Switch Glacier:
South Tahoma Glacier
The South Tahoma Glacier is south of the Tahoma Glacier on the southwest side of Mount Rainier. The South Tahoma Glacier is separated from the Pyramid Glacier on the southeast by Success Cleaver and is drained by Tahoma Creek. (Reese, 2009)
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STATISTICS AS OF 2015 (Beason, 2017):
Aerial Extent:
0.77 ± 0.04 square miles
(2.00 ± 0.10 km2)
(Rank: 14 of 29)
Debris Cover:
0.21 ± 0.01 square miles
(0.56 ± 0.04 km2)
(Rank: 3 of 29)
Highest Elevation (Head):
10,823 feet
(3,299 m)
Lowest Elevation (Terminus):
6,684 feet
(2,037 m)
Elevation Range:
4,139 feet
(1,262 m)
Length:
2.05 miles
(3.29 km)
Average Slope:
28°
Average Flow Direction (Flows towards):
Southwest (226°)
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CHANGE IN EXTENT, 1896-2015 (Beason, 2017):
| Units |
1896 |
1913 |
1971 |
1994 |
2009 |
2015 |
| Area, mi2 |
2.29 |
1.32 |
1.13 |
0.86 |
0.85 |
0.77 |
| Area, km2 |
5.93 |
3.43 |
2.92 |
2.23 |
2.21 |
2.00 |
Area change between periods
|
1913 |
1971 |
1994 |
2009 |
2015 |
| 1896 |
-0.96 mi2
(-2.50 km2) |
-1.16 mi2
(-3.00 km2) |
-1.43 mi2
(-3.69 km2) |
-1.44 mi2
(-3.72 km2) |
-1.52 mi2
(-3.92 km2) |
| 1913 |
-- |
-0.20 mi2
(-0.51 km2) |
-0.46 mi2
(-1.19 km2) |
-0.47 mi2
(-1.22 km2) |
-0.55 mi2
(-1.43 km2) |
| 1971 |
|
-- |
-0.27 mi2
(-0.69 km2) |
-0.28 mi2
(-0.72 km2) |
-0.36 mi2
(-0.92 km2) |
| 1994 |
|
-- |
-0.01 mi2
(-0.03 km2) |
-0.09 mi2
(-0.23 km2) |
| 2009 |
|
-- |
-0.08 mi2
(-0.20 km2) |
Percent change between periods
|
1913 |
1971 |
1994 |
2009 |
2015 |
| 1896 |
-42.2 % |
-50.7 % |
-62.3 % |
-62.8 % |
-66.2 % |
| 1913 |
-- |
-14.8 % |
-34.9 % |
-35.6 % |
-41.6 % |
| 1971 |
|
-- |
-23.6 % |
-24.5 % |
-31.5 % |
| 1994 |
|
-- |
-1.2 % |
-10.3 % |
| 2009 |
|
-- |
-9.3 % |
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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 |
0.1623 |
0.0939 |
0.0800 |
0.1025 |
0.0612 |
0.0604 |
0.0548 |
| Volume, km3 |
0.6766 |
0.3913 |
0.3336 |
0.4273 |
0.2549 |
0.2519 |
0.2285 |
* = 1981 was the only year that glacial volumes have been measured. See note below.
Basal Shear Stress (τ): 2,738.87 lbs/ft2
Volume change between periods
|
1913 |
1971 |
1981 |
1994 |
2009 |
2015 |
| 1896 |
-0.0685 mi3
(-0.2853 km3) |
-0.0823 mi3
(-0.3430 km3) |
-0.0598 mi3
(-0.2493 km3) |
-0.1012 mi3
(-0.4217 km3) |
-0.1019 mi3
(-0.4247 km3) |
-0.1075 mi3
(-0.4481 km3) |
| 1913 |
-- |
-0.0138 mi3
(-0.0577 km3) |
0.0086 mi3
(0.0360 km3) |
-0.0327 mi3
(-0.1364 km3) |
-0.0334 mi3
(-0.1394 km3) |
-0.0390 mi3
(-0.1627 km3) |
| 1971 |
|
-- |
0.0225 mi3
(0.0938 km3) |
-0.0189 mi3
(-0.0787 km3) |
-0.0196 mi3
(-0.0817 km3) |
-0.0252 mi3
(-0.1050 km3) |
| 1981 |
|
-- |
-0.0414 mi3
(-0.1724 km3) |
-0.0421 mi3
(-0.1755 km3) |
-0.0477 mi3
(-0.1988 km3) |
| 1994 |
|
-- |
-0.0007 mi3
(-0.0030 km3) |
-0.0063 mi3
(-0.0264 km3) |
| 2009 |
|
-- |
-0.0056 mi3
(-0.0233 km3) |
Percent change between periods
|
1913 |
1971 |
1981 |
1994 |
2009 |
2015 |
| 1896 |
-42.2 % |
-50.7 % |
-36.8 % |
-62.3 % |
-62.8 % |
-66.2 % |
| 1913 |
-- |
-14.8 % |
9.2 % |
-34.9 % |
-35.6 % |
-41.6 % |
| 1971 |
|
-- |
28.1 % |
-23.6 % |
-24.5 % |
-31.5 % |
| 1981 |
|
-- |
-40.4 % |
-41.1 % |
-46.5 % |
| 1994 |
|
-- |
-1.2 % |
-10.3 % |
| 2009 |
|
-- |
-9.3 % |
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