Hello guest! [ Log In ]
Glacier Info - Pyramid Glaciers

Switch Glacier:

Pyramid Glaciers
This glacier on Mount Rainier is triangular in shape and is located between the Kautz and Wilson Glaciers. F. E. Matthes wrote, "...it bears no name, but certainly deserves one. Merely in order to give it a handle for ready reference....the writer will speak of it here as Pyramid Glacier." (Reese, 2009)

STATISTICS AS OF 2015 (Beason, 2017):

Aerial Extent:
0.10 ± 0.01 square miles (0.26 ± 0.01 km2) (Rank: 26 of 29)

Debris Cover:
--No appreciable debris cover in 2015--

Highest Elevation (Head):
9,728 feet (2,965 m)

Lowest Elevation (Terminus):
7,455 feet (2,272 m)

Elevation Range:
2,273 feet (693 m)

Length:
0.77 miles (1.23 km)

Average Slope:
21°

Average Flow Direction (Flows towards):
South (188°)

CHANGE IN EXTENT, 1896-2015 (Beason, 2017):
Units 1896 1913 1971 1994 2009 2015
Area, mi2 1.06 0.54 0.27 0.25 0.15 0.10
Area, km2 2.75 1.39 0.71 0.64 0.38 0.26

Area change between periods
1913 1971 1994 2009 2015
1896 -0.52 mi2
(-1.35 km2)
-0.79 mi2
(-2.04 km2)
-0.81 mi2
(-2.10 km2)
-0.91 mi2
(-2.37 km2)
-0.96 mi2
(-2.48 km2)
1913 -- -0.26 mi2
(-0.68 km2)
-0.29 mi2
(-0.75 km2)
-0.39 mi2
(-1.02 km2)
-0.44 mi2
(-1.13 km2)
1971 -- -0.02 mi2
(-0.06 km2)
-0.13 mi2
(-0.33 km2)
-0.17 mi2
(-0.45 km2)
1994 -- -0.10 mi2
(-0.27 km2)
-0.15 mi2
(-0.38 km2)
2009 -- -0.04 mi2
(-0.12 km2)

Percent change between periods
1913 1971 1994 2009 2015
1896 -49.2 % -74.2 % -76.5 % -86.2 % -90.5 %
1913 -- -49.1 % -53.7 % -72.8 % -81.2 %
1971 -- -9.1 % -46.6 % -63.0 %
1994 -- -41.3 % -59.3 %
2009 -- -30.7 %

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 0.0535 0.0250 0.0117 0.0089 0.0105 0.0058 0.0038
Volume, km3 0.2230 0.1041 0.0487 0.0372 0.0438 0.0240 0.0159
* = 1981 was the only year that glacial volumes have been measured. See note below.

Basal Shear Stress (τ): 2,193.17 lbs/ft2

Volume change between periods
1913 1971 1981 1994 2009 2015
1896 -0.0285 mi3
(-0.1190 km3)
-0.0418 mi3
(-0.1743 km3)
-0.0446 mi3
(-0.1859 km3)
-0.0430 mi3
(-0.1793 km3)
-0.0477 mi3
(-0.1990 km3)
-0.0497 mi3
(-0.2071 km3)
1913 -- -0.0133 mi3
(-0.0554 km3)
-0.0161 mi3
(-0.0669 km3)
-0.0145 mi3
(-0.0603 km3)
-0.0192 mi3
(-0.0800 km3)
-0.0211 mi3
(-0.0882 km3)
1971 -- -0.0028 mi3
(-0.0115 km3)
-0.0012 mi3
(-0.0050 km3)
-0.0059 mi3
(-0.0247 km3)
-0.0079 mi3
(-0.0328 km3)
1981 -- 0.0016 mi3
(0.0066 km3)
-0.0031 mi3
(-0.0131 km3)
-0.0051 mi3
(-0.0212 km3)
1994 -- -0.0047 mi3
(-0.0197 km3)
-0.0067 mi3
(-0.0278 km3)
2009 -- -0.0020 mi3
(-0.0081 km3)

Percent change between periods
1913 1971 1981 1994 2009 2015
1896 -53.3 % -78.2 % -83.3 % -80.4 % -89.2 % -92.9 %
1913 -- -53.2 % -64.3 % -58.0 % -76.9 % -84.7 %
1971 -- -23.7 % -10.2 % -50.6 % -67.3 %
1981 -- 17.8 % -35.3 % -57.2 %
1994 -- -45.0 % -63.6 %
2009 -- -33.8 %

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!

NOTES:


Data References: Beason, 2017, George and Beason, 2017, Reese, 2009, and Driedger and Kennard, 1986