Zum Inhalt springen

Mount Price (British Columbia)

aus Wikipedia, der freien Enzyklopädie
Dies ist eine alte Version dieser Seite, zuletzt bearbeitet am 23. Juli 2021 um 16:55 Uhr durch en>Volcanoguy (→Effects: added missing word). Sie kann sich erheblich von der aktuellen Version unterscheiden.

Vorlage:About Vorlage:Infobox mountain Mount Price is a small stratovolcano in the Garibaldi Ranges of the Pacific Ranges in southwestern British Columbia, Canada. It is located Vorlage:Convert southeast of the abandoned settlement of Garibaldi above the eastern flank of the Cheakamus River valley. With a summit elevation of Vorlage:Convert, it rises above the surrounding landscape on the western shore of Garibaldi Lake. The mountain contains a number of subfeatures, including Clinker Peak on its western flank, which was the source of two thick lava flows 15,000–12,000 years ago that ponded against glacial ice. These lava flows are structurally unstable, having produced large landslides as recently as the 1850s. A large provincial park surrounds Mount Price and other volcanoes in its vicinity.

Mount Price is associated with a small group of related volcanoes called the Garibaldi Lake volcanic field. This forms part of the larger Garibaldi Volcanic Belt, a north−south trending volcanic zone that represents a portion of the Canadian Cascade Arc. Mount Price began its formation 1.2 million years ago and continued intermittently until about 12,000 years ago. Although the mountain has not had an eruption since the early Holocene epoch, it could erupt again, which would potentially endanger the nearby populace. If this were to happen, relief efforts would be quickly organized. Teams such as the Interagency Volcanic Event Notification Plan are prepared to notify people threatened by volcanic eruptions in Canada.

Geology

Mount Price is one of the three principal volcanoes in the southern segment of the Garibaldi Volcanic Belt, attaining an elevation of Vorlage:Convert.[1][2] In contrast to most stratovolcanoes in Canada, Mount Price has a nearly symmetrical structure. It is one of several Garibaldi Belt volcanoes that have been volcanically active in the Quaternary period. Clinker Peak forms a breached volcanic crater on its western flank.[2] Oxidation of Price's volcanic rocks has given the mountain a red colour.[3]

Like other volcanoes in the Garibaldi Volcanic Belt, Mount Price formed as a result of subduction zone volcanism. As the Juan de Fuca Plate subducts under the North American Plate at the Cascadia subduction zone, it forms volcanoes and volcanic eruptions.[4] Unlike most subduction zones worldwide, there is no deep oceanic trench along the continental margin of Cascadia. There is also very little seismic evidence that the Juan de Fuca Plate is actively subducting. As a result, the existence of active volcanism in the Cascade Volcanic Arc is the best evidence for ongoing subduction. However, volcanic activity along the Cascade Arc has been declining over the last few million years. The probable explanation lies in the rate of convergence between the Juan de Fuca and North American plates. These two tectonic plates currently converge at a rate of Vorlage:Convert per year, only about half the rate of convergence from seven million years ago. This slowed convergence likely accounts for reduced seismicity and the lack of an oceanic trench.[2]

Volcanic history

A large rocky cliff rising above rubble with a person in the foreground standing on a rounded rock.
The Barrier is part of a thick lava flow that erupted from Clinker Peak 15,000–12,000 years ago

At least three phases of eruptive activity have been identified at Mount Price.[2] The first eruptive phase 1.2 million years ago deposited hornblende andesite lava and pyroclastic rocks on the floor of a cirque-like basin after an Early Pleistocene glacial event.[2][5] During the Middle Pleistocene about 300,000 years ago, volcanism of the second phase shifted westward and constructed the nearly symmetrical stratovolcano of Mount Price. Episodic eruptions during this phase of activity produced andesite and dacite lavas, as well as pyroclastic flows from Peléan activity. Later, the volcano was overridden by the Cordilleran Ice Sheet, which covered a large portion of western North America during glacial periods of the Quaternary.[2]

After the Cordilleran Ice Sheet retreated from higher elevations less than 15,000 years ago, andesite eruptions of the third eruptive phase occurred from a satellite vent at Price Bay.[2][6][5] This resulted in the creation of a small lava dome or scoria cone on Price's northern flank.[6][5] Possibly contemporaneous volcanism occurred at Clinker Peak with the eruption of two hornblende-biotite andesite lava flows.[2] They are both at least Vorlage:Convert thick and Vorlage:Convert long, extending to the northwest and southwest.[2][5] Their unusually large thickness is due to them ponding and cooling against the Cordilleran Ice Sheet when it still filled valleys at lower elevations.[5]

