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When an 8.8-magnitude earthquake struck Russia’s remote Far East, it set off a chain reaction across the Pacific. Tsunami alerts went out to cities like Los Angeles, San Diego, and San Francisco. In Japan, nearly 2 million people were told to evacuate.
The waves followed, reaching Hawaii, California, and parts of Washington.
It was one of the strongest earthquakes ever recorded and though early reports show little damage, the event serves as a powerful reminder: Tsunami risk isn’t just theoretical.
And now, as advisories lift and life returns to normal, coastal homeowners are left wondering: Could this happen where I live, and would my home survive it?
Where are tsunamis a real risk to homes in the U.S.?
Tsunamis are rare, but when they strike, the consequences can be catastrophic, especially for coastal communities. Tsunamis that cause damage or fatalities near the source (such as an earthquake or landslide) occur about twice a year, according to the Global Historical Tsunami Database. The more distant events—those that cause destruction more than 620 miles from the epicenter—are much less frequent, averaging about twice per decade.
One of the most dangerous and well-known tsunami threats in the U.S. lies in the Pacific Northwest, which sits atop the Cascadia Subduction Zone. Here, the Juan de Fuca oceanic plate is slowly being forced beneath the North American continental plate in a geological standoff that has the potential to trigger an earthquake that’s been dubbed “The Really Big One.”
When that massive earthquake—which scientists anticipate will be somewhere between 8.7 and 9.2 on the Richter scale—eventually hits, the coastline could drop by as much as six feet, unleashing a tsunami capable of traveling across the Pacific and flooding low-lying areas from Northern California to Japan.
Recent studies suggest that tsunami flood risk from this specific event may be severely underestimated in parts of the Pacific Northwest. Maps used for emergency planning don’t fully capture how much land could be inundated, especially if subsidence lowers the elevation further.
Outside of this high-risk zone, other parts of the U.S. are still vulnerable. Hawaii, Alaska, the U.S. West Coast have all experienced tsunamis triggered by earthquakes from as far away as Japan, Chile, and the Aleutian Islands, as waves can race across the ocean at speeds of up to 500 miles per hour.
While the East and Gulf Coasts of the U.S. are generally less vulnerable to tsunamis due to limited tectonic activity in the Atlantic, they’re not entirely immune. Tsunami waves have reached these shores in the past, but such events have been far less frequent and less severe compared to those experienced along the West Coast.
Whether the threat is local or distant, the takeaway is the same: Coastal homeowners need to understand their exposure—and prepare accordingly.
What puts a home at greater risk?
Tsunamis vary widely in speed, height, and force making risk difficult to assess and understand for homeowners. But one factor is consistent: If your home is located in a tsunami inundation zone, it’s at risk. These zones represent areas likely to be flooded in the event of a tsunami, and they are typically mapped by state emergency agencies and the National Tsunami Hazard Mitigation Program.
Structural vulnerability is another key factor. Homes with shallow or unreinforced foundations are especially prone to severe damage, as tsunami waves often carry fast-moving water filled with salt, sediment, and heavy debris. Even well-built homes can be at risk if they aren’t properly anchored or elevated—entire structures can be shifted off their foundations by the force of incoming waves.
To evaluate your home’s tsunami resilience, the Federal Alliance for Safe Homes recommends consulting a licensed structural engineer. An expert can identify weak points and suggest reinforcement measures, such as:
- Strengthening foundation anchoring and wall bracing
- Raising mechanical systems above expected flood levels
- Using natural barriers—like vegetation or berms—to help reduce wave energy before it reaches the home
While no home can be made tsunami-proof, taking these steps can significantly reduce the risk of catastrophic damage.
Does homeowners insurance cover tsunami damage?
In most cases, standard homeowners insurance does not cover tsunami damage. That’s because tsunamis are classified as flood events, which are excluded from the majority of home insurance policies.
If you’re in an inundation zone, you’ll need to purchase a separate flood insurance policy, either through the National Flood Insurance Program (NFIP) or a private insurer. Most flood insurance premiums cost less than $2,000 per year, according to FEMA. Though, the price can vary based on your home’s location, elevation, and flood zone designation.
It’s worth noting that flood insurance coverage through the NFIP is capped—with a maximum of $250,000 for the structure and $100,000 for contents—so higher-value homes may need to purchase additional supplemental coverage from private providers.
With rising sea levels, more frequent major flooding events, flood insurance availability and affordability have become growing concerns in many parts of the country. That makes it all the more important for homeowners to assess their coverage options before disaster strikes.