What is a Tsunami?
A tsunami is a series of destructive ocean waves following an earthquake, landslide or volcanic eruption. They do NOT appear as a normal wave but may appear as a rapidly rising or falling tide that can last for hours, reaching up to a mile inland. Besides deadly flooding, tsunamis can also create dangerous undercurrents in coastal waters.
San Francisco State University Main Campus would most likely NOT need to evacuate in the case of a tsunami impacting San Francisco Bay Area but the Estuary and Ocean Science Center in Tiburon most likely WOULD evacuate.
Remember that tsunami alerts may be updated or canceled as more information becomes
available. Continue to monitor emergency information. (https://www.tsunami.gov/)
If You are Near a Coast and a Tsunami Alert is Issued:
- Move to higher ground immediately. If you feel strong shaking, do not wait for an official alert. A local strong earthquake can cause a tsunami to arrive within 10 to 15 minutes. - "Long or Strong, Get Gone"
- Go 100 feet up or at least a mile inland to be completely out of the hazard zone.
- Do NOT go to the shore to watch. Tsunamis move faster than you can run.
- Stay away from beaches, harbors and marinas.
- Only return to hazard areas after an official all-clear has been received. Tsunamis can hit land up to 8 hours after an initial earthquake, and the first waves are NOT the largest.
- Follow instructions from local officials and emergency alerts.
Confused by what they all mean? Here is a quick guide on what to do for each type.
| Alert | Meaning | Action |
| Tsunami Information Statement | An earthquake has occurred but there is no threat, OR it was very far away and a threat has not been identified. |
Monitor local emergency information. |
| Tsunami Watch |
A distant earthquake has occurred and a tsunami might be coming, but there is still uncertainty while they collect more information. |
Be aware. Monitor local emergency information. Know your evacuation route if in a hazard zone and be prepared to take action. |
| Tsunami Advisory |
A tsunami with a potential for dangerous currents or waves is expected or occurring. Conditions are dangerous for swimmers, boaters and those near the water. |
Take Action. Stay out of the water and away from beaches and waterways. Follow instructions from local officials. |
| Tsunami Warning |
The most serious alert. A tsunami that can cause widespread flooding and dangerous currents is expected or has already arrived. Conditions may continue for several hours or days after. |
Danger-Take Immediate Action. Must evacuate coastal zones and move to high ground or inland. |
Sources
1. American Red Cross Tsunami Preparedness Checklist
2. https://www.khon2.com/local-news/whats-the-difference-between-tsunami-warning-watc
h/
3. https://www.tsunami.gov/?page=message_definitions
4. https://www.weather.gov/safety/tsunami-alerts
5. https://www.conservation.ca.gov/cgs/Documents/Tsunami/How-to-Survive-a-Tsunami