The recent tragic earthquakes in Japan and New Zealand have been sharp reminders of the incredible destructive power of the natural world. Many people have started to speculate how likely such earthquakes might be in Canada.
The British Columbia coast and Vancouver Island are certainly areas where major earthquakes can and have occurred. The biggest occurred on Jan. 26, 1700 and is estimated to be roughly of the same magnitude as the recent quake in Japan. Geological evidence of this huge quake can still be clearly seen more than 300 years later.
In June 1946, a major earthquake, registering 7.3 on the Richter scale, occurred west of Courtney and Campbell River on Vancouver Island. There was widespread property damage. There were two deaths attributable to the quake, one by drowning and the other by heart attack.
Canada’s largest recent earthquake (magnitude 8.1) occurred on Aug. 22, 1949 near the Haida Gwaii (Queen Charlotte Islands). Again there was widespread property damage. However, while this was a stronger quake than the one in 1946, because it was centered offshore, the damage was not as severe as the Vancouver Island earthquake.
The worst earthquake ever recorded in North America was the terrible Alaska earthquake on Good Friday, March 27, 1964. It registered 9.2 on the Richter scale. 131 people lost their lives. In Canada, more than $10 million in property damage was recorded as a result of tsunamis.
Earthquakes are generally rare in Alberta and when they do occur, they are mild. Most of the prairies are part of a large continental plate. It is only along the Rocky Mountains, in the Northwest Territories and in parts of northern Alberta and B.C. that quakes usually occur.
There was an earthquake, west of Sylvan Lake, in the early part of the last century. There were not the scientific measuring stations in those days so there does not appear to be a record of how strong the quake was. Moreover, the region was so sparsely populated that there is no record of any property damage.
Newspaper accounts of the time report that the tremor was accompanied by a loud boom, much like a very brief thunderstorm. Nevertheless, the event seems to have sparked only curiosity and not any fear or panic.
There was an earthquake measuring 5.4 on the Richter scale that occurred in April of 2001 northeast of Dawson Creek. It was felt across northern B.C. and Alberta and was noticed as far away as Edmonton. Fortunately, there was no significant damage other than a number of items being knocked off of shelves and walls.
On October 19, 1996 an earthquake, measuring 3.8, struck near Rocky Mountain House. A strong bang was heard, which woke a number of people up. Fortunately, no damage was reported, although the alarms went off at the Strachan Gas Plant.
Strachan is considered one of the real “hot spots” for earth tremors in Alberta. However, the strongest of these events have only been three on the Richter scale, about the same disruption as heavy trucks driving past a house. Usually the tremors are so mild that they are only recorded by seismic equipment and are not noticed by anyone.
In recent years, the earthquakes noticed in Alberta have occurred some distance away from the province. On Oct. 28, 1983 there was a significant earthquake in Custer County, Idaho. There was extensive property damage at the site and two deaths. In Red Deer, employees felt the Provincial Building shake and in Edmonton, the C.N. Tower swayed.
In October 1985, a series of earthquakes commenced in the Nahanni region of the Northwest Territories. The quake on Oct. 5 measured 6.6 while the one on Dec. 22, 1985, measured 6.9. There were reports that some people’s Christmas trees swayed and some houses in Northern Alberta rattled.
While no one was injured, it left a number of people feeling rather uneasy.