A prominent feature of the Clinker Peak lava flows are the levees that demarcate the lava channels. The northwest lava flow forms a volcanic dam known as The Barrier.[7] This retains the Garibaldi Lake system and has been the source of two large landslides in the past. The most recent major landslide in 1855-1856 resulted from failure along vertical rock fractures.[8] It travelled Vorlage:Convert down Rubble Creek to the Cheakamus valley, depositing Vorlage:Convert of rock.[8][9] The southwest lava flow forms a mountain ridge called Clinker Ridge.[7]

In contrast to the Mount Cayley and Mount Meager massifs, no hot springs are known in the Garibaldi area. However, there is evidence of anomalously high heat flow in Table Meadows near the southern flank of Mount Price and elsewhere. This indicates that magmatic heat is still present under the Garibaldi area and that it may be related to recent volcanic activity.[10]

Human history

Naming

A mountain rising above a lake in the foreground with glaciated mountains in the background.
Garibaldi Lake with Mount Price in the background

Mount Price has had at least three names throughout its history. It was originally named Red Mountain for its red appearance, but the date of when this name was adopted has not been cited.[11] Another peak west of Overlord Mountain was identified as Red Mountain on a 1923 sketch by Canadian mountaineer Neal M. Carter.[12][13] To avoid confusion, the name of this mountain was changed to Fissile Peak on September 2, 1930 for its fissility.[11][12]

In 1927, Canadian volcanologist William Henry Mathews (1919–2003) identified Mount Price as Clinker Mountain in articles and journals. The name Mount Price was adopted on September 2, 1930 after a committee of the Garibaldi Park Board was set up to deal with nomenclature. It was requested that the Geographic Board of Canada to adopt Mount Price for this mountain after Thomas E. Price, a former mountaineer and engineer of the Canadian Pacific Railway.[11] Clinker Peak and Clinker Ridge were both officially named on September 12, 1972 to retain Price's earlier name, Clinker Mountain.[14][15]

Protection and monitoring

The volcano and its eruptive products are protected in Garibaldi Provincial Park. Founded in 1927 as a Class A provincial park, this wilderness park covers an area of Vorlage:Convert. Lying within its boundaries are a number of other volcanoes, such as Mount Garibaldi and The Black Tusk. Located Vorlage:Convert north of Vancouver in the glaciated Coast Mountains, Garibaldi Provincial Park contains diverse vegetation, iridescent waters and a rich geological history. The park also has abundant wildlife, such as squirrels, chipmunks, Canada jays and flickers. Garibaldi Provincial Park is named after Mount Garibaldi, which is in turn named after the Italian patriot and soldier Giuseppe Garibaldi.[16]

Like other volcanoes in the Garibaldi Lake volcanic field, Mount Price is not monitored closely enough by the Geological Survey of Canada to ascertain its activity level. The Canadian National Seismograph Network has been established to monitor earthquakes throughout Canada, but it is too far away to provide an accurate indication of activity under the mountain. It may sense an increase in seismic activity if Price becomes highly restless, but this may only provide a warning for a large eruption; the system might detect activity only once the volcano has started erupting.[17] If Price were to erupt, mechanisms exist to orchestrate relief efforts. The Interagency Volcanic Event Notification Plan was created to outline the notification procedure of some of the main agencies that would respond to an erupting volcano in Canada, an eruption close to the Canada–United States border or any eruption that would affect Canada.[18]

Volcanic hazards

At least 63 volcanic events have occurred in the Garibaldi Lake volcanic field in the last 1.3 million years.[19] Since the early Holocene epoch, there has been no eruptive activity.[2] Future eruptions of Mount Price will probably be similar in character to those that have occurred throughout its 1.2 million year eruptive history.[5][7] The minimum annual probability of an eruption occurring in Canada is about one every 200 years; for an effusive eruption the probability is about one every 220 years and for a large explosive eruption the probability decreases to about one every 3,333 years. This indicates that an eruption in the foreseeable future is more likely to be characterized by fluid lava rather than major explosivity.[20] However, the majority of these effusive eruptions occur in the Northern Cordilleran Volcanic Province of northwestern British Columbia and central Yukon, which is the most active volcanic zone in Canada.[2][21] In the Garibaldi Volcanic Belt, eruptions occur less often, but it is the site of Canada's most explosive volcanism.[4] The change in eruptive style between the two volcanic zones is caused by the different tectonic processes that have formed them. Nevertheless, the possibility of passive lava eruptions occurring in the Garibaldi Volcanic Belt cannot be ruled out.[2]

