Tseax Cone

Coordinates: 55°06′38″N 128°53′56″W / 55.11056°N 128.89889°W / 55.11056; -128.89889
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Tseax Cone
Aiyansh Volcano
Aerial view of a sparsely tree-covered, cone-shaped volcano with a crater on its summit surrounded by forest and a lake in the background.
Tseax Cone with Melita Lake in the background
Highest point
Elevation609 m (1,998 ft)[1]
Coordinates55°06′38″N 128°53′56″W / 55.11056°N 128.89889°W / 55.11056; -128.89889[2]
Naming
EtymologyTseax River (Ksi Sii Aks)[3]
Native nameWil Ksi Baxhl Mihl (Nisga'a)[4]
English translationWhere the Fire Ran Out[5]
Geography
Tseax Cone is located in British Columbia
Tseax Cone
Tseax Cone
Location in British Columbia
Country
Tephra cones[6]
Type of rockBasanite and trachybasalt[6]
Volcanic regionNorthern Cordilleran Province[10]
Last eruption1690 ± 150 years[11]

Tseax Cone (

lava-dammed lake. It probably formed simultaneously with Tseax Cone but the timing of volcanism at the two centres is not precisely known; they were both active sometime in the last 800 years. The area has been designated as a provincial park
to protect these features.

Tseax Cone lies within an

provincial highways
and backcountry roads.

Names and etymology

Tseax Cone has been variously called Aiyansh Volcano, Aiyansh River Volcano, Tseax River Cone and Tseax Volcano.

local name for the volcano, Tseax Cone, was adopted 13 December 1991 on the National Topographic System map 103P/2.[2] To the Nisga'a, Tseax Cone is known as Wil Ksi Baxhl Mihl; in their language it means "Where the Fire Ran Out" which is a reference to the volcanic eruption that sent lava spewing out of the volcano.[4][5]

Geography

Location

Tseax Cone is located about 60 kilometres (37 miles) north of

cadastral survey subdivision at Tseax Cone is Cassiar Land District which lies north of 55th parallel north.[2][18]

Tseax Cone is situated within the Nass Mountains Ecosection, a

Lakelse Lake, Kitsumkalum Lake and Lava Lake are among some of the lakes in this ecosection.[19]

The area has a climate that is somewhat transitional between those of coastal and

subalpine Mountain Hemlock form rainforests in the area.[14][19] Areal wildlife includes marmots, goats, bears and moose.[20]

Lava flows

Jagged, moss-covered rocks in a valley bounded by lightly snow-covered mountains.
Moss-covered lava in Nass Valley

Lichens and mosses cover large portions of a lava flow sequence originating from Tseax Cone. They range in colour from green to yellow and reach thicknesses of a few centimetres.[21] In the Tseax River valley, the lava flows have been almost completely covered by dense rainforest. They have also been partially obscured by streams and small lakes, including Vetter Creek, Ross Lake and the Tseax River, all of which are in the Tseax River valley.[22] Melita Lake and Lava Lake have ponded behind the lava flow sequence, although Lava Lake had already existed before the lava was issued; it merely increased in depth.[23]

Despite being covered by lichens, mosses, rainforests and bodies of water, the lava flow sequence is easily recognizable from aerial and satellite imagery, as well as

lodgepole pine and cottonwood forests continue to develop on the lava flows in an increasingly wetter and milder climate. The growth of these forests is bolstered by the deposition of silt on the lava flows by local streams, providing soil for vegetation.[24]

Geology and geomorphology

Background

Tseax Cone is one of the southernmost volcanoes in the

peralkaline[a] phonolite, trachyte and comendite are locally abundant. These rocks were deposited by volcanic eruptions from 20 million years ago to as recently as a few hundred years ago. The cause of volcanic activity in the Northern Cordilleran Volcanic Province is thought to be due to rifting of the North American Cordillera driven by changes in relative plate motion between the North American and Pacific plates.[26]

Structure

Tseax Cone has an elevation of 609 metres (1,998 feet) and consists of two nested structures: a smaller inner cone and a larger external

lava fountaining at the larger satellite cone.[28]

A sparsely tree-covered cone of volcanic rubble with a bowl-shaped crater on the top.
Aerial view of Tseax Cone from the southeast

Tseax Cone was the source of four distinct lava flows, all of which were probably erupted over a timespan of weeks to a few months.

