TYPES OF HAZARDS
A large earthquake located close to a Canadian city could cause tens of billions of dollars damage. Potentially catastrophic earthquakes of magnitude 7 occur, on average, once every 30 years on the West Coast. The most recent of these quakes, in February 2001, caused about US $1 billion damage in Washington State. This damage, however, pales in comparison to that of the earthquakes at Northridge, California (January 1994, magnitude 6.4), and Kobe, Japan (January 1995, magnitude 7.1), which amounted to US $20 billion and US $147 billion, respectively. Earthquakes larger than those at Northridge and Kobe can occur in British Columbia.
Landslides threaten people and property in many parts of Canada, from the St. Lawrence Valley to the mountains of the Cordillera, causing $100-200 million in damage in Canada every year. Population growth is pushing development into formerly remote areas that are prone to landslides. Even small landslides are a significant threat to lives as well as transportation infrastructure as they disrupt the movement of goods, and are costly to clear. For example, in 1991, a small landslide near Logger's Creek, north of Vancouver, damaged a major highway; the cost to clear and repair the highway was $7 million. Construction of more roads and rail links increases the likelihood of transportation infrastructure being disrupted by landslides. Furthermore underwater landslides off the coast of British Columbia have destroyed wharves and warehouses and in 1914, a landslide at Hell's Gate, BC, prevented salmon from returning to their spawning grounds. Economic losses, in terms of reduced salmon runs, are estimated to be in the hundreds of millions of dollars and are still being felt, almost ninety years later.
Snow avalanches, on average, kill about 10 people in western Canada each year. This number is growing due to the rapid increase in winter back-country recreation.
Several young volcanoes in western North America are active or dormant and could erupt explosively, producing ash falls, pyroclastic flows, landslides, lahars, and floods that damage property and threaten life far from the source. The eruption of Mt. St. Helens in May 1980 demonstrated the kind of devastation that can be inflicted by volcanoes of the Cascade volcanic belt. The eruption claimed 57 lives and caused more than US $1 billion damage. A similar eruption at Mt. Baker, an active volcano, might cause serious damage in the Vancouver area.
One of the greatest hazards in Canada is flooding. The 1948 Fraser River flood caused about $200 million dollars in damage and displaced 16,000 people from their homes. Today, about $10 billion in property lies on the Fraser River floodplain behind protective river dykes. In 1993, a major flood in Winnipeg caused $500 million in damage. Further development of Canada's hinterland will result in increasing economic losses should a flood or other disaster strike.
Rapid climate change affects physical and biological processes and the landscape. Some natural disasters, such as floods and landslides, may occur more frequently with anticipated climate changes due to global warming. Climate change could also cause sea level to rise due to melting of glaciers, thermal expansion of oceans, and changes in ocean circulation. Sea-level rise will cause more flooding in coastal areas. Mining and forest harvesting may, in some cases, increase the risk of landslides under a new climate.