Hello guest! [ Log In ]
Glacier Info - Flett Glacier

Switch Glacier:

Flett Glacier
This small permanent snow field is near Ptarmigan Ridge on the northwestern slope of Mount Rainier. Professor John B. Flett of the Tacoma Public Schools was for many years one of the most enthusiastic explorers of the mountain area and had the honor of naming a number of locations on the mountain. John B. Flett was born in the Orkney Islands in 1859 and come to the United States in 1874. He graduated in 1885 from Hamilton College with first honors in chemistry, and until 1892 when he came to Tacoma, he was teacher and principal of schools in New York State. He continued this career in Tacoma but also began his botanizing work and in 1896 he went into the Olympics with a party of gold hunters. The next season he went alone, and July 20, 1897, he made his first discovery of a new species, a large and beautiful violet with kidney-shaped leaves. He was a park ranger between 1913 and 1921. (Reese, 2009)

STATISTICS AS OF 2015 (Beason, 2017):

Aerial Extent:
0.16 ± 0.01 square miles (0.41 ± 0.02 km2) (Rank: 25 of 29)

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

Highest Elevation (Head):
7,976 feet (2,431 m)

Lowest Elevation (Terminus):
6,940 feet (2,115 m)

Elevation Range:
1,036 feet (316 m)

Length:
0.46 miles (0.73 km)

Average Slope:
21°

Average Flow Direction (Flows towards):
N (352°)

CHANGE IN EXTENT, 1896-2015 (Beason, 2017):
Units 1896 1913 1971 1994 2009 2015
Area, mi2 -- 0.28 0.22 0.24 0.22 0.16
Area, km2 -- 0.74 0.58 0.62 0.58 0.41

Area change between periods
1913 1971 1994 2009 2015
1896 0.28 mi2
(0.74 km2)
0.22 mi2
(0.58 km2)
0.24 mi2
(0.62 km2)
0.23 mi2
(0.58 km2)
0.16 mi2
(0.41 km2)
1913 -- -0.06 mi2
(-0.16 km2)
-0.05 mi2
(-0.12 km2)
-0.06 mi2
(-0.15 km2)
-0.13 mi2
(-0.33 km2)
1971 -- 0.02 mi2
(0.04 km2)
0.00 mi2
(0.01 km2)
-0.07 mi2
(-0.17 km2)
1994 -- -0.01 mi2
(-0.03 km2)
-0.08 mi2
(-0.21 km2)
2009 -- -0.07 mi2
(-0.18 km2)

Percent change between periods
1913 1971 1994 2009 2015
1896 -73,690.0 % -57,688.5 % -61,577.4 % -58,244.3 % -40,624.5 %
1913 -- -21.7 % -16.5 % -21.0 % -44.9 %
1971 -- 6.8 % 1.0 % -29.6 %
1994 -- -5.4 % -34.1 %
2009 -- -30.3 %

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 -- 0.0122 0.0093 0.0045 0.0100 0.0094 0.0062
Volume, km3 -- 0.0508 0.0386 0.0186 0.0415 0.0390 0.0260
* = 1981 was the only year that glacial volumes have been measured. See note below.

Basal Shear Stress (τ): 2,297.74 lbs/ft2

Volume change between periods
1913 1971 1981 1994 2009 2015
1896 0.0122 mi3
(0.0508 km3)
0.0093 mi3
(0.0386 km3)
0.0045 mi3
(0.0186 km3)
0.0100 mi3
(0.0415 km3)
0.0094 mi3
(0.0390 km3)
0.0062 mi3
(0.0260 km3)
1913 -- -0.0029 mi3
(-0.0122 km3)
-0.0077 mi3
(-0.0322 km3)
-0.0022 mi3
(-0.0093 km3)
-0.0028 mi3
(-0.0118 km3)
-0.0060 mi3
(-0.0248 km3)
1971 -- -0.0048 mi3
(-0.0200 km3)
0.0007 mi3
(0.0029 km3)
0.0001 mi3
(0.0004 km3)
-0.0030 mi3
(-0.0126 km3)
1981 -- 0.0055 mi3
(0.0229 km3)
0.0049 mi3
(0.0204 km3)
0.0018 mi3
(0.0074 km3)
1994 -- -0.0006 mi3
(-0.0025 km3)
-0.0037 mi3
(-0.0155 km3)
2009 -- -0.0031 mi3
(-0.0130 km3)

Percent change between periods
1913 1971 1981 1994 2009 2015
1896 -5,080,700.9 % -3,856,906.3 % -1,858,100.0 % -4,150,855.9 % -3,898,770.5 % -2,598,371.9 %
1913 -- -24.1 % -63.4 % -18.3 % -23.3 % -48.9 %
1971 -- -51.8 % 7.6 % 1.1 % -32.6 %
1981 -- 123.4 % 109.8 % 39.8 %
1994 -- -6.1 % -37.4 %
2009 -- -33.4 %

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:
Area was not measured for this glacier in 1896

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