ʻaʻā[d] and are rich in phenocrysts.[23]

All of the lava flows from Tseax Cone contain intact and collapsed

Coulthard Cave in the Canadian Rockies.[31]

Tseax Cone and its eruptive products are basanitic and

Coast Plutonic Complex are present adjacent to Tseax Cone.[14]

Age controversy

The exact timing of volcanism at Tseax Cone has been a subject of controversy due to there being no direct written accounts.

magmatic system.[36]

A field of moss-covered rocks with a couple trees in the foreground and snow-covered mountains in the background.
Tseax Cone lava flow in Nass Valley

Radiocarbon dating of trees killed by lava from Tseax Cone has also given inconclusive results. A lava-encased cottonwood near the Nass River was reported by Sutherland Brown in 1969 and Jack Souther in 1970 to have yielded a radiocarbon date of 220 ± 130 years. However, Lowdon et al. stated in a 1971 Radiocarbon article that this date was uncorrected and should in fact be 250 ± 130 years.[29] In 2001, M.C. Roberts and S. McCuaig reported in The Canadian Geographer that a wood fragment of a lava-encased tree yielded a radiocarbon date of 220 ± 130 years; they gave a corrected date of 230 ± 50 years.[37] The latter two radiocarbon dates were recalibrated by Michael D. Higgins in 2008 using calibration software and reinterpreted the age of the Tseax Cone eruption at between 1668 and 1714.[9][36] Charred wood beneath tephra about 890 metres (2,920 feet) northwest of Tseax Cone was reported by Williams-Jones et al. in 2020 to have yielded radiocarbon dates of 190 ± 15 years and 390 ± 15 years.[38]

It has been generally agreed by researchers that the Tseax Cone lava flows were emplaced during a single eruption.

geochemical data supporting the hypothesis that the inner tephra cone, external spatter rampart, satellite cones, lava flows and tephra deposits were all formed during a single period of activity.[42]

Hazards and monitoring

Trees and jagged moss-covered rock reflecting on water in the foreground.
Nass Valley lava flow

The question of whether Tseax Cone formed during one or more distinct eruptive episodes has important implications for future activity and hazard mitigation efforts.[6] Renewed activity from Tseax Cone is unlikely if the volcano is monogenetic. This is because monogenetic volcanoes are typically considered to erupt only once and to be short-lived.[43] If Tseax Cone is polygenetic, future activity could produce lava flows and potentially block local streams as happened previously. Damming of the Nass River by lava flows could negatively affect the salmon fisheries on that river. Carbon dioxide emissions from Tseax Cone could pose a threat to local inhabitants due to the gas's ability to replace oxygen in low-lying areas and poorly ventilated structures. Another potential hazard relating to future activity from Tseax Cone is the ignition of wildfires by eruptions as the area contains vegetation.[7]

Like other volcanoes in Canada, Tseax Cone 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 volcano. It may sense an increase in seismic activity if Tseax Cone 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.[44] If Tseax Cone 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.[45]

Human history

Indigenous peoples

Rubbly moss-covered lava rock with trees in the background.
Detail of lava flow in Nass Valley

Tseax Cone is a prominent figure in Nisga'a history and culture due to its association with a natural disaster.[35] According to Nisga'a legends, the Tseax Cone eruption caused the deaths of 2,000 people and the destruction of at least three villages on the banks of the Nass River.[6][7] This would make it the deadliest geological disaster in Canada and the second-worst natural disaster in Canadian history by death toll, succeeded only by the 1775 Newfoundland hurricane which caused at least 4,100 fatalities.[6][46] The three Nisga'a villages destroyed by the eruption have been named Lax Ksiluux, Lax Ksiwihlgest and Wii Lax K'abit.[6][47] Early 19th century Nisga'a accounts of the Tseax Cone eruption were reported by anthropologist Marius Barbeau in 1935 as follows:

...the volcanic eruption soon after broke out. First there was smoke, like that coming out of a house, a big pillar of smoke. It was as if a house was burning on the mountain top. The people saw a big fire. The fire came down the side in their direction, but not as fast as forest fire. It moved down slowly, very slowly. It was strange and frightful. It was dangerous! There were fumes spreading ahead, and those who smelled them were smothered. They died and their body stiffened like rock. Frightened, the people of one tribe dug holes in the ground like underground lodges, and hid within, scared as they were of the mountain spirits. Likewise, the other tribe. That did not keep other people from dying of the fumes, mostly in the lower of the villages. As soon as the smoke dispersed some people ran away; a great many others stayed on. They did not suffer any more from the smoke. The fire then rolled down like a river, filled the lake, and for a time the water was a bed of flames. The stone was red and hot there for many days. As far as it went, all the way, it was flowing red. It started from the river where the people fished salmon, away up there, and ran down to the place where the canyon now is...[35]

