Wave of information missing after B.C. tsunami
- November 2, 2012 12:31 PM |
- By Quirks
By Bob McDonald, Quirks & Quarks
Now that the ground has settled down on the West Coast, we can look back on how people were informed about what to do when disaster strikes.
On the East Coast, New Yorkers knew that hurricane Sandy was coming and had time to prepare; but people on Haida Gwaii were taken completely by surprise by the earthquake.
I happened to be sitting on a couch on Quadra Island, about 350 km south of the epicenter, when the earthquake first appeared as a sudden, strange dizzy feeling in my head, followed by the sight of lamps swinging from the ceiling. There was no rumble or violent shaking of the ground. A swinging chandelier in a neighbouring building confirmed that a significant tremor had just passed through.
Fortunately, the power remained on, so we could turn on the radio, television and computer for information.
At first, that information simply wasn't there. How big was the quake, where was the epicenter, and most importantly, did it generate a tsunami?
The computer came through first with blogs and tweets about a quake, just off the coast of Haida Gwaii - what used to be called the Queen Charlotte Islands.
If there was a tsunami, it could strike the local coastal communities in a matter of minutes. Unlike regular waves, tsunamis can move at hundreds of kilometers per hour through the ocean. Visions of the enormous fast-moving wave that washed over towns and farm fields in Japan flashed through my mind.
Our cabin was positioned on a hill, high enough above the sea to be safe from rising waters. But family and friends in the beach town of Tofino, on the west coast of Vancouver Island, were at much higher risk. We began texting right away.
Fortunately, news spreads fast among young people who are so dialed in to each other. Yes, they heard there was a quake but didn't know much more. They were moving to higher ground anyway.
As the minutes passed by, a news reporter on television mentioned the quake, almost in passing, at the end of the program and said they'd have more later. Still nothing on the radio.
One of the blogs said the quake was reported by the U.S. Geological Survey, so I went to their website and there it was: a magnitude 7.7 strike-slip earthquake. A tsunami warning had been issued for North Vancouver Island to Alaska, but no actual wave had been reported. (Emergency officials in B.C. did not issue any sort of tsunami alert or advisory for another 39 minutes.)
A strike-slip quake is when the two sides of a fault slide past one another, which does not usually generate a tsunami. It takes a thrust fault, where the pieces move up and down, to really disturb the water.
I was thankful I knew that, which provided some relief, although the tsunami in Indonesia was caused by the collapse of an underwater cliff that was triggered by a quake. There are very large cliffs off the Continental Shelf, all along the West Coast. Could that happen here?
Even though Tofino wasn't in the tsunami warning area, officials took the safe route and sounded the newly installed sirens that line the beaches. Some residents thought it was noise from a nearby party. Others knew what the sirens meant, but weren't sure which way to go for the evacuation. Some tourists in beach hotels were given wrong information. It was the sight of traffic on the single main road, all moving in one direction, that pointed the way to the highest spot in town.
In Hadia Gwaii, both power and cellphone service went down, so people used word-of-mouth and instinct to move to higher ground. Nature had already given them a powerful direct message.
Almost an hour after the event, a live television special began with some conflicting information about the size of the earthquake and its exact location.
Almost two hours after the event, there were no reports of damage, suggesting no tsunami, but information was still sketchy. Again, it was the U.S. Geological Survey site that first announced the downgrade of the warning to an advisory. The threat of a damaging wave was now much less. We text that info to family in Tofino, who are finally on high ground and they spread the word to other residents, who relax a little.
I never thought that I would become a source of information following an earthquake, but that's how desperate people were. It underlies the importance of accurate info when an emergency arises.
The second lesson that came out of the experience is the importance of information available ahead of time, a plan of action for what to do when the next one happens.
Now everyone in the region is asking themselves, "Do we have an emergency survival kit with flashlight, water, food and blankets? Do we know the evacuation route to higher ground? Does our area have an emergency broadcast system that will break into regular programming with the latest information?"
Even though this was the second-largest recorded earthquake to hit B.C., no one was hurt and there was no damage to property. But had the same quake struck a little farther south, where thrust faults move with up and down motion, there likely would have been a tsunami that would have struck the more populated areas of Victoria, Vancouver and Seattle.
The entire west coast of North America is a boundary between two of the Earth's tectonic plates that are constantly in motion, which means there will always be earthquakes in that area. That's the foreknowledge for people who choose to live there. Now, we need to do a better job of filling in the information needed for what people need to do immediately after the next Big One strikes ... and trust me, it will.
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