Effects

Mount Price is near the highly populated southwest corner of British Columbia, indicating that it poses a serious threat to the surrounding area.[4][7] Although Plinian eruptions have not been identified at Mount Price, Peléan eruptions can also produce large amounts of volcanic ash that could significantly affect the nearby communities of Whistler and Squamish.[7] Mount Price is also situated in the immediate proximity of a major air traffic route.[22] Volcanic ash reduces visibility and can cause jet engine failure, as well as damage to other aircraft systems.[23] Peléan eruptions may cause short and long term water supply problems for the city of Vancouver and most of the Lower Mainland. The catchment area for the Greater Vancouver watershed is downwind from Mount Price. An eruption producing floods and lahars could destroy parts of the Sea to Sky Highway, threaten communities such as Brackendale and endanger water supplies from Pitt Lake. Fisheries on the Pitt River would also be at risk. These volcanic hazards become more serious as the Lower Mainland grows in population.[7] More than 60% of British Columbians live in the Lower Mainland, which is one of Canada's most rapidly changing ecoregions.[24][25] This is mostly due to its increasing population and economic development.[25]

A large snow-covered mountain towering above trees and a snow-covered lake on a clear day.
Mount Price and Clinker Peak

Because andesite is the main type of lava erupted from Mount Price, lava flows are a low to moderate hazard.[7] Andesite lava is intermediate in silica content, indicating that it has a higher viscosity than basaltic lava but is less viscous than dacite or rhyolite lava. As a result, andesite lava flows typically move slower than basaltic lava flows and are less likely to travel as far from their source. Dacite and rhyolite lavas are normally too viscous to flow far from a volcanic vent, resulting in the formation of lava domes.[26] An exception is the Vorlage:Convert long Ring Creek dacite lava flow from Opal Cone on the southeastern flank of Mount Garibaldi, a length that is normally attained by basaltic lava flows.[7]

Concerns about The Barrier's instability due to volcanic, tectonic or heavy rainfall activity prompted the provincial government to declare the area immediately below it unsafe for human habitation in 1980.[8] This led to the evacuation of the small resort village of Garibaldi nearby and the relocation of residents to new recreational subdivisions away from the hazard zone.[7][8] Should The Barrier completely collapse, Garibaldi Lake would be entirely released and downstream damage in the Cheakamus and Squamish rivers would be considerable, including major damage to the town of Squamish and possibly an impact-wave on the waters of Howe Sound that would reach Vancouver Island.[8] The landslide area is referred to as the Barrier Civil Defence Zone. Although landslides are unlikely to happen in the near future, warning signs are posted at the zone to make visitors aware of the potential danger and to minimize the chance of fatalities in the event of a slide. For safety reasons, BC Parks recommends visitors not to camp, stop or linger in the Barrier Civil Defence Zone.[16]