The "poisonous smoke" mentioned in Barbeau's report may have been odourless carbon dioxide.[7] It has been hypothesized that the Nisga'a casualties resulted from a carbon dioxide gravity current released by the sudden overturning of a former marshy lake adjacent to the destroyed Nass Valley villages. This overturning may have been caused by earthquakes accompanying the Tseax Cone eruption or by the sudden heating of lake waters when lava entered the Nass River.[48] Another hypothesis proposed by researchers is that while some of the Nisga'a attempted to escape the eruption by canoe on the Nass River, they were killed by boiling river water or were swept away in a flood as lava displaced the river.[48][49] Some of the Nisga'a deaths may have also resulted from wildfires ignited by the lava.[48]

The Nisga'a also recall the disruption of the Tseax River, stating that "before the volcanic eruption, when our people lived here at Wii Lax K'ap, there was a stream close by where salmon spawned. The stream bed had white sand and they could easily spot the salmon going up stream. This stream was thus named Ksi Gimwits'ax. Years later [after the volcanic eruption] when this stream resurfaced, and though the Nisga'a knew it was the same tributary, it was renamed Ksi Sii Aks."[3] A salamander species that once inhabited the bay area of Gitwinksihlkw on the Nass River is said to have disappeared or became extinct following the Tseax Cone eruption.[47]

Protection

Tseax Cone and its eruptive products are protected in Nisga'a Memorial Lava Bed Provincial Park.[7] This 17,717-hectare (43,780-acre) protected area was founded in 1992 to preserve the volcanic landscape and to honour the 2,000 Nisga'a people who died during the Tseax Cone eruption.[7][20] It was the first provincial park in British Columbia to be managed by both BC Parks and a First Nation, as well as the first provincial park in British Columbia to combine indigenous culture and natural features.[20] The former Nisga'a Memorial Lava Bed Recreation Area was annexed into Nisga'a Memorial Lava Bed Provincial Park in 1995.[50]

Accessibility

The Tseax Cone lava flows are most easily accessed by travelling the Nisga'a Highway north of Terrace for 100 kilometres (62 miles), the final 30 kilometres (19 miles) of which is unpaved. An alternative route to the lava flows involves travelling the paved Stewart–Cassiar Highway north of Kitwanga for 78 kilometres (48 miles) to the Cranberry River.[20] From there, the unpaved Nass Forest Service Road extends 86 kilometres (53 miles) southwest to Gitlaxt'aamiks which lies on the northeastern edge of the lava flows.[12][20] Access to Tseax Cone is limited only to a 6-kilometre-long (3.7-mile) guided hiking tour from an access road 1.4 kilometres (0.87 miles) north of the Lava Lake picnic site on the Nisga'a Highway.[20]

See also

Notes

  1. ^ Peralkaline rocks are magmatic rocks that have a higher ratio of sodium and potassium to aluminum.[25]
  2. ^ Pāhoehoe is basaltic lava with a smooth, glassy, undulating and porous surface.[25]
  3. ^ Phenocrysts are large, conspicuous crystals in magmatic rocks with porphyritic texture.[25]
  4. ^ ʻAʻā is lava with a rough rubbly surface composed of broken blocks called clinkers.[30]

