Geometry, mass balance and thinning at Eklutna Glacier, Alaska: an altitude-mass-balance feedback with implications for water resources
| Autor: | Daniel McGrath, Jason Geck, Evan E. Thoms, Michael G. Loso, L. Sass |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Hypsometry
Hydrology geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Firn Accumulation zone Elevation Glacier 010502 geochemistry & geophysics 01 natural sciences Glacier mass balance Altitude Deglaciation Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Journal of Glaciology. 63:343-354 |
| ISSN: | 1727-5652 0022-1430 |
| Popis: | We analyzed glacier surface elevations (1957, 2010 and 2015) and surface mass-balance measurements (2008–2015) on the 30 km2Eklutna Glacier, in the Chugach Mountains of southcentral Alaska. The geodetic mass balances from 1957 to 2010 and 2010 to 2015 are −0.52 ± 0.46 and −0.74 ± 0.10 m w.e. a−1, respectively. The glaciological mass balance of −0.73 m w.e. a−1from 2010 to 2015 is indistinguishable from the geodetic value. Even after accounting for loss of firn in the accumulation zone, we found most of the mass loss over both time periods was from a broad, low-slope basin that includes much of the accumulation zone of the main branch. Ice-equivalent surface elevation changes in the basin were −1.0 ± 0.8 m a−1from 1957 to 2010, and −0.6 ± 0.1 m a−1from 2010 to 2015, shifting the glacier hypsometry downward and resulting in more negative mass balances: an altitude-mass-balance feedback. Net mass loss from Eklutna Glacier accounts for 7 ± 1% of the average inflow to Eklutna Reservoir, which is entirely used for water and power by Anchorage, Alaska's largest city. If the altitude-mass-balance feedback continues, this ‘deglaciation discharge dividend’ is likely to increase over the short-term before it eventually decreases due to diminishing glacier area. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|