some areas close to the coast. Tsunami waves can last for hours.

Do not attempt to surf or watch a tsunami. You cannot surf a tsunami, as there is no face to a tsunami wave. Regular waves flow in a circle without flooding higher areas. Tsunami waves are unpredictable and flood the land like a wall of water.