The tables and graphs presented below quantify the
surface velocity and surface elevation changes through time for all the
GPS-surveyed profiles on the Juneau Icefield. The velocities reported here are summer
velocities, usually observed over a time span of 4-5 weeks in July and August.
Winter velocities and mean annual velocities are not available. However,
research thus far indicates that winter movement does not vary appreciably from
the summer velocities. The tables and charts shown below contain only summary
data. Refer to the annual Survey
Reports for a complete record of survey activities, data collection, and
data reduction. The red numbers in the
table headers identify the profile locations on the map of the Juneau Icefield.
Other Related Data and Information
Map
of GPS Survey Profiles on the Juneau Icefield
Areal Extents of Glaciers in
the Southern Sector of the Juneau Icefield (Map)
Areal Extents of Glaciers in
the Southern Sector of the Juneau Icefield (Google Earth KMZ file)
Taku/Matthes/Llewellyn
Surface Velocities vs. Elevation
Comparative
Photographs of Temporal Snowcover Change on the Juneau Icefield
Taku Glacier Terminus Positions
from 2001 to 2007
| Profile 2 (Taku Glacier at Goat Ridge) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1994 | 56.5 | 93.0 | 82.6 | 11.6 | -11.9 | 2.2 | 804.965 | 2.479 |
Profile 3 (Lower Demorest Glacier) |
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Year |
Movement (cm/day) |
Height Change (cm/day) |
Surface Height at Epoch 0 (m) |
|||||
Minimum |
Maximum |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
|
1998 |
1.3 |
25.8 |
17.2 |
8.4 |
-5.1 |
1.1 |
1033.889 |
11.266 |
1999 |
0.9 |
26.0 |
17.6 |
8.3 |
-6.0 |
1.2 |
1034.099 |
11.273 |
Mean |
1.1 |
25.9 |
17.4 |
8.4 |
-5.6 |
1.2 |
1034.0 |
11.270 |
|
|
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| Profile 3a (Demorest Glacier east of C-9) | ||||||||
Year |
Movement (cm/day) |
Height Change (cm/day) |
Surface Height at Epoch 0 (m) |
|||||
Minimum |
Maximum |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
|
1998 |
0.3 |
20.1 |
10.3 |
7.4 |
-1.6* |
1.0 |
1354.124 |
17.071 |
1999 |
0.3 |
20.0 |
10.3 |
7.6 |
-5.9 |
0.9 |
1355.697 |
18.781 |
Mean |
0.3 |
20.1 |
10.3 |
7.5 |
-5.9 |
1.0 |
1354.9 |
17.926 |
* Apparent low value for mean height change is due to accumulation from snowstorm of August 7-10 |
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|
|
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| Profile 3b (Demorest Glacier at Floprock Peak) | ||||||||
Year |
Movement (cm/day) |
Height Change (cm/day) |
Surface Height at Epoch 0 (m) |
|||||
Minimum |
Maximum |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
|
1999 |
1.7 |
25.7 |
15.3 |
9.8 |
-5.2 |
2.2 |
1240.560 |
19.729 |
| Profile 4a (Icy Basin) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1995 | 0.5 | 3.8 | 1.7 | 1.1 | -3.8 | 0.8 | 1098.152 | 1.539 |
| Profile 4 (Taku Glacier at C-10) | ||||||||
Year |
Movement (cm/day) |
Height Change (cm/day) |
Surface Height at Epoch 0 (m) |
|||||
Minimum |
Maximum |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
|
1993 |
1.3 |
61.0 |
38.3 |
22.0 |
-5.1 |
1.4 |
1127.612 |
7.410 |
1994 |
1.3 |
60.5 |
34.9 |
23.5 |
-6.2 |
1.4 |
1129.592 |
8.818 |
