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ESTIMATED CHANGE IN VOLUME, 1896-2021 (Beason et al., 2023):
PLEASE see important notes about this, below...
Glacier-specific Scaling Parameter, c:
0.026953
| Units |
1896 |
1913 |
1971 |
1994 |
2009 |
2015 |
2021 |
| Volume, mi3 |
0.1473 |
0.0829 |
0.0742 |
0.0772 |
0.0730 |
0.0447 |
0.0434 |
| Volume, km3 |
0.6139 |
0.3456 |
0.3091 |
0.3219 |
0.3043 |
0.1862 |
0.1808 |
Volume Change Between Periods
|
1913 |
1971 |
1994 |
2009 |
2015 |
2021 |
| 1896 | -0.064 mi3
(-0.268 km3) | -0.073 mi3
(-0.305 km3) | -0.070 mi3
(-0.292 km3) | -0.074 mi3
(-0.310 km3) | -0.103 mi3
(-0.428 km3) | -0.104 mi3
(-0.433 km3) |
|---|
| 1913 | -- | -0.009 mi3
(-0.036 km3) | -0.006 mi3
(-0.024 km3) | -0.010 mi3
(-0.041 km3) | -0.038 mi3
(-0.159 km3) | -0.040 mi3
(-0.165 km3) |
|---|
| 1971 | | -- | 0.003 mi3
(0.013 km3) | -0.001 mi3
(-0.005 km3) | -0.029 mi3
(-0.123 km3) | -0.031 mi3
(-0.128 km3) |
|---|
| 1994 | | | -- | -0.004 mi3
(-0.018 km3) | -0.033 mi3
(-0.136 km3) | -0.034 mi3
(-0.141 km3) |
|---|
| 2009 | | | | -- | -0.028 mi3
(-0.118 km3) | -0.030 mi3
(-0.124 km3) |
|---|
| 2015 | | | | | -- | -0.001 mi3
(-0.005 km3) |
|---|
Percent Change Between Periods
|
1913 |
1971 |
1994 |
2009 |
2015 |
2021 |
| 1896 | -43.70% | -49.64% | -47.57% | -50.42% | -69.67% | -70.55% |
|---|
| 1913 | -- | -10.56% | -6.87% | -11.94% | -46.13% | -47.69% |
|---|
| 1971 | | -- | 4.12% | -1.55% | -39.77% | -41.51% |
|---|
| 1994 | | | -- | -5.44% | -42.15% | -43.83% |
|---|
| 2009 | | | | -- | -38.82% | -40.59% |
|---|
| 2015 | | | | | -- | -2.90% |
|---|
Important comments about the calculation of volume shown here
The calculation of glacial volume shown on this page is based on an analysis of two methods used at Mount Rainier in the past (Driedger and Kennard [1986]; and Nylen [2001]) as well as the most recent literature review for glacier area-volume scaling (Please review Beason et al. [2023] for an in-depth discussion about this issue). It should be noted that simply converting area to volume with an equation is extremely difficult and the values presented here have extremely large error margins (likely ± 35% or more). With that in mind, the values presented here should give you an estimate of the glacial volume and change in volume over time. Please use these data very carefully with those caveats.
The calcuation of the volume is as follows:
\[V_i = {(c_iA_i^{1.375}) + (c_nA_i^{1.36}) \over 2}\]
Where:
\(V_i\) = Average volume for the glacier in question (km3);
\(c_i\) = The glacier-specific scaling parameter (back-calculated from glacier area and volume in 1971 in Driedger and Kennard (1986); Method described in Beason et al. (2023). The value for the Nisqually Glacier is 0.026953 (this is also listed above the volume graph);
\(c_n\) = The back-calculated scaling parameter from Nylen (2001) of 0.0255; and
\(A_i\) = The measured volume of the glacier in question (km2).
This is essentially an average of the back-calculated Dreidger and Kennard (1986) and Nylen (2001) methods (D&K is in the first parenthesis; Nylen in the second). For example, for the Nisqually Glacier in 2021, you can find the following individual volumes:
Back-calculated Dreidger and Kennard (1986) Method: 0.0450 mi3 (0.1877 km3).
Back-calculated Nylen (2001) Method: 0.0417 mi3 (0.1739 km3).
Average of the two (above equation and values listed for 2021 here): 0.0434 mi3 (0.1808 km3).
Official volume estimate listed above, with error: 0.0434 ± 0.0152 mi3 (0.1808 ± 0.0633 km3).
As you can see, the D&K method tends to produce higher values and Nylen produces lower values; the average of these two methods probably estimates the glacial volume. Until further research is done in this area and we can develop a better method or equation to determine volumes, this is the method we are using to determine glacial volumes. For more information about this method, please read the methods section of Beason et al. (2023).
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