Tsunamis

What is tsunami?
A tsunami is a series of waves created by a sudden, significant displacement of the ocean floor. They can be generated by an underwater earthquake or landslide. Tsunamis may cause dangerous coastal flooding with strong currents that may last for many hours.

What are my tsunami risks?
Use this map to find out what your tsunami risks are in San Francisco. The map shows the following:

  • Tsunami Inundation Zones: These are locations where dangerous coastal flooding may occur as the result of a tsunami.
  • Maximum Evacuation Zones: These zones show the maximum extent of evacuations should a tsunami occur.
  • Tsunami Evacuation Sites: Locations away from the inundations zones where evacuated residents can assemble.


How can I prepare for a tsunami?
Know the warning signs: Strong ground shaking, a loud ocean roar, or the water receding are all nature’s warnings. If you’re by the water move inland and higher ground immediately. If there is time (a distant source tsunami) we will send out alerts and instructions.

AlertSF is one way the City will send alerts. Sign up by texting your zip code to 888-777 or by visiting www.alertsf.org. The Outdoor Public Warning System (Sirens), Wireless Emergency Alerts (alerts on your mobile device), and the Emergency Alert System (alerts of television and radio) may also be used to alert residents and visitors of San Francisco about possible danger.

Prepare and plan ahead of time: Prepare yourself by gathering supplies, planning ahead, and getting connected with your community. 

  • Pack a go bag and store it somewhere quickly accessible. Your bag should have things like water, extra clothes, and first aid kit.
  • When you have to act fast, having a plan that you’ve practiced is the key. Start a plan by visiting www.sf72.org/plan.
  • Get to know your neighbors and look out for each other now. Find out who can help and who needs help in an emergency.