page_title: Geography of British Columbia
section_title: Volcanoes
hierarchical_section_title: Geography of British Columbia / Physical geography / Terrain / Volcanoes
caption_attribution_description: The Mount Meager volcanic complex as seen from the east near Pemberton, BC. Summits left to right are Capricorn Mountain, Mount Meager, and Plinth Peak.
context_page_description: British Columbia is the westernmost province of Canada, bordered by the Pacific Ocean. With an area of 944,735 square kilometres it is Canada's third-largest province. The province is almost four times the size of United Kingdom and larger than every U.S. state except Alaska. It is bounded on the northwest by the U.S. state of Alaska, directly north by Yukon and the Northwest Territories, on the east by Alberta, and on the south by the U.S. states of Washington, Idaho, and Montana. Formerly part of the British Empire, the southern border of British Columbia was established by the 1846 Oregon Treaty. The province is dominated by mountain ranges, among them the Canadian Rockies but dominantly the Coast Mountains, Cassiar Mountains, and the Columbia Mountains. Most of the population is concentrated on the Pacific coast, notably in the area of Vancouver, located on the southwestern tip of the mainland, which is known as the Lower Mainland. It is the most mountainous province of Canada.
context_section_description: Although little-known to the general public, British Columbia is home to a huge area of volcanoes and volcanic activity in the Pacific Ring of Fire. Several mountains that many British Columbians look at every day are dormant volcanoes. Most of them have erupted during the Pleistocene and Holocene. Although none of Canada's volcanoes are currently erupting, several volcanoes, volcanic fields, and volcanic centers are considered potentially active, 49 of which have erupted in the past 10,000 years and many of which have been active in the past two million years. There are hot springs at some volcanoes while 10 volcanoes in British Columbia appear related to seismic activity since 1975, including: Mount Silverthrone, Mount Meager massif, Wells Gray-Clearwater volcanic field, Mount Garibaldi, Mount Cayley massif, Castle Rock, The Volcano, Mount Edziza, Hoodoo Mountain and Crow Lagoon. Numerous shield volcanoes developed during the Tertiary period in north-central British Columbia and some were active intermittently to recent times. Mount Edziza and Level Mountain are most spectacular examples. Mount Edziza is a stratovolcano consisting of a basal shield of basaltic flows surmounted by a central vent and flanked by numerous satellite cones, ash beds and blocky lavas. The complex has a long history of volcanic eruption that began about 10 million years ago and ended about 1300 years ago. The volcanoes are grouped into four volcanic belts with different tectonic settings.
  The Garibaldi Volcanic Belt is a north-south range of volcanoes in southwestern British Columbia. It is the northern extension of the Cascade Volcanic Arc in the United States and contains the most explosive young volcanoes in Canada. It was formed by subduction of the Juan de Fuca Plate at the Cascadia subduction zone. Eruption styles within the belt range from effusive to explosive, with compositions from basalt to rhyolite. The most recent major catastrophic eruption was the 2350 BP eruption of the Mount Meager massif. It produced an ash column at least 20 km high into the stratosphere and dammed the Lillooet River with breccia.
  The Anahim Volcanic Belt is an east-west line of volcanoes. These volcanoes probably formed when the North American Plate moved over the Anahim hotspot. The hotspot is considered similar to the one feeding the Hawaiian Islands. The last volcanic eruption within the belt was about 7000 years ago at a small cinder cone called Nazko Cone.
  The Northern Cordilleran Volcanic Province (sometimes called the Stikine Volcanic Belt) is the most active volcanic region in Canada, containing more than 100 volcanoes. Several eruptions are known to have occurred within this region in the past 400 years and contains Canada's largest volcanoes. It formed as a result of faulting, cracking, rifting and the interaction between the Pacific and the North American plates.
  The Chilcotin Group in southern British Columbia is thought to have formed as a result of back-arc extension behind the Cascadia subduction zone.
  The Wells Gray-Clearwater volcanic field in southeastern British Columbia consists of numerous small, basaltic volcanoes and extensive lava flows. Many individual volcanoes in the field have been active for the last 3 million years during which time the region was covered by thick glacial ice at least twice, prior to the well known Fraser Glaciation (also known as the Wisconsin Glaciation). The origin of the volcanism is yet unknown but is probably related to crustal thinning. The last eruption in the field was at Kostal Cone in 1500. Volcanism within the field has also created the 465-foot (142 m)-high Helmcken Falls, which is the fourth highest waterfall in Canada. It owes its foundation to the deposits of volcanic rock that were placed down in the wide valley of the Murtle River. Layer upon layer of fresh lava created flat areas, over which enormous floods flowed during the last ice age. These floods shaped the upright cliff in the lava flows over which the river now flows. The protection of Helmcken Falls was one of the major causes for the
caption: The Mount Meager massif as seen from the east near Pemberton, BC. Summits left to right are Capricorn Mountain, Mount Meager, and Plinth Peak
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