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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:
0.025098
| Units |
1896 |
1913 |
1971 |
1994 |
2009 |
2015 |
2021 |
| Volume, mi3 |
0.1085 |
0.1450 |
0.1344 |
0.1404 |
0.1045 |
0.1220 |
0.1167 |
| Volume, km3 |
0.4521 |
0.6045 |
0.5601 |
0.5851 |
0.4357 |
0.5087 |
0.4865 |
Volume Change Between Periods
|
1913 |
1971 |
1994 |
2009 |
2015 |
2021 |
| 1896 | 0.037 mi3
(0.152 km3) | 0.026 mi3
(0.108 km3) | 0.032 mi3
(0.133 km3) | -0.004 mi3
(-0.016 km3) | 0.014 mi3
(0.057 km3) | 0.008 mi3
(0.034 km3) |
|---|
| 1913 | -- | -0.011 mi3
(-0.044 km3) | -0.005 mi3
(-0.019 km3) | -0.040 mi3
(-0.169 km3) | -0.023 mi3
(-0.096 km3) | -0.028 mi3
(-0.118 km3) |
|---|
| 1971 | | -- | 0.006 mi3
(0.025 km3) | -0.030 mi3
(-0.124 km3) | -0.012 mi3
(-0.051 km3) | -0.018 mi3
(-0.074 km3) |
|---|
| 1994 | | | -- | -0.036 mi3
(-0.149 km3) | -0.018 mi3
(-0.076 km3) | -0.024 mi3
(-0.099 km3) |
|---|
| 2009 | | | | -- | 0.018 mi3
(0.073 km3) | 0.012 mi3
(0.051 km3) |
|---|
| 2015 | | | | | -- | -0.005 mi3
(-0.022 km3) |
|---|
Percent Change Between Periods
|
1913 |
1971 |
1994 |
2009 |
2015 |
2021 |
| 1896 | 33.70% | 23.89% | 29.42% | -3.63% | 12.52% | 7.61% |
|---|
| 1913 | -- | -7.34% | -3.21% | -27.92% | -15.84% | -19.52% |
|---|
| 1971 | | -- | 4.46% | -22.22% | -9.18% | -13.15% |
|---|
| 1994 | | | -- | -25.54% | -13.06% | -16.85% |
|---|
| 2009 | | | | -- | 16.76% | 11.66% |
|---|
| 2015 | | | | | -- | -4.37% |
|---|
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 Winthrop Glacier is 0.025098 (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 Winthrop Glacier in 2021, you can find the following individual volumes:
Back-calculated Dreidger and Kennard (1986) Method: 0.1177 mi3 (0.4905 km3).
Back-calculated Nylen (2001) Method: 0.1157 mi3 (0.4825 km3).
Average of the two (above equation and values listed for 2021 here): 0.1167 mi3 (0.4865 km3).
Official volume estimate listed above, with error: 0.1167 ± 0.0408 mi3 (0.4865 ± 0.1703 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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