Tsunami Preparedness 101 - What You Need to Know
April 9, 2019
This week is Tsunami Preparedness Week (Sunday, April 7 – Saturday, 13, 2019).
Although tsunamis are rare, it’s important to understand the impact of a tsunami on Victoria and what to do in the event of a tsunami warning.
What is a tsunami?
A tsunami is a natural hazard, consisting of a series of long, surge-like waves that are usually caused by an underwater earthquake, landslide, or volcanic eruption.
Is Victoria at risk of a tsunami?
The City of Victoria is not at risk like coastal communities such as Tofino and Ucluelet, which are on the open water and have notification sirens. Victoria does not expect a large, fast “wave” like we’ve seen in places like Thailand and Japan.
The main tsunami threat to Victoria is from a Cascadia Subduction Zone earthquake off the Pacific Coast of Vancouver Island.
Tsunami modelling has been completed for our region for the most likely and highest impact scenario, which is a 9.0 magnitude Cascadia Subduction Zone earthquake. An earthquake that happens far away that we don’t feel, may cause a very low-risk and low-impact tsunami event in Victoria.
The shaking from an earthquake is your warning of a local tsunami. The projected arrival for a local tsunami at Victoria’s harbour is 76 minutes, with a maximum water level of 2.5 metres (8.2 feet). This estimate is based on a 9.0 Cascadia Subduction Zone earthquake. (In contrast, the 2011 Japanese tsunami caused by a 9.0 earthquake had a maximum water level of 40 metres or approximately 131 feet.)
(Tsunami graphic at right courtesy of Prepared BC)
Where will you be safe from a tsunami?
You are safe from a tsunami in the Capital Region if you are located four metres (13 feet) above sea level.
TIP: Check the compass on your mobile device or Google Earth to find out your approximate elevation.
Victoria's Tsunami Hazard Map
It’s important to know if you are located in a tsunami hazard zone so that you can move to a safe area in the event of a tsunami warning. To see if you live, work or play in a tsunami hazard zone, view the City of Victoria’s interactive Tsunami Hazard Map.
What to do in a Tsunami Warning?
In the event of a tsunami warning, move to higher ground immediately (on foot or bike if possible) if you are in a low coastal area, beach, marina or harbour, and take your emergency kit with you. Do not stay to watch the tsunami waves and do not return until officials say it’s safe to do so. Depending on your location, higher ground may only be a few blocks away.
If you are not located in a tsunami hazard zone, shelter in place and be prepared to assist family, friends and neighbours in need of shelter. Stay tuned to local media channels for updates.
How will you be notified of a Tsunami Warning?
If you are near the ocean and feel an earthquake that makes it difficult to stand for 60 seconds or more, Drop, Cover, and Hold On, count to 60 once all shaking has stopped, and then move to higher ground or inland immediately. Do not wait for an official tsunami warning.
The City of Victoria receives notifications of potential distant tsunamis from the National Tsunami Warning Centre (NTWC). Vic-Alert, the City’s subscriber-based emergency notification service and the provincial government’s AlertBC system, both send out distant tsunami warnings.
The City of Victoria has the resources in place to issue tsunami warnings without a siren due to the lower risk, the slow water level rise, and the length of warning time we will receive after an earthquake has occurred. Our emergency responders have the capacity to go door-to-door and use loud speakers to the small areas within the City of Victoria that the tsunami modelling has shown the water level will rise to.
- For the latest information on an earthquake or tsunami in BC, follow Emergency Management BC on Twitter @EmergencyInfoBC for emergency alerts and updates.
- In the event of a tsunami notification, information will be posted here on the homepage, on Facebook, and on Twitter at @CityofVictoria.
- Sign up for Vic-Alert, the City of Victoria's new emergency notification service. Receive alerts and updates by text, phone or email on emergencies that may impact you.