1995 |
1.2 |
61.5 |
34.5 |
23.2 |
-5.1 |
0.9 |
1128.493 |
8.707 |
1996 |
0.9 |
60.1 |
32.9 |
22.8 |
-4.4 |
0.9 |
1127.479 |
8.815 |
1997 |
1.3 |
60.6 |
34.1 |
23.1 |
-6.1 |
1.6 |
1127.307 |
8.959 |
1998 |
0.5 |
59.9 |
33.6 |
22.9 |
-5.4 |
1.2 |
1126.075 |
8.981 |
1999 |
0.3 |
63.3 |
34.4 |
23.2 |
-4.8 |
1.6 |
1126.694 |
9.029 |
Mean |
1.0 |
61.0 |
34.7 |
23.0 |
-5.3 |
1.3 |
1127.6 |
8.674 |
|
|
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| Profile 5 (Lower Southwest Branch) | ||||||||
Year |
Movement (cm/day) |
Height Change (cm/day) |
Surface Height at Epoch 0 (m) |
|||||
Minimum |
Maximum |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
|
1994 |
1.0 |
9.4 |
6.6 |
2.6 |
-5.4 |
0.6 |
1073.038 |
7.829 |
1995 |
3.6 |
12.7 |
8.1 |
3.2 |
-5.6 |
1.1 |
1072.026 |
7.761 |
1997 |
0.7 |
10.0 |
7.0 |
2.9 |
-4.4 |
0.8 |
1070.772 |
7.800 |
1998 |
1.9 |
10.0 |
6.4 |
2.6 |
-5.2 |
0.8 |
1069.566 |
7.792 |
1999 |
1.4 |
10.5 |
6.4 |
3.1 |
-4.8 |
1.3 |
1070.057 |
7.888 |
Mean |
1.7 |
10.5 |
6.9 |
2.9 |
-5.1 |
0.9 |
1071.092 |
7.814 |
Profile 5 Surface Velocity and Elevation vs. Time  |
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Profile 6 (Taku NW Point to Echo Mountain) |
||||||||
Year |
Movement (cm/day) |
Height Change (cm/day) |
Surface Height at Epoch 0 (m) |
|||||
Minimum |
Maximum |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
|
1995 |
* |
* |
* |
* |
* |
* |
1330.275 |
5.286 |
1998 |
5.5 |
28.5 |
22.0 |
6.8 |
-4.0 |
1.0 |
1328.117 |
5.371 |
1999 |
5.1 |
28.6 |
21.9 |
6.9 |
-6.7 |
0.7 |
1329.064 |
5.361 |
Mean |
5.3 |
28.6 |
22.0 |
6.9 |
-5.4 |
0.9 |
1329.152 |
5.339 |
* Movement and height change data were not collected in 1995 |
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|
|
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| Profile 6a (Taku NW Point to Taku D) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1994 | 1.5 | 32.5 | 18.8 | 11.1 | -10.0 | 0.7 | 1280.379 | 4.795 |
| 1998 | 0.6 | 30.8 | 18.5 | 10.5 | -3.5 | 1.7 | 1276.199 | 4.715 |
| Mean | 1.1 | 31.7 | 18.7 | 10.8 | -6.7 | 1.2 | 1278.289 | 4.755 |
Profile 6a Surface Velocity and Elevation vs. Time  |
||||||||
| Profile 6b (Taku NW Point to Taku C) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1997 | 13.3 | 44.6 | 31.7 | 9.9 | -6.5 | 1.5 | 1254.798 | 12.337 |
| Profile 6c (Tricouni Peak to Glacier King) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1997 | 0.5 | 12.0 | 6.0 | 4.5 | -4.2 | 0.7 | 1470.366 | 14.980 |
| Profile 6d (Knowl Peak to Tricouni Peak) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1997 | 1.0 | 18.6 | 10.4 | 7.5 | -5.7 | 1.1 | 1437.192 | 11.293 |
Profile 7 (C-9 to Centurion Peak) |
||||||||
Year |
Movement (cm/day) |
Height Change (cm/day) |
Surface Height at Epoch 0 (m) |
|||||
Minimum |
Maximum |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
|
1996 |
0.9 |
33.5 |
19.4 |
13.5 |
-3.4 |
0.7 |
1428.033 |
14.667 |
1997 |
0.7 |
34.8 |
19.3 |
13.4 |
-7.6 |
1.3 |
1427.531 |
14.701 |
1998 |
1.3 |
32.1 |
19.0 |
12.8 |
-4.8* | 1.5* | 1425.883 |
14.594 |
1999 |
0.5 |
33.6 |
19.1 |
12.5 |
-8.2 |
0.7 |
1423.796 |
8.610 |
Mean |
0.9 |
33.5 |
19.2 |
13.1 |
-6.0 |
1.1 |
1426.311 |
13.143 |
| *
Snowfall of August 7-10, 1998 offset ablation between the two survey epochs.
