You're standing on the sand at Santa Monica or maybe watching the fog roll into Bodega Bay. The Pacific looks infinite, rhythmic, and—most of the time—totally chill. But there’s this nagging question that pops up every time a big quake hits the news: does California get tsunamis, or is that just a movie trope?
Honestly, the answer is a heavy yes. But it’s not exactly like the skyscraper-high walls of water you see in Hollywood blockbusters.
California has a long, documented history of getting walloped by the ocean. Since 1812, the state has seen over 80 recorded tsunamis. Most were tiny, barely moving the needle on a tide gauge, but a handful were absolute killers. We’re talking about surges that leveled city blocks and swallowed harbors whole. It’s not a matter of if the next one arrives; it's just a matter of where the earthquake starts.
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The Day the Water Didn't Stop: 1964 and Crescent City
If you want to understand the real risk, you have to look at Crescent City. This little town near the Oregon border is basically a "tsunami magnet" because of the way the underwater topography—the bathymetry—is shaped. It focuses wave energy like a magnifying glass.
Back in March 1964, a massive $M9.2$ earthquake hit Alaska. It was the second-largest quake ever recorded. While Alaskans were dealing with the immediate wreckage, a series of waves was silently barreling across the Pacific at the speed of a jetliner.
When the surges finally hit Northern California, they weren't just "waves." They were relentless surges of debris-filled water. The fourth wave was the monster. It rushed nearly two miles inland, destroying 29 city blocks. Twelve people died in that event alone. It remains the deadliest tsunami in California's modern history, and it's the reason why you see those blue "Tsunami Hazard Zone" signs all over the coast today.
Why California is Actually at Risk
So, why does this happen? Basically, California is caught in a pincer move between two different types of threats.
1. The Distant Threat (Teletsunamis)
Most of the damaging tsunamis we've seen lately come from thousands of miles away. Think Alaska, Japan, or Chile. Because the Pacific "Ring of Fire" is so active, a massive subduction zone quake anywhere in the basin can send energy our way.
- The 2011 Tohoku Tsunami: When Japan's coast was devastated, the energy traveled all the way to California. It caused over $100 million in damage to California harbors, specifically in Santa Cruz and Crescent City.
- The 2022 Tonga Eruption: Even a volcanic eruption in the South Pacific caused flooding in Santa Cruz and Ventura. It was a wake-up call that tsunamis don't always need an earthquake to start.
2. The Local Threat (The Big One)
This is the one that keeps geologists like those at the California Geological Survey up at night. While the San Andreas Fault is mostly on land (and usually moves side-to-side, which doesn't displace much water), the Cascadia Subduction Zone in the north is a different beast.
This fault runs from Vancouver Island down to Cape Mendocino. It’s a "megathrust" fault, meaning one plate is sliding under another. When it snaps—which it last did in 1700—it can produce a tsunami that hits the Northern California coast in minutes, not hours. You won't get a text alert in time for that one. The shaking is your warning.
What Most People Get Wrong About Tsunami Waves
Most people think a tsunami is one big wave that breaks like a surfer's dream. Nope. Not even close.
Think of it more like a tide that refuses to stop coming in. It’s a massive "wall" of water that keeps pushing and pushing for ten or twenty minutes straight. And it’s almost never just one wave. Usually, the second or third surge is the biggest. In 1964, people went back to their homes after the first wave, thinking the danger had passed. That’s when the fourth wave caught them.
There's also the "drawback" myth. You've probably heard that the ocean disappears right before a tsunami hits. While that can happen if the trough of the wave hits first, it doesn't always happen. Sometimes the first sign is just a rapid rise in water level. If you see the ocean receding unnaturally far, exposing fish and reefs that are usually underwater? Run. Don't grab your phone for a TikTok. Just move.
Real-World Damage Beyond the Beach
It’s not just about houses on the sand. The economic hit is wild. California’s ports—like Los Angeles and Long Beach—are the lifeblood of the U.S. economy. Even a "small" three-foot tsunami can create crazy currents in narrow harbor channels. These currents can snap mooring lines like they’re pieces of string, turning multi-million dollar cargo ships into floating battering rams.
In the 2011 event, the currents in Santa Cruz Harbor were so strong they literally sank several boats and demolished the docks. The water was swirling in huge vortices, basically turning the marina into a giant washing machine full of fiberglass and wood.
Survival is Actually Pretty Simple (If You're Fast)
If you live in or are visiting a coastal area, you’ve gotta know the drill. It’s not about being paranoid; it’s about being realistic.
- Feel the ground shake? If you're near the beach and the earthquake lasts more than 20 seconds, don't wait for a siren. The shaking is the siren. Move inland or to high ground immediately.
- Know your zone. Check the California Tsunami Hazard Area Maps. Most cities have very specific evacuation routes.
- High ground doesn't have to be a mountain. Sometimes, getting to the third floor of a sturdy, reinforced concrete building is enough if you can't get inland fast enough. This is called "vertical evacuation."
- Stay away for hours. Tsunamis are a "series" of waves. The danger often lasts for 12 to 24 hours after the first surge.
Actionable Steps for Your Next Beach Trip
Before you head out to catch some rays, take two minutes to look at the "Tsunami Hazard Zone" signs at the entrance to the beach. They aren't there for decoration.
Look for the nearest hill or the tallest, most solid-looking building. If you're staying in an Airbnb in a low-lying area like Newport Beach or the Silver Strand in San Diego, have a "go-bag" by the door. It sounds "prepper-ish," sure, but in a real-deal local tsunami, you might only have 10 to 15 minutes to move.
California is a beautiful place to live, but it’s a geologically active one. Respecting the power of the Pacific means knowing that occasionally, the ocean decides to come ashore. Stay informed, know your exit, and you'll be fine.
Next Steps for You:
- Visit the MyHazards tool by Cal OES to type in your specific address and see your risk level.
- Sign up for Wireless Emergency Alerts (WEA) on your phone to ensure you get distant tsunami warnings from the National Weather Service.
- Check your local county’s emergency management website for specific "Tsunami Playbooks" that detail harbor and street-level evacuation plans.