References

  1. ^ a b "Tseax River Cone: General Information". Global Volcanism Program. Smithsonian Institution. Archived from the original on 2021-10-29. Retrieved 2021-11-17.
  2. ^ a b c d e f g "Tseax Cone". BC Geographical Names. Retrieved 2021-11-17.
  3. ^ a b "Ksi Sii Aks". BC Geographical Names. Archived from the original on 2021-11-27. Retrieved 2022-03-29.
  4. ^ a b c d Le Moigne et al. 2020, p. 363.
  5. ^ a b "Lava beds and other reasons to love northern British Columbia". Postmedia Network. 2019-11-06. Archived from the original on 2021-04-21. Retrieved 2022-01-12.
  6. ^ a b c d e f g h Williams-Jones et al. 2020, p. 1238.
  7. ^ a b c d e f g "Tseax Cone". Catalogue of Canadian volcanoes. Natural Resources Canada. 2005-08-19. Archived from the original on 2008-01-11. Retrieved 2022-01-12.
  8. ^ a b "Tseax Cone". Geographical Names Data Base. Natural Resources Canada. Retrieved 2023-10-06.
  9. ^ a b c d Williams-Jones et al. 2020, p. 1242.
  10. ^
    ISBN 978-3-319-44593-9
    .
  11. ^ "Tseax River Cone: Eruptive History". Global Volcanism Program. Smithsonian Institution. Archived from the original on 2021-10-29. Retrieved 2021-11-17.
  12. ^ a b Williams-Jones et al. 2020, p. 1239.
  13. ISBN 0-7748-0636-2
    .
  14. ^ a b c Le Moigne et al. 2020, p. 364.
  15. ^ Denton, George H. (1975). "Glaciers of the Interior Ranges of British Columbia". Mountain Glaciers of the Northern Hemisphere (Report). Vol. 1. American Geophysical Society. p. 662. Retrieved 2023-10-07.
  16. ^ "Melita Lake". BC Geographical Names. Archived from the original on 2021-11-26. Retrieved 2023-10-07.
  17. ^ a b "Crater Creek". BC Geographical Names. Archived from the original on 2021-11-26. Retrieved 2023-10-07.
  18. ^ "Cassiar Land District". BC Geographical Names. Archived from the original on 2018-06-27. Retrieved 2023-10-07.
  19. ^
    OCLC 613357103
    .
  20. ^ a b c d e f "Anhluut'ukwsim Lax̱mihl Angwinga'asanakwhl Nisga'a [a.k.a. Nisga'a Memorial Lava Bed Park]". BC Parks. Archived from the original on 2024-01-18. Retrieved 2023-10-24.
  21. ^ a b Le Moigne et al. 2020, pp. 365, 367.
  22. ^ Le Moigne et al. 2020, p. 367.
  23. ^ a b c Le Moigne et al. 2020, p. 369.
  24. ^ "Researchers Investigate how Vegetation is Changing at Nisga'a Memorial Lava Bed Park". Government of British Columbia. 2019-11-14. Archived from the original on 2023-06-08. Retrieved 2023-10-23.
  25. ^
    ISBN 0-07-141044-9
    .
  26. ISSN 0016-7606
    .
  27. ^
    ISSN 2296-6463
    .
  28. ^ a b c d e f Le Moigne et al. 2020, p. 365.
  29. ^ a b c d Williams-Jones et al. 2020, p. 1241.
  30. ^ "USGS Volcano Hazards Program Glossary". United States Geological Survey. 2018. Archived from the original on 2023-11-27. Retrieved 2023-12-22.
  31. doi:10.1080/00040851.1975.12003851 (inactive 31 January 2024).{{cite journal}}: CS1 maint: DOI inactive as of January 2024 (link
    )
  32. ^ Le Moigne et al. 2020, pp. 364, 368.
  33. ^ Williams-Jones et al. 2020, pp. 1241, 1250.
  34. ^ Williams-Jones et al. 2020, pp. 1238, 1241.
  35. ^ a b c Williams-Jones et al. 2020, p. 1250.
  36. ^
    ISSN 0377-0273
    .
  37. ^ Williams-Jones et al. 2020, pp. 1241, 1242.
  38. ^ Williams-Jones et al. 2020, pp. 1239, 1242.
  39. ^
    doi:10.1139/e78-111
    .
  40. ^ Williams-Jones et al. 2020, p. 1248.
  41. ^ Williams-Jones et al. 2020, pp. 1242, 1243.
  42. ^ Williams-Jones et al. 2020, pp. 1238, 1247.
  43. S2CID 259277907
    .
  44. ^ "Monitoring volcanoes". Volcanoes of Canada. Natural Resources Canada. 2009-02-26. Archived from the original on June 8, 2008. Retrieved 2022-04-09.
  45. ^ "Interagency Volcanic Event Notification Plan (IVENP)". Volcanoes of Canada. Natural Resources Canada. 2008-06-04. Archived from the original on February 14, 2009. Retrieved 2022-04-09.
  46. ^ "Volcano Watch — Volcanoes in Canada, eh?". United States Geological Survey. 2021-07-01. Archived from the original on 2022-11-03. Retrieved 2023-10-22.
  47. ^ a b "Gitwinksihlkw". BC Geographical Names. Archived from the original on 2020-02-18. Retrieved 2023-11-30.
  48. ^ a b c Gallo, Rose (2018). History and Dynamics of Explosive Volcanism at Tseax Cone, British Columbia (BSc thesis). University of British Columbia. p. 5. Retrieved 2023-10-21.
  49. ^ Hickson, C.J.; Spurgeon, T.C.; Cocking, R.B.; Russel, J.K.; Woodsworth, G.J.; Ulmi, M.; Rust, A.C. (2007). "Tseax Volcano: A Deadly Basaltic Eruption in North-Western British Columbia, Canada". Geological Society of America. Archived from the original on 2023-06-04. Retrieved 2023-10-24.
  50. ^ "Nisga'a Memorial Lava Bed Park". BC Geographical Names. Archived from the original on 2016-04-25. Retrieved 2023-10-22.

Sources

External links

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