6. Brintnell-Bologna Icefield, NWT

Aerial view of the Brintnell Creek Glacier, looking west (photo: Margaret Demuth, August 2006)

Location and Physical Characteristics

  • Located within the Nahanni National Park Reserve at 62°06'N, 127°00'W, roughly 350 km west of Fort Simpson, NWT;
  • Brintnell-Bologna Icefield is a headwater icefield feeding two distinct outlet glaciers, and is about 30 km2 in area;
  • Elevations range from 1,770 m to 2,450 m a.s.l.;
  • The high peaks of the Ragged Range intercept Pacific moisture; heavy snowfalls and cold year-round temperatures at high elevations maintain several large icefields and hundreds of smaller mountain glaciers;
  • Mean annual temperature at nearby Tungsten (1,143 m) is -4.5 °C, and is estimated as -11 °C on the icefield plateau region;
  • Drainage is to the South Nahanni and Flat Rivers, feeding into the Liard River, and ultimately Mackenzie River. 


  • Glaciological investigations in the Ragged Range were initiated jointly between the Geological Survey of Canada (Natural Resources Canada) and Parks Canada Agency in 1995;
  • A glacier inventory was developed for the Ragged Range recently as part of a broader effort to expand the boundaries of Nahanni National Park Reserve;
  • The site is a focal part of ongoing glacier-climate observations as one of the reference sites of Natural Resources Canada's Cryosphere Geoscience Observatory (part of the State and Evolution of Canada's Glaciers project)

Current Science Focus and Instrumentation

  • Efforts focused on documentation of morphometric change of glaciers in the South Nahanni and Flat River headwaters above Virginia Falls, NWT, in relation to hydrometric and climatic variations;
  • Investigation of the seasonal evolution of river short-timescale variability and fingerprinting of regime shifts/tipping points in relation to changing spatial and temporal character of glacier storage;
  • Water sampling and isotopic analyses to fingerprint glacier melt water inputs in South Nahanni River and in glacier/nival tributary streams;
  • Seasonal mass balance measurement on Brintnell Glacier;
  • Two meteorological stations are in operation (on and off-ice at similar elevation); these were installed in August 2014.
  • Several nearby Meteorological Service of Canada observing stations and Water Survey of Canada discharge measurments at South Nahanni River above Virginia Falls and Flat River near the Mouth.   

Other Resources and Further Information

For further information contact:  

Mike Demuth, P.Eng., P.Geo.
Head of Glaciology Section, Geological Survey of Canada
Natural Resources Canada
601 Booth Street
Ottawa, ON, K1A 0E8

Glaciated vs. unglaciated drainages