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| Titel |
The equilibrium flow and mass balance of the Taku Glacier, Alaska 1950–2006 |
| VerfasserIn |
M. S. Pelto, M. M. Miller, G. W. Adema, M. J. Beedle, S. R. McGee, K. F. Sprenke, M. Lang |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 2, no. 2 ; Nr. 2, no. 2 (2008-11-13), S.147-157 |
| Datensatznummer |
250000531
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| Publikation (Nr.) |
 copernicus.org/tc-2-147-2008.pdf |
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| Zusammenfassung |
The Taku Glacier, Alaska has advanced 7.5 km since the late nineteenth
century, while all other primary outlet glaciers of the Juneau Icefield are
in retreat. The Juneau Icefield Research Program has completed field work on
the Taku Glacier annually since 1946. The collected observations of surface
mass balance, glacier velocity and glacier thickness at Profile IV 29 km
above the terminus and 4 km above the equilibrium line provide a means to
assess the equilibrium nature of the Taku Glacier. Annual velocity measured
and summer velocity measurements completed at a Profile IV from 1950–2006
indicate insignificant variations in velocity seasonally or from year to
year. The consistency of velocity over the 56-year period indicates that in
the vicinity of the equilibrium line, the flow of the Taku Glacier has been
in an equilibrium state.
Surface mass balance was positive from 1946–1988 averaging +0.42 m a−1.
This led to glacier thickening. From 1988–2006 an important change has
occurred and annual balance has been −0.14 m a−1, and the glacier
thickness has ceased increasing along Profile IV.
Field measurements of ice depth and surface velocity allow calculation of
the volume flux at Profile IV. Volume flux is then compared with the surface
balance flux from the region of the glacier above Profile IV, determined
annually in the field. Above Profile IV the observed mean surface flux from
1950–2006 is 5.50×108 m3 a−1 (±5%), while
the calculated volume flux range for the same period flowing through profile
IV is 5.00–5.47×108 m3 a−1. The mean surface flux has been
greater than the volume flux, which has led to slow thickening of the Taku
Glacier up to 1988. The thickening has not led to a change in the flow of
Taku Glacier at Profile IV. |
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