Saint Elias Mountains

The Saint Elias Mountains (French: Chaîne Saint-Élie) are a subgroup of the Pacific Coast Ranges, located in southeastern Alaska in the United States, Southwestern Yukon and the very far northwestern part of British Columbia in Canada. The range spans Wrangell-St. Elias National Park and Preserve in the United States and Kluane National Park and Reserve in Canada and includes all of Glacier Bay National Park in Alaska. In Alaska, the range includes parts of the city/borough of Yakutat and the Hoonah-Angoon and Valdez-Cordova census areas.[1]

Saint Elias Mountains
Mt. Saint Elias
Highest point
Peak	Mount Logan
Elevation	5,959 m (19,551 ft)
Listing
Coordinates	60°34′02″N 140°24′10″W
Dimensions
Length	300 mi (480 km)
Width	90 mi (140 km)
Area	112,509 km^2 (43,440 sq mi)
Geography
Saint Elias Mountains, east of the Wrangell Mountains
Countries	United States and Canada
States/Provinces	Alaska, Yukon and British Columbia
Range coordinates	60°30′N 139°30′W
Parent range	Pacific Coast Ranges
Borders on	Wrangell Mountains

This mountain range is named after Mount Saint Elias, which in turn was named in 1741 by the Danish explorer Vitus Bering.[2]

Geology

The St. Elias Mountains form the highest coastal mountain range on Earth. It formed due to the subduction of the Yakutat microplate underneath the North American Plate. The Yakutat microplate is a wedge shaped oceanic plateau with a thickness of 20 to 30 kilometres (12 to 19 mi).[3] Similar to the adjacent Pacific plate, which has a crustal thickness of 7 kilometres (4.3 mi), the Yakutat plate is moving northwestward at a rate of 50 millimetres (2 in) per year with respect to North America.[4] The Yakutat plate is transported northwards along the active Fairweather Fault, which probably started more than 35 million years ago.[5] Due to its thickness, the Yakutat plate is buoyant, resulting in surface uplift of the overriding North American plate, which formed the Talkeetna Mountains and the Alaska Range in Southcentral Alaska, located above the subducted part of the Yakutat plate.[5]

The St. Elias Mountains formed at the plate boundary between the Yakutat and North American plates. The up-to-12-kilometre (7.5 mi)-thick sediments that have been deposited on top of the Yakutat plate became imbricated and deformed as they were scraped off and compose today the southern (coastal) flanks of the St. Elias Mountains. In contrast the high elevated regions of the drainage divide (Bagley Ice Field, Seward Glacier) and north of it are composed of rocks that are part of the North American plate.[6] The highest peaks of the St. Elias Mountains are located in the high ice field region of the Kluane National Park (Mount Logan, Mount Vancouver) and north of the Malaspina Glacier (Mount Saint Elias, Mount Cook), in the region known as the St. Elias syntaxis. At the syntaxis region the tectonic style changes from strike-slip motion along the Fairweather Fault to collision west of Malaspina Strait. This tectonic transition concentrates stress in the crust at the syntaxis that together with efficient glacial erosion results in positive feedback processes that through time forms extreme high mountain peaks and local relief, and rapid exhumation of rocks from up to 10 km depths to the surface.[7]

Ranges

The mountains are divided by the Duke Depression, with the shorter, more rounded Kluane Ranges to the east, and the higher Icefield Ranges to the west. Sub-ranges of the Saint Elias include the Alsek Ranges, the Fairweather Range, and the Centennial Range.[8]

Highest mountains

The highest mountains of the range include:

Mountain	Height		Location	Notes
	m	ft
Mount Logan	5,959	19,551	Yukon	Highest mountain in Canada
Mount Saint Elias	5,489	18,008	Alaska-Yukon	Second highest in both Canada and the United States
Mount Lucania	5,226	17,147	Yukon	#3 in Canada
King Peak	5,173	16,971	Yukon	#4 in Canada
Mount Steele	5,073	16,644	Yukon	#5 in Canada
Mount Bona	5,005	16,421	Alaska	#5 in the United States
Mount Wood	4,842	15,885	Yukon
Mount Vancouver	4,812	15,787	Yukon
Mount Churchill	4,766	15,638	Alaska
Mount Slaggard	4,742	15,557	Yukon
Mount Macaulay	4,690	15,387	Yukon
Mount Fairweather	4,671	15,325	Alaska-British Columbia	#1 in British Columbia[9]
Mount Hubbard	4,577	15,015	Yukon
Mount Bear	4,520	14,831	Alaska
Mount Walsh	4,507	14,787	Yukon
Mount Alverstone	4,439	14,565	Alaska-Yukon
University Peak	4,410	14,470	Alaska
McArthur Peak	4,389	14,400	Yukon
Mount Augusta	4,289	14,070	Alaska-Yukon
Mount Kennedy	4,250–4300	~14,000	Yukon
Mount Cook	4,196	13,766	Alaska-Yukon

Notes

1. "Saint Elias Mountains". Geographic Names Information System. United States Geological Survey. Retrieved 2007-12-03.
2. "Saint. Elias Mountains". BC Geographical Names. Retrieved 2013-12-27.
3. Christeson, G.L.; Gulick, S.P.; van Avendonk, H.J.; Worthington, L.L.; Reece, R.S.; Pavlis, T.L. (2010). "The Yakutat terrane: Dramatic change in crustal thickness across the Transition fault, Alaska". Geology. 38 (10): 895–898. doi:10.1130/G31170.1.
4. Elliott, J.L.; Larsen, C.F.; Freymueller, J.T.; Motyka, R.J. (2010). "Tectonic block motion and glacial isostatic adjustment in southeast Alaska and adjacent Canada constrained by GPS measurements". Journal of Geophysical Research. 115: B09407. doi:10.1029/2009JB007139.
5. Finzel, E.S.; Trop, J.M.; Ridgway, K.D.; Enkelmann, E. (2011). "Upper plate proxies for flat-slab subduction processes in southern Alaska". Earth and Planetary Science Letters. 303 (3–4): 348–360. doi:10.1016/j.epsl.2011.01.014.
6. Plafker, G.; Berg, H.C. (1994). The Geology of Alaska. Boulder: Geological Society of America. pp. 389–449.
7. Enkelmann, E.; Zeitler, P.K.; Pavlis, T.L.; Garver, J.I.; Ridgway, K.D. (2009). "Intense localized rock uplift and erosion in the St. Elias orogen of Alaska". Nature Geoscience. 2 (5): 360–363. doi:10.1038/NGEO502.
8. "Saint Elias Mountains". Bivouac.com. Retrieved 2013-03-15.
9. Mount Fairweather is only partly in British Columbia. The highest peak entirely within British Columbia is Mount Waddington in the Coast Range, 4019 m (13186 ft).

References

• Richter, Donald H.; Preller, Cindi C.; Labay, Keith A.; Shew, Nora B. (2006). Geologic Map of the Wrangell-Saint Elias National Park and Preserve, Alaska. USGS Scientific Investigations Map 2877.
• Winkler, Gary R. (2000). A Geologic Guide to Wrangell—Saint Elias National Park and Preserve, Alaska: A Tectonic Collage of Northbound Terranes. USGS Professional Paper 1616. ISBN 978-0-607-92676-7.
• Wood, Charles A.; Kienle, Jürgen, eds. (1990). Volcanoes of North America. Cambridge University Press. ISBN 978-0-521-43811-7.