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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:
0.02354
| Units |
1896 |
1913 |
1971 |
1994 |
2009 |
2015 |
2021 |
| Volume, mi3 |
0.1759 |
0.1217 |
0.0945 |
0.0888 |
0.0805 |
0.0807 |
0.0750 |
| Volume, km3 |
0.7333 |
0.5075 |
0.3938 |
0.3701 |
0.3355 |
0.3362 |
0.3125 |
Volume Change Between Periods
|
1913 |
1971 |
1994 |
2009 |
2015 |
2021 |
| 1896 | -0.054 mi3
(-0.226 km3) | -0.081 mi3
(-0.339 km3) | -0.087 mi3
(-0.363 km3) | -0.095 mi3
(-0.398 km3) | -0.095 mi3
(-0.397 km3) | -0.101 mi3
(-0.421 km3) |
|---|
| 1913 | -- | -0.027 mi3
(-0.114 km3) | -0.033 mi3
(-0.137 km3) | -0.041 mi3
(-0.172 km3) | -0.041 mi3
(-0.171 km3) | -0.047 mi3
(-0.195 km3) |
|---|
| 1971 | | -- | -0.006 mi3
(-0.024 km3) | -0.014 mi3
(-0.058 km3) | -0.014 mi3
(-0.058 km3) | -0.020 mi3
(-0.081 km3) |
|---|
| 1994 | | | -- | -0.008 mi3
(-0.035 km3) | -0.008 mi3
(-0.034 km3) | -0.014 mi3
(-0.058 km3) |
|---|
| 2009 | | | | -- | 0.000 mi3
(0.001 km3) | -0.006 mi3
(-0.023 km3) |
|---|
| 2015 | | | | | -- | -0.006 mi3
(-0.024 km3) |
|---|
Percent Change Between Periods
|
1913 |
1971 |
1994 |
2009 |
2015 |
2021 |
| 1896 | -30.80% | -46.30% | -49.53% | -54.24% | -54.15% | -57.39% |
|---|
| 1913 | -- | -22.39% | -27.07% | -33.88% | -33.74% | -38.42% |
|---|
| 1971 | | -- | -6.02% | -14.80% | -14.62% | -20.65% |
|---|
| 1994 | | | -- | -9.34% | -9.15% | -15.57% |
|---|
| 2009 | | | | -- | 0.21% | -6.87% |
|---|
| 2015 | | | | | -- | -7.07% |
|---|
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 Tahoma Glacier is 0.02354 (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 Tahoma Glacier in 2021, you can find the following individual volumes:
Back-calculated Dreidger and Kennard (1986) Method: 0.0730 mi3 (0.3043 km3).
Back-calculated Nylen (2001) Method: 0.0769 mi3 (0.3206 km3).
Average of the two (above equation and values listed for 2021 here): 0.0750 mi3 (0.3125 km3).
Official volume estimate listed above, with error: 0.0750 ± 0.0262 mi3 (0.3125 ± 0.1094 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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