If the Ocean Pulls Back, Do Not Film It
A tsunami announces itself in three ways, and any one of them is enough to act on. The instinct to go closer and record it is the one that kills people.
Quick answer. The three natural warnings are strong or long shaking, a sudden rise or fall of the ocean, and a loud roar from the sea. Any single one is enough. Move inland or to higher ground immediately — a nearby tsunami can arrive before a phone alert or siren.
Sign one — strong or long shaking
If you are near the coast and an earthquake is strong enough to make standing difficult, or simply goes on for a long time, prepare to evacuate the moment the shaking stops. Duration matters as much as violence here; long shaking is characteristic of the large offshore earthquakes that displace water.
Sign two — the ocean changes suddenly
A rapid rise or fall of the water is a natural warning. The sea may pull back and expose the sea floor, or surge unusually high. The withdrawal is the famous one, and it is the one that draws people onto the exposed sand with a phone out.
Sign three — a loud roar
An unusual roar from the ocean, unlike normal surf, is the third warning. You do not need to confirm it against the other two. Any one sign is enough to act.
The alert may come second
A tsunami generated close to shore can arrive before any official alert reaches your phone. Follow the natural warnings first, then official instructions as they become available. Waiting for confirmation is how the warning time gets spent.
How to leave
Use the posted evacuation route. Go on foot or by bicycle where local plans recommend it and roads are likely to gridlock. Help children and anyone who needs assistance — decide who does that before the day it matters.
What not to do
Do not go closer to watch. Stay away from beaches, waterways, harbours and bridge viewpoints. Dangerous currents can exist even when the first wave looks small, and harbours concentrate them.
The first wave may not be the biggest
Tsunami waves and currents can continue for hours, and a later wave may exceed the first. Do not return after one wave, and do not read calm water as an all-clear.
Wait for official clearance
Return only after local authorities say the area is safe. A cancelled warning in one region does not automatically clear another coastline — the all-clear is specific to where it was issued.
| Do | Avoid |
|---|---|
| Act on any single natural warning | Waiting to confirm it against the others |
| Move inland or uphill immediately | Waiting for a siren or phone alert |
| Use the posted route, on foot if advised | Driving into predictable gridlock |
| Stay away from harbours and waterways | Going closer to film it |
| Assume more waves are coming | Returning after the first one |
| Wait for your area’s all-clear | Relying on another region’s cancellation |
Sources
- NOAA — Tsunami alerts
- NOAA — Natural tsunami warnings
- Ready.gov — Tsunamis
- NOAA Tsunami Warning Center — FAQ
This guide restates official preparedness guidance. It is not medical, structural, or emergency advice for your specific situation — follow the instructions of local authorities during an actual event.