Volcanoes of Canada
From Wikipedia, the free encyclopedia
Canada has examples of almost every type of volcano found on earth, including stratovolcanoes, calderas, cinder cones, shield volcanoes, maars and tuyas. Most of Canada's volcanoes are located in British Columbia. Several mountains that many British Columbians look at every day are active (but "sleeping") volcanoes. Most of them have erupted during the Pleistocene, Holocene, and others have the potential to erupt in the near future.
As quiet as they are, Canada is commonly considered to be a gap in a ring of more than 150 active volcanoes called the Pacific Ring of Fire, although it is a large region of over 200 volcanic centers, volcanoes and volcanic activity that have been active in the past two million years. The volcanoes in Canada are grouped into five major volcanic belts with diverse types of volcanoes and tectonic settings.
Contents |
[edit] Monitoring Canadian volcanoes
Volcano monitoring in Canada is a lower priority than other hazards, such as earthquakes, tsunamis and landslides. Most of our volcanoes are located in remote locations, even though some volcanoes pose a significant threat to local population. However, as for earthquake monitoring, future eruptions in Canada are expected and could have a large effect on people that live in the region. Over the past 50 years, the Geological Survey of Canada has known past activity at our volcanoes. However, there is still not enough knowledge about the occurrence of their eruptions to expect which volcanoes will possibly erupt next and what their effects will be. Volcano monitoring in Canada is continuing, but none of our volcanoes are being satisfactorily monitored to let scientists verify how active their magma chambers and systems are. If a Canadian volcano turns highly tense, the seismic monitoring system will possibly sense the growing of movement at the volcanoes.
[edit] Recent activity
The most recent volcanic activity was in the Stikine Volcanic Belt in British Columbia, about 150 years ago. It produced a 22.5 km long lava flow, which destroyed the Nisga'a villages and resulted in the death of approximately 2000 Nisga'a people by poisonous smoke and gases. The lava flows traveled south 5 km where they crossed the border into Alaska and dammed the Blue River. However, there have been 10 Canadian volcanoes that have been based on recent seismic activity, including: Castle Rock, Mount Edziza, Mount Cayley, Hoodoo Mountain, Lava Fork Valley, Crow Lagoon, Mount Silverthrone, Mount Meager, Wells Gray-Clearwater Volcanic Field and Mount Garibaldi.
[edit] Volcanic belts and fields
[edit] Chilcotin Plateau Basalts
The Chilcotin Plateau Basalts are a north-south range of volcanoes in southern British Columbia running parallel to the Garibaldi Volcanic Belt.
[edit] Garibaldi Volcanic Belt
The Garibaldi Volcanic Belt is the volcanic belt in southwestern British Columbia. It is one of the northern extensions of the Cascade Volcanic Belt in the United States.
[edit] Pemberton Volcanic Belt
The Pemberton Volcanic Belt is the volcanic belt at a low angle near Mount Meager in southwestern British Columbia. It is one of the northern extensions of the Cascade Volcanic Belt in the United States. It appears to merge into the Garibaldi Volcanic Belt, although the Pemberton is older then the Garibaldi Volcanic Belt. It was formed by the subduction of the Juan de Fuca Plate to its west.
[edit] Anahim Volcanic Belt
The Anahim Volcanic Belt is the volcanic belt that stretches from just north of Vancouver Island to near Quesnel British Columbia and is considered to be related from the North American Plate moving over a small hotspot.
[edit] Stikine Volcanic Belt
The largest volcanic belt is the Stikine Volcanic Belt. It forms a large area of volcanoes and volcanic activity in northwestern British Columbia and the Yukon Territory. It is the most active volcanic belt in Canada. The last eruptions in this belt were from Lava Fork Valley (150 BP), the Tseax River Cones (220 BP) and possible eruptions at Ruby Mountain (103 BP). The volcanoes are possibly related to extensional faulting, rifting and cracking along the Queen Charlotte Fault to the west.
[edit] Wrangell Volcanic Field
The Wrangell Volcanic Field is a volcanic field associated with the Pacific Plate being subducted under the North American Plate. This belt is largely in Alaska, but extends southwest into the Yukon Territory.
[edit] Wells Gray-Clearwater Volcanic Field
Volcanic activity has also created a large volcanic field, known as the Wells Gray-Clearwater Volcanic Field, which is possibly related to crustal thinning of the North American Plate. The most recent volcanic activity in the field was at Kostal Cone, about 400 years ago.
[edit] Volcanism outside of British Columbia and Yukon Territory
Volcanism has occurred in other regions, apart from British Columbia and the Yukon Territory. The Canadian Shield contains some of the most ancient volcanoes in Canada and on earth. It has over 150 volcanic belts (now deformed and eroded down to nearly flat plains) that range from 600 to 2800 million years old. Each belt probably grew by the coalescence of accumulations erupted from numerous vents, making the tally of volcanoes in the hundreds. Many of Canada's major ore deposits are associated with Precambrian volcanoes. Pillow lavas in the Northwest Territories are about 2600 million years old and are preserved in the Cameron River Volcanic Belt. The pillow lavas in rocks over 2 billion years old in the Canadian Shield signify that great oceanic volcanoes existed during the early stages of the formation of the Earth's crust. Ancient volcanoes play an important role in estimating Canada's mineral potential. Many volcanic belts bear ore deposits that are related to the volcanism. Consequently geologists study volcanic belts to understand the volcanoes and the environment in which they erupted, and to provide a working model for mineral exploration.
[edit] Major Volcanoes of Canada
- Mount Edziza
- Mount Meager
- Ilgachuz Range
- Itcha Range
- Rainbow Range
- Level Mountain
- Mount Garibaldi
- Mount Cayley
- Mount Silverthrone
[edit] See also
- List of volcanoes in Canada
- Canadian Shield
- Cascade Volcanic Belt
- Geology of the Pacific Northwest (Mostly of United States, but part Canada)
