May 24, 2022

UPDATED 3:00PM – ADVISORY ENDED

FINAL UPDATE

After nearly a full day of tsunami activity the advisory has now been lifted as the wave actions and currents have subsided.

There have been a number of sensors that have captured effects from the volcanic eruption.

First, the Sea Level gauges around Vancouver Island. (You can see the video from Somass River further down this post).

You can see the gauges here. The arrow is 8:30AM this morning when we observed the unusual currents in the Somass River.

Here is the same time period for the Winter Harbour station.

Very interesting that the Winter Harbour station had obvious waves moving through but it was not nearly as noticeable in Port Alberni harbour.

Below are the gauges at Bamfield and Tofino. Smaller and more numerous perturbations.

Pressure wave also recorded on weather stations

Perhaps even more impressive is that the pressure wave from the shock of the blast was registered on stations all over the Pacific Ocean including here at Alberniweather and on Vancouver Island. This pressure wave would have been moving at around the speed of sound. It arrived about 8hrs after the blast, around 4:25AM.

The 5 minute measurements were 102.80kPa at 4:25AM to 102.89kPa at 4:30AM. A difference of 0.09kPa (0.9mb). Normally, the barometric measurements only move in just 0.01kPa or 0.02kPa movements.

I do wonder if it would have been enough to hear the pressure wave in a very quiet environment.

Here’s the same pressure signal at Alberni Elementary and Vancouver Island University in Nanaimo.

10:00AM Update

We went down to Victoria Quay to see if we could detect any strange behaviour in the river currents and weren’t disappointed. The first video below (with the mink) shows when the current switched. It had been running out (in the second video) toward the sea five minutes before.

The Tsunami Advisory will be in effect for much of the day and strange currents could persist for the next few hours. Many other locations on the West Coast of North America are experiencing the same.

7:30AM Update

EMBC Just issued this statement:

New statement in Tsunami Advisory #6 says:

 * Sea level fluctuations are beginning in Alaska and California

From Port Alberni Fire:

As a reminder only, here is the inundation zone map. No evacuation has been ordered at this time. The Tsunami sirens will be sounded only if an evacuation is ordered. If they sound you should evacuate the shaded areas. People outside of the shaded areas would not need to take action.

At this point I would expect the most likely impact to see the current of the Somass River river reversed or slowed (depending on the flow at the moment) and possibly some unusual movement in the harbour.

Original Post

You’ve probably already seen the pictures. They’re incredible! Truly a planetary-wide event has occurred in the South Pacific. This was at 5:20PM local time in Tonga.

Tsunami activity expected across the Pacific

The Explosion caused Tsunami waves locally and is expected to cause “activity” all over the Pacific basin incudling British Columbia starting around 8AM PST. Here is the highlighted BC portion of the current Advisory issued at 6:32AM.

Port Alberni and the Somass River are likely to feel the effects from this. See below for what to expect and when.

Tsunami Advisory in Effect for;

 * BRITISH COLUMBIA, The north coast and Haida Gwaii, the
   central coast and northeast Vancouver Island, the outer
   west coast of Vancouver Island, the Juan de Fuca Strait
   coast
 * British Columbia
Langara          0830  PST Jan 15
Tofino           0850  PST Jan 15


IMPACTS
-------
Impacts will vary at different locations in the advisory
areas.

If you are in a tsunami advisory area;

 * A tsunami with strong waves and currents is possible.

 * Waves and currents can drown or injure people who are
   in the water.

 * Currents at beaches and in harbors, marinas,
   bays, and inlets may be especially dangerous.

 * Some impacts may continue for many hours to days after
   arrival of the first wave.

 * The first wave may not be the largest so later waves may
   be larger.

 * Each wave may last 5 to 45 minutes as a wave encroaches
   and recedes.

 * Coasts facing all directions are threatened because the
   waves can wrap around islands and headlands and into bays.

 * Strong shaking or rolling of the ground indicates an
   earthquake has occurred and a tsunami may be imminent.

 * A rapidly receding or receded shoreline, unusual waves and
   sounds, and strong currents are signs of a tsunami.

 * The tsunami may appear as water moving rapidly out to sea,
   a gentle rising tide like flood with no breaking wave,
   as a series of breaking waves, or a frothy wall of water.

Stay safe. Don’t enter the water this morning as the currents from the Tsunami could last quite a long time. The eruption was heard in Christchurch, New Zealand nearly 2400km away! Incredible power!