Profile was shifted westward
by 2 flags in 1999. Surface height is not directly comparable with previous years |
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|
|
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Profile 7a (Taku C to Taku D) |
||||||||
Year |
Movement (cm/day) |
Height Change (cm/day) |
Surface Height at Epoch 0 (m) |
|||||
Minimum |
Maximum |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
Mean |
Standard Deviation |
|
1996 |
17.6 |
42.1 |
35.6 |
7.2 |
-4.9 |
0.6 |
1310.228 |
10.628 |
1997 |
17.9 |
43.1 |
35.7 |
7.2 |
-6.7 |
0.8 |
1309.714 |
10.563 |
1998 |
16.4 |
41.0 |
34.6 |
7.1 |
-5.8 |
1.0 |
1308.227 |
10.641 |
1999 |
18.2 |
42.3 |
35.6 |
7.2 |
-8.6 |
0.8 |
1308.824 |
10.796 |
Mean |
17.5 |
42.1 |
35.4 |
7.2 |
-6.5 |
0.8 |
1309.248 |
10.657 |
Profile 7a Surface Velocity and Elevation vs. Time  |
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| Profile 7b (The Citadel to Spirit Range) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1998 | 0.4 | 45.0 | 30.1 | 15.1 | -4.7 | 1.3 | 1566.830 | 14.092 |
| Profile 8 (Blizzard Peak to C-8) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1995 | 3.9 | 16.1 | 10.8 | 3.9 | -4.7 | 1.0 | 1811.718 | 18.505 |
| 1996 | 3.8 | 15.8 | 11.4 | 3.8 | -0.6* | 0.4* | 1810.776 | 18.422 |
| 1997 | 1.1 | 15.6 | 10.4 | 4.8 | -8.5 | 0.9 | 1809.773 | 18.243 |
| Mean | 2.9 | 15.8 | 10.9 | 4.2 | -4.6 | 0.8 | 1810.756 | 18.390 |
* Snowfall of August 8-9 offset ablation between 1996 survey epochs |
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Profile 8 Surface Velocity and Elevation vs. Time  |
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| Profile 9 (Upper Vaughan Lewis) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1995 | 11.5 | 36.2 | 26.2 | 10.6 | -3.9 | 1.1 | 1746.790 | 11.819 |
| 1996 | 5.7 | 12.9 | 9.9 | 2.3 | -0.5* | 0.5* | 1745.726 | 12.072 |
| 1997 | 6.9 | 12.4 | 9.7 | 1.8 | -14.0 | 2.2 | 1744.211 | 12.158 |
| Mean | 8.0 | 20.5 | 15.3 | 4.9 | -6.1 | 1.3 | 1745.576 | 12.016 |
* Snowfall of August 8-9 offset ablation between 1996 survey epochs. |
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Profile 9 Surface Velocity and Elevation vs. Time  |
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| Profile 9a (Matthes/Vaughan Lewis Divide) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1993 | * | * | * | * | * | * | 1776.676 | 14.022 |
| 1998 | * | * | * | * | * | * | 1772.572 | 13.881 |
| Mean | 1774.624 | 13.952 | ||||||
* Movement surveys were not conducted at this profile. Only
long-term height change is available. Data are for |
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Profile 9a Surface Velocity and Elevation vs. Time  |
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| Profile 10* - Flags 1 through 15 (Matthes/Llewellyn Longitudinal Profile) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1995 | 4.0 | 15.1 | 9.6 | 3.6 | -2.5 | 0.3 | 1831.964 | 30.152 |
* Flags 1-15 were set and surveyed in 1995. Flags 16-29 were set and surveyed in 1996. |
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| Profile 10* - Flags 16 through 29 (Matthes/Llewellyn Longitudinal Profile) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1996 | 4.7 | 7.2 | 6.1 | 0.7 | 0.9 | 0.5 | 1856.214 | 20.000 |
| * Flags 1-15 were set and surveyed in 1995. Flags 16-29 were set and surveyed in 1996. | ||||||||
| ** Snowstorm of August 4-8 offset ablation between 1996 survey epochs. | ||||||||
| Profile 10a (Matthes/Llewellyn Divide Grid) | ||||||||
| Year | Movement (cm/day) | Height Change (cm/day) | Surface Height at Epoch 0 (m) | |||||
| Minimum | Maximum | Mean | Standard Deviation | Mean | Standard Deviation | Mean | Standard Deviation | |
| 1997 | 1.3 | 8.9 | 5.8 | 2.1 | -8.9 | 2.1 | ||
