Switch Glacier:
North Mowich Glacier
This large glacier on the northwest side of Mount Rainier is separated from the Flett and Russell Glaciers by Ptarmigan Ridge on the northeast and is connected to the Edmonds Glacier on the south. It gives rise to the North Mowich River and was once called the Willis Glacier because it is below Willis Wall. Mowich is a Chinook jargon term for "deer"or "animal." (Reese, 2009)
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STATISTICS AS OF 2015 (Beason, 2017):
Aerial Extent:
1.99 ± 0.10 square miles
(5.14 ± 0.26 km2)
(Rank: 5 of 29)
Debris Cover:
0.43 ± 0.03 square miles
(1.11 ± 0.07 km2)
(Rank: 3 of 29)
Highest Elevation (Head):
12,195 feet
(3,717 m)
Lowest Elevation (Terminus):
5,360 feet
(1,634 m)
Elevation Range:
6,835 feet
(2,083 m)
Length:
2.78 miles
(4.47 km)
Average Slope:
28°
Average Flow Direction (Flows towards):
Northwest (316°)
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CHANGE IN EXTENT, 1896-2015 (Beason, 2017):
Units |
1896 |
1913 |
1971 |
1994 |
2009 |
2015 |
Area, mi2 |
4.28 |
3.10 |
2.42 |
2.36 |
2.01 |
1.99 |
Area, km2 |
11.07 |
8.03 |
6.26 |
6.11 |
5.21 |
5.14 |
Area change between periods
|
1913 |
1971 |
1994 |
2009 |
2015 |
1896 |
-1.17 mi2 (-3.04 km2) |
-1.86 mi2 (-4.81 km2) |
-1.92 mi2 (-4.97 km2) |
-2.27 mi2 (-5.87 km2) |
-2.29 mi2 (-5.93 km2) |
1913 |
-- |
-0.68 mi2 (-1.77 km2) |
-0.74 mi2 (-1.92 km2) |
-1.09 mi2 (-2.83 km2) |
-1.12 mi2 (-2.89 km2) |
1971 |
|
-- |
-0.06 mi2 (-0.15 km2) |
-0.41 mi2 (-1.05 km2) |
-0.43 mi2 (-1.12 km2) |
1994 |
|
-- |
-0.35 mi2 (-0.90 km2) |
-0.37 mi2 (-0.96 km2) |
2009 |
|
-- |
-0.02 mi2 (-0.06 km2) |
Percent change between periods
|
1913 |
1971 |
1994 |
2009 |
2015 |
1896 |
-27.5 % |
-43.5 % |
-44.8 % |
-53.0 % |
-53.5 % |
1913 |
-- |
-22.1 % |
-24.0 % |
-35.2 % |
-36.0 % |
1971 |
|
-- |
-2.4 % |
-16.8 % |
-17.8 % |
1994 |
|
-- |
-14.8 % |
-15.8 % |
2009 |
|
-- |
-1.2 % |
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ESTIMATED CHANGE IN VOLUME, 1896-2015 (George and Beason, 2017):
PLEASE see important notes about this, below...
Units |
1896 |
1913 |
1971 |
1981* |
1994 |
2009 |
2015 |
Volume, mi3 |
0.3402 |
0.2468 |
0.1923 |
0.2117 |
0.1876 |
0.1600 |
0.1580 |
Volume, km3 |
1.4181 |
1.0286 |
0.8017 |
0.8826 |
0.7822 |
0.6667 |
0.6587 |
* = 1981 was the only year that glacial volumes have been measured. See note below.
Basal Shear Stress (τ): 3,025.01 lbs/ft2
Volume change between periods
|
1913 |
1971 |
1981 |
1994 |
2009 |
2015 |
1896 |
-0.0934 mi3 (-0.3895 km3) |
-0.1479 mi3 (-0.6164 km3) |
-0.1285 mi3 (-0.5355 km3) |
-0.1526 mi3 (-0.6359 km3) |
-0.1803 mi3 (-0.7514 km3) |
-0.1822 mi3 (-0.7593 km3) |
1913 |
-- |
-0.0544 mi3 (-0.2268 km3) |
-0.0350 mi3 (-0.1460 km3) |
-0.0591 mi3 (-0.2464 km3) |
-0.0868 mi3 (-0.3619 km3) |
-0.0887 mi3 (-0.3698 km3) |
1971 |
|
-- |
0.0194 mi3 (0.0808 km3) |
-0.0047 mi3 (-0.0196 km3) |
-0.0324 mi3 (-0.1350 km3) |
-0.0343 mi3 (-0.1430 km3) |
1981 |
|
-- |
-0.0241 mi3 (-0.1004 km3) |
-0.0518 mi3 (-0.2158 km3) |
-0.0537 mi3 (-0.2238 km3) |
1994 |
|
-- |
-0.0277 mi3 (-0.1154 km3) |
-0.0296 mi3 (-0.1234 km3) |
2009 |
|
-- |
-0.0019 mi3 (-0.0080 km3) |
Percent change between periods
|
1913 |
1971 |
1981 |
1994 |
2009 |
2015 |
1896 |
-27.5 % |
-43.5 % |
-37.8 % |
-44.8 % |
-53.0 % |
-53.5 % |
1913 |
-- |
-22.1 % |
-14.2 % |
-24.0 % |
-35.2 % |
-36.0 % |
1971 |
|
-- |
10.1 % |
-2.4 % |
-16.8 % |
-17.8 % |
1981 |
|
-- |
-11.4 % |
-24.5 % |
-25.4 % |
1994 |
|
-- |
-14.8 % |
-15.8 % |
2009 |
|
-- |
-1.2 % |
With the exception of data in 1981, all values here are calculated estimates based on work by Driedger and Kennard (1986), which calculates glacier volumes with the following equations:
If Glacier Length (L) > 8,500 ft:

If Glacier Length (L) < 8,500 ft:

Basal shear stress (τ) is calculated as:

Where V is the calculated volume of the glacier (ft3), A is the calculated area of the glacier (ft2), ρ is the density of ice (1.779 slug/ft3), g is the acceleration of gravity (32.178 ft/s2), and α is the average slope of the glacier.
If you need a really good research project, recalculating the glacier volumes at Mount Rainier is the way to go!
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NOTES:
Data References:
Beason, 2017,
George and Beason, 2017,
Reese, 2009, and
Driedger and Kennard, 1986