HYDROLOGIC PROCESSES INFLUENCING STREAMFLOW VARIATION IN FRYXELL BASIN, ANTARCTICA
In the McMurdo Dry Valleys, glacial meltwater streams are a critical linkage between the glaciers and the lakes in the valley bottoms. This paper analyzes the physiographic characteristics and six years of discharge data from five streams in order to better characterize the dynamic inputs into Lake...
| Main Authors: | , , , , |
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| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.615.3680 http://warnercnr.colostate.edu/~leemac/publications/HydrologicProcessesInfluencingStreamflowVariationinFryxellBasinAntartica.pdf |
| Summary: | In the McMurdo Dry Valleys, glacial meltwater streams are a critical linkage between the glaciers and the lakes in the valley bottoms. This paper analyzes the physiographic characteristics and six years of discharge data from five streams in order to better characterize the dynamic inputs into Lake Fryxell, a closed basin in Taylor Valley. These feeder streams typically flow only for six to eight weeks during the summer, and streamflow is highly variable on an interannual as well as daily basis. During low flow years, the shorter streams contributed a higher proportion of the total annual inflow into the lake; this pattern may reflect the greater losses to wetting the hyporheic zone. Comparisons of the period of direct sun on the glacier faces with the time of peak flow suggested that solar position and melt from the glacier faces are the dominant controls on the diurnal fluctuations in streamflow. An analysis of streamflow recession showed considerable variability between streams and in some cases, over time. For example, recession coefficients for Canada Stream, a short stream with an incised channel, were fairly invariant with streamflow. In contrast, the recession coefficients for Lost Seal Stream, an unconfined, low gradient stream, increased significantly with increasing discharge. These observations lead to hypotheses for the control of streamflow dynamics in the McMurdo Dry Valleys by climate, solar position, and geomotphic factors. |
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