Probably the question I am asked most frequently after an earthquake occurs that affects the Alberni Valley is "why didn't I hear the sirens?".
Our tsunami warning system will only be activated when we are placed under a tsunami warning.  This will be initiated by the West Coast and Alaska Tsunami Warning Centre in Palmer, Alaska.  This department of NOAA is responsible for helping to protect life and property from tsunami hazard by providing tsunami information and warning messages to several areas including Canada and the US states except for Hawaii.
A tsunami warning is issued when a tsunami is generated with the potential to cause flooding of more than one metre above the normal high tide mark.  Tsunami warnings are disseminated within five minutes of an earthquake and are initially based on seismic information alone.  After wave action is recorded on sea gauges close to the event, the warning may be cancelled, restricted, expanded or downgraded to an advisory.  Also at this time depending on the location of the earthquake, wave height and time of arrival may be accurately predicted.
When a tsunami warning is issued for the Alberni Valley as a result of a distant earthquake, the sirens of the tsunami warning system will be activated and a voice message will follow with instructions to evacuate low lying areas.  If we feel an earthquake that causes ground shaking, objects to fall off shelves, difficulty walking normally and lasts more than 20 seconds, that will be our warning to immediately head to higher ground without waiting to hear the sirens.
Residents of Port Alberni who live or work in low lying areas should be aware of the inunation zone and evacuation routes.  Maps showing these areas are available on the Alberni Clayoquot Regional District website (acrd.bc.ca), at community facilities and events, and by giving me a call.  Taking some time now to become familiar with which evacuation route you will use in an emergency will ensure that your response to a tsunami warning will be quick and calm.
For more information on tsunami warnings and other emergency preparedness topics please email me at [email protected] or laurie_l'[email protected] .