British Columbia is the westernmost province of Canada, bordered by the Pacific Ocean. With an area of it is Canada's third-largest province. The province is almost four times the size of the United Kingdom and larger than every United States 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.
Statistics
Total area: Land area: Water area: (2.1%)
Physical geography
British Columbia is customarily divided into three regions, the Interior, the Coast and the Lower Mainland (though the last-named is technically part of the Coast). These are broken up by a loose and often overlapping system of cultural-geographic regions, often based on river basins but sometimes spanning them. Examples of the former would be the Kootenays, the Okanagan, and the Chilcotin, while of the latter would be the Lillooet Country and Cariboo. Important subareas of these include the Fraser Valley, part of the Lower Mainland, the Fraser Canyon (which overlaps with various regions) and the Robson Valley, which is the uppermost basin of the Fraser River southeast of Prince George. Vancouver Island is seen as its own region within the Coast, as are the Haida Gwaii (Queen Charlotte Islands) and the Gulf Islands.
Terrain
The Canadian Rockies, Coast Mountains and Inside Passage provide some of British Columbia's renowned and spectacular scenery. These landforms provide the backdrop and context for a growing outdoor adventure and ecotourism industry. In the southwestern corner of B.C., the Lower Fraser Valley forms a flat, fertile triangle of intensively used land. The city of Penticton and the small towns Oliver, and Osoyoos have some of the warmest summer climates in Canada, although the hottest spots are the towns of Lillooet and Lytton in the Fraser Canyon. Nearly all of the Coast including much of Vancouver Island is covered by a temperate rain forest. One-third of the province consists of barren alpine tundra, icefields, and glaciers.
Mountains and mountain ranges The landforms of British Columbia include two major continental landforms, the Interior Plains in the province's northeast, the British Columbia portion of which is part of the Alberta Plateau. The rest of the province is part of the Western Cordillera of North America, often referred to in Canada as the Pacific Cordillera or Canadian Cordillera. The Cordillera is subdivided into four main "systems" (which are distinct from the corresponding region's geologic provinces):Landforms of British Columbia, S. Holland, BC Government Bulletin No. 48f
Eastern System
B.C.'s Eastern Mountain System comprises the dominant Canadian Rockies, with the Cariboo, Selkirk, Monashee, and Purcell ranges of the Columbia Mountains system in the south, and the Hart Ranges & Muskwa Ranges of the Northern Rocky Mountains to the north The Canadian Rockies incorporate the Canadian segment of the North American Rocky Mountains range. The southern end in Alberta and British Columbia borders Idaho and Montana of the United States. The northern end is at the Liard Plain in British Columbia.
Interior System The Interior System comprises the Interior Plateau and Interior Mountains (aka the Northern Interior Mountains) and the southern part of the Yukon Plateau. The major subdivisions of the Interior Mountains are the Cassiar Mountains, Omineca Mountains, Stikine Plateau, Skeena Mountains and Hazelton Mountains. Each has a variety of subranges and some definitions include the Tahltan Highland and Tagish Highland which may also be assigned to the Boundary Ranges of the Coast Mountains (see next). The major subdivisions of the Interior Plateau are the Nechako Plateau, the McGregor Plateau, the Fraser Plateau (which includes the Chilcotin Plateau and Cariboo Plateau and a number of small mountain ranges) and the Thompson Plateau. The Quesnel, Shuswap and Okanagan Highlands which flank the plateau to the east are sometimes seen as part of it, but are officially part of the Columbia Mountains range-system and are seen as subranges of the adjoining ranges, namely the Cariboo Mountains and Monashee Mountains.
Western System
The Western System comprises the Coast Mountains, the Canadian portion of the Cascade Mountains (known in the US as the Cascade Range), the southeasternmost Saint Elias Mountains and the Coastal Trough, which includes the Georgia Depression and its subunit the Fraser Lowland and other low-lying coastal areas.
The Western Mountain System's Coast Mountains are the westernmost range of the Pacific Cordillera, running along the western shore of the North American continent, extending south from the Alaska Panhandle and covering most of coastal British Columbia. The range is covered in dense temperate rainforest on its western exposures, the range rises to heavily glaciated peaks, including the largest temperate-latitude icefields in the world, and then tapers to the dry Interior Plateau on its eastern flanks, or to the subarctic boreal forest of the Skeena Mountains and Stikine Plateau.
Mount Waddington (4016 m) is the highest mountain within B.C. and Fairweather Mountain in the Fairweather Range of the Saint Elias Mountains on the B.C. and Alaska border has the highest point. Much of the B.C. coast has a fjord scenery, due to the many islands along the Pacific coast being the highest points of a partly submerged mountain range.
Insular System The Insular System comprises the Insular Mountains, which include the Vancouver Island Ranges and Queen Charlotte Mountains as well as the Nanaimo Lowland, Nahwitti Lowland and Hecate Depression.
British Columbia's principal mountains by range and height MountainHeight (m)MountainHeight (m)Saint Elias MountainsRocky Mountains (cont.)Fairweather Mountain (highest point on Alaska–B.C. boundary) 4,663Mount Assiniboine (on Alberta–B.C. boundary) 3,618Mount Quincy Adams (on Alaska–B.C. boundary) 4,133Mount Goodsir: North Tower 3,581Mount Root (on Alaska–B.C. boundary) 3,901Mount Goodsir: South Tower 3,520Coast MountainsSnow Dome (on Alberta–B.C. boundary) 3,520Mount Waddington 4,016Mount Bryce 3,507Mount Tiedemann 3,848Selkirk MountainsCombatant Mountain 3,756Mount Sir Sandford 3,522Asperity Mountain 3,716Cariboo MountainsSerra Peaks 3,642Mount Sir Wilfrid Laurier 3,520Monarch Mountain 3,459Purcell MountainsRocky MountainsMount Farnham 3,481Mount Robson 3,954Monashee MountainsMount Columbia (on Alberta–B.C. boundary) 3,747Mount Monashee 3,274Mount Clemenceau 3,642Hallam Peak 3,205 Source Statistics Canada
Volcanoes
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.Skiing the Pacific Ring of Fire and Beyond: Alaska & Northwest Canada 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: Silverthrone Mountain, Mount Meager massif, Wells Gray-Clearwater volcanic field, Mount Garibaldi, Mount Cayley, 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 -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 development of Wells Gray Provincial Park. As a result, if it had not been for the volcanic eruptions, it is not likely that such a large wilderness region would have been made.
Water