Tsunami Information

A Tsunami is a series of ocean waves that are sometimes generated at the same time as an underwater earthquake. Large underwater landslides can also displace a great deal of water and generate a tsunami. A tsunami wave can race outward in all directions at speeds of up to 800 kilometres an hour and can reach heights of six to nine metres at the shoreline.

Tsunami Wave

What Should I Know About a Tsunami?

  • They have nothing to do with the tides or the weather and act differently from ordinary waves.
  • They can move through the ocean at intense speeds and be scarcely noticeable, even when passing under a boat.
  • The first wave of a tsunami is often not the largest; others may follow for a period of several hours.
  • Their danger lies in shallow waters, near shore.
  • Heights of the waves increase as the tsunami runs into river and coastal channels.

Types of Tsunami Alerts

Alert Level




Flood wave possible

Full evacuation suggested


Strong currents likely

Stay away from the shore


Danger level not yet known

Stay alert for more information


Minor waves at most

No action suggested


Tidal gauges show no wave activity

Confirm safety of local areas

How Can I Prepare Myself For a Tsunami?

  • Sign up for Saanich Peninsula Alert to ensure you receive critical alerts during an emergency. Information regarding sheltering in place or evacuation instructions would be delivered over Saanich Peninsula Alert.
  • Create emergency kits for the purpose of sheltering in place, and grab-and-go in the event of an evacuation
  • Make a plan that includes designated meeting places and emergency contacts.