Look on bright side

Some facts suggest that this choice is available regarding the “Big One” which will arrive here one day.

Optimism is always better than pessimism.

Some facts suggest that this choice is available regarding the “Big One” which will arrive here one day.

Huge earthquakes like the 1960 magnitude 9.5 one in Chile, or the 9.2  1964 quake in Alaska, tend to cause the greatest destruction, but size is not the only factor. For example, the California 7.1 Candlestick Park quake in 1989 killed or injured about 400 people and damaged or destroyed the same number of homes.

Here in B.C., quakes over magnitude seven occur roughly every 12 years, including the 7.7 one at Haida Gwaii last November, and the biggest one of 8.1 on the Charlotte fault in 1949.

The damage caused by all these quakes has been negligible, and there is a reason for this.

Western California is composed of young, relatively unconsolidated rocks, which tend to fail under stress.

British Columbia, in contrast, is underlain by hard igneous and metamorphic rocks, with a lesser amount of indurated sedimentary ones. These rocks are all more resistant to stress.

Seismic waves can be roughly compared to ocean swells, which may move a boat up and down without damage.

If the swells turn to waves, and the rocks break up, the situation becomes much more serious.

All things are relative, and a really huge earthquake could be destructive here. Let’s be optimistic and hope that it will only result in bigger swells.

James M. Drummond

Qualicum Beach