Tweedsmuir Glacier

Tweedsmuir Glacier - Canadian Glacier Inventory Project
Figure 1: Tweedsmuir Glacier in retreat
(Shangaan Webservices Inc, http, 2006).
  • 1973 (April): Tweedsmuir began to advance at its terminus (USGS, 2002).

  • 1973 (June/ July): peak activity in advancement occurred due to basal sliding (USGS, 2002).

  • 1973 (22 July 1973- 13 September 1973): advancing ice speeds were measured to be about 10m/day (USGS, 2002).

  • 1973 (winter): the large, piedmontlike lobe expanded and dammed the Alsek River temporarily (USGS, 2002).

  • 1973: ice cliffs at the river contact were roughly 25-30 m high and on the northern inland sublobe, thickness was about 15m. Thickness in the center was probably 50-100m (USGS, 2002).

  • 1974 (summer): The Alsek River flowed passed the Tweedsmuir, causing extreme ice calving into the river (USGS, 2002).

Tweedsmuir Glacier - Canadian Glacier Inventory Project
Figure 2: Ice flow lines and vectors 1973-1978 (USGS, 2002).

Tweedsmuir Glacier - Canadian Glacier Inventory Project
Figure 3: Ice flow lines based on ice flow vectors, 1973-1978
(USGS, 2002).

Location: St. Elias Mountains in the Alsek River Watershed (USGS, 2002).

Characteristics of Tweedsmuir Glacier

Type: surging (USGS, 2002).

Altitude: no data

Width: 1km (USGS, 2002).

Length: 70 km (USGS, 2002).

Volume/Mass: no data

Thermal Regime: warm glacier (surging) (USGS, 2002).

Interesting Facts:

  • Other glaciers in the Canadian Alsek Hydrologic System (USGS, http, 2002):
    • Dusty glacier
    • Lowell glacier
    • Fisher glacier
    • Verm Ritchie glacier
    • Battle glacier
    • Melbern glacier

  • Tweedsmuir ends in an expanded piedmontlike lobe that is in contact with the Alsek River (USGS, 2002).

  • The Alsek River terminates after a 16km stretch of rapids at the point where Tweedsmuir Glacier and Turnback Canyon come together and prevent further water flow ( see Figure 4) (Canadian Heritage Rivers System, 2007).

    Tweedsmuir Glacier - Canadian Glacier Inventory Project
    Figure 4: Tweedsmuir Glacier and Turnback Canyon prevent flow from the Alsek River (Environment Canada, http, 2006)

Canadian Heritage Rivers System, 2007. Alsek River. Available at: (Accessed on 22-02-07).

Environment Canada, 2006. Barrier to Salmon Crumbles on the Alsek. Pacific and Yukon Region Archive Columns. Available at: (Accessed on: 21-02-07).

Shangaan Webservices Inc., 2006. BC Parks-Tweedsmuir (North) Provincial Park, Chilcotin. Available:

United States Geological Survey, 2002. Glaciers of the St. Elias Mountains. Available at: (Accessed on 21-02-07).
(Accessed on: 21-02-07).

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