See also

Portal: Volcanoes – Mountains

References

Vorlage:Reflist

Vorlage:Commons category

Vorlage:Pacific Ranges Vorlage:Garibaldi Volcanic Belt

  1. ↑ Referenzfehler: Ungültiges <ref>-Tag; kein Text angegeben für Einzelnachweis mit dem Namen GVP.
  2. ↑ a b c d e f g h i j k l Referenzfehler: Ungültiges <ref>-Tag; kein Text angegeben für Einzelnachweis mit dem Namen HLK.
  3. ↑ J. L. Smellie, M. G. Chapman: Volcano-Ice Interaction on Earth and Mars. Geological Society of London, 2002, ISBN 1-86239-121-1, S. 202.
  4. ↑ a b c Garibaldi volcanic belt. In: Catalogue of Canadian volcanoes. Natural Resources Canada, 2. April 2009, archiviert vom Original am 15. Juni 2008; abgerufen am 21. Januar 2011.
  5. ↑ a b c d e f Peter B. Read: Late Cenozoic Volcanism in the Mount Garibaldi and Garibaldi Lake Volcanic Fields, Garibaldi Volcanic Belt, Southwestern British Columbia. In: Articles. 17. Jahrgang, Nr. 3. Geological Association of Canada, 1990, ISSN 1911-4850, S. 172, 173.
  6. ↑ a b Referenzfehler: Ungültiges <ref>-Tag; kein Text angegeben für Einzelnachweis mit dem Namen KD.
  7. ↑ a b c d e f g h i Garibaldi volcanic belt: Garibaldi Lake volcanic field. In: Catalogue of Canadian volcanoes. Natural Resources Canada, 1. April 2009, archiviert vom Original am 13. Mai 2008; abgerufen am 21. Januar 2011.
  8. ↑ a b c d e S.G. Evans, K.W. Savigny: Geology and Geological Hazards of the Vancouver Region, Southwestern British Columbia. Natural Resources Canada, Ottawa, Ontario 1994, ISBN 0-660-15784-5, Landslides in the Vancouver-Fraser Valley-Whistler region, S. 268, 270.
  9. ↑ Where do landslides occur? Government of British Columbia, archiviert vom Original am 18. August 2010; abgerufen am 21. Januar 2012.
  10. ↑ Vorlage:Cite report
  11. ↑ a b c Referenzfehler: Ungültiges <ref>-Tag; kein Text angegeben für Einzelnachweis mit dem Namen GL.
  12. ↑ a b Vorlage:Cite bcgnis
  13. ↑ Chic Scott: Pushing the Limits: The Story of Canadian Mountaineering. Rocky Mountain Books, Calgary, Alberta 2002, ISBN 0-921102-59-3, 122 (archive.org).
  14. ↑ Vorlage:Cite bcgnis
  15. ↑ Vorlage:Cite bcgnis
  16. ↑ a b Garibaldi Provincial Park. BC Parks, abgerufen am 20. Juni 2010.
  17. ↑ Monitoring volcanoes. In: Volcanoes of Canada. Natural Resources Canada, 26. Februar 2009, archiviert vom Original am 8. Juni 2008; abgerufen am 20. Januar 2012.
  18. ↑ Interagency Volcanic Event Notification Plan (IVENP). In: Volcanoes of Canada. Natural Resources Canada, 4. Juni 2008, archiviert vom Original am 14. Februar 2009; abgerufen am 20. Januar 2012.
  19. ↑ Peter Bobrowsky: Geologic Hazards in British Columbia. In: Volcanic Hazards. Geologic Hazards '91 Workshop, 1992, ISSN 0835-3530, S. 54 (bc.ca [PDF; abgerufen am 22. Januar 2012]).
  20. ↑ Mark V. Stasiuk, Catherine J. Hickson, Taimi Mulder: The Vulnerability of Canada to Volcanic Hazards. In: Natural Hazards. 28. Jahrgang, Nr. 2/3. Springer Netherlands, 2003, ISSN 0921-030X, S. 563, doi:10.1023/A:1022954829974.
  21. ↑ Stikine volcanic belt. In: Catalogue of Canadian volcanoes. Natural Resources Canada, 13. Februar 2008, archiviert vom Original am 8. Juni 2009; abgerufen am 23. Januar 2012.
  22. ↑ Volcanic hazards. In: Volcanoes of Canada. Natural Resources Canada, 2. April 2009, archiviert vom Original am 2. Februar 2009; abgerufen am 21. Januar 2012.
  23. ↑ Christina A. Neal, Thomas J. Casadevall, Thomas P. Miller, James W. Hendley II, Peter H. Stauffer: Volcanic Ash–Danger to Aircraft in the North Pacific. United States Geological Survey, 14. Oktober 2004, abgerufen am 21. Januar 2012.
  24. ↑ Welcome to the Lower Mainland Region. Government of British Columbia, abgerufen am 24. November 2012.
  25. ↑ a b B.C.'s Lower Mainland. Statistics Canada, 17. Januar 2018, abgerufen am 22. Juli 2021.
  26. ↑ Lava flows destroy everything in their path. In: Lava type dictates flow shape and travel distance. United States Geological Survey, 4. Juni 2008;.
Abgerufen von „https://de.wikipedia.org/w/index.php?title=Mount_Price_(British_Columbia)&oldid=248070166“