Comparing the Recession of Glaciers in the
Torngat Mountains with Cirque Glaciers of the Canadian Rockies
George Hill
GE354
9 December 2015


Description of Torngat and Rocky Mountain
Localities

Paleoclimates of Boreal Canada during the
Holocene

Mass Balance and Topographic Controls on
Cirque Glaciers

Glacier Recession

- Wide variety of forms
- Indicators of global climate
- Sources of fresh water
- Torngat
Mountains poorly understood
Image Source


Extremely old rocks, Torngat Orogen, Granite and orthogneiss near coast → gneiss inland

Mountains on coast

Summers are rainy and foggy, winters dry and cold

195 ice masses, 1/3 under 0.05 km 2 and 8 above 0.5 km 2


Monashee Mountains: assemblage of metasedimentary rocks overlying granite/gneiss batholiths, 2500 m of relief from valley floor

Monashee Glacier size comparable to Torngats,
< 0.4 km 2

Consistent precipitation, affected by maritime and continental air masses


Central Canada
– Area from Ontario into BC
– Stable, consistent conditions

Labrador
– Climate responsive to global trends (LIA, MWP,
Dark Ages)
– Winter temperatures strongly correlated to precipitation


Torngat Mountains
– Backwall height associated with ELA
– Minimum ice mass elevations correlated with proximity to ocean, same with backwall height

Monashee Mountains
– Backwall Height → shadowing
– Avalanching and wind drifting

1981 m a.s.l
Abraham
Hidden
960
1010
Minaret 1290
Superguksoak 910
Mean ELA 1040
1982 m a.s.l
960
990
1260
860
1020
1983 m a.s.l
Mean m a.s.l
1030
1100
980
1030
1320
970
1290
910
1110 1050
After Rogerson, 1986
Backwall m
450
350
100
600


Average -2.6 m over 3 years 1981-1983 in large glaciers

Mass balance was positive after a cool summer and snowy winter

Mean annual temp was not a good predictor


Lost ~20% of area 2005-2007, ~53% since LIA

Elevation was best predictor of recession
– Topographic shading worse predictor

Result of less snowy winters and warmer summer

From Way, 2014


Warm winters should be snowier

Sea ice decrease is 20% per decade since
1968, so it must be warmer

Snow cover has also decreased in duration at the end of the season


Have not receded appreciably in last ~50 years

Glaciers without topography that favoured preservation did recede or disappear

Not accurate predictors of climate change


Cirque glaciers are highly variable and often influenced by topographic controls

Labrador is more heavily influenced by global climate

The recession of Torngat glaciers appears to be abnormal and still poorly understood

Rocky Mountains cirque glaciers are preserved by topography and are not good indicators of global climate

D'Arrigo, R., B. Buckley, S. Kaplan, and J. Woollett, 2003: Interannual to Multidecadal Modes of Labrador Climate
Variability Inferred from Tree Rings. Climate Dynamics, v. 20, pp. 219228.
DeBeer, C. M. and M. J. Sharp, 2009: Topographic Influences on Recent Changes of Very Small Glaciers in the
Monashee Mountains, British Columbia, Canada. Journal of Glaciology, v. 55, pp. 691-700.
McCoy, W. D., 1983: Holocene Glacier Fluctuations in the Torngat Mountains, Northern Labrador. physique et Quaternaire, v. 37, pp. 211-216.
Géographie
Menounos, C. B., G. Osborn, J. J. Clague, and B. H. Luckman, 2008: Latest Pleistocene and
Glacier Fluctuations in Western Canada. Quaternary Science, v. 28, pp. 20492074.
Holocene
Rogerson, R. J., 1986: Mass Balance of Four Cirque Glaciers in the Torngat Mountains of Northern Labrador,
Canada. Journal of Glaciology, v. 32, pp. 208-218.
Tennant, C., B. Menounos, R. Wheate, and J. J. Clague, 2012: Area change of glaciers in the Canadian Rocky
Mountains, 1919 to 2006. The Cyrosphere, v. 6, pp. 1541-1552.
Viau, A. E. and K. Gajewski, 2009: Reconstructing Millennial-Scale, Regional Paleoclimates of Boreal Canada during the Holocene. Journal of Climate , v. 22, pp. 316 –330.
Way, R. G., T. Bell, and N. E. Barrand, 2014: An Inventory and Topographic Analysis of Glaciers in the Torngat
Mountains, Northern Labrador, Canada. Journal of Glaciology, v. 60, pp. 945-956.
Way, R. G., T. Bell, and N. E. Barrand, 2015: Glacier change from the early Little Ice Age to 2005
Torngat Mountains, northern Labrador, Canada. Geomorphology, v. 246, pp. 558-569 .
in the

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