Suspended Sediment Transport Relationships For Four Alaskan Glacier Streams PDF Download

"Gravimetric sampling of daily suspended sediment of melt water, collected at 2 hour intervals during the 1997-2000 ablation seasons for melt streams and selective vents draining the terminus of the Matanuska Glacier, Alaska, was determined in order to assess the temporal variation of sediment flux with discharge and the annual sediment yield. The seasonal pattern of suspended sediment transport in melt water streams shows large sediment pulses early in the ablation season, followed by more subdued variations in sediment flux later in the ablation season. The pulses likely result from the rapid expansion of the developing subglacial drainage system into areas of the glacier subsole where fine products of glacial abrasion are stored. The suspended sediment record also shows that sediment pulses at different vents are generally not in phase and may be due to sudden localized expansion of the subglacial drainage system. Assuming a bed load contribution of approximately 35%, the total sediment flux for the Matanuska Glacier during the 1997-2000 melt seasons ranged from 2.68E+03 tonnes km−2 for the 2000 melt season to 5.58E+O3 tonnes km−2 for the 1999 melt season. These fluxes represent a range of subsequent erosion rates of 1.01 mm yr−1 for the 2000 melt season to 2.08 mm yr−1 for the 1999 melt season. These rates are substantially less than rates published for the large glaciers of southeastern Alaska but are comparable to rates published for glaciers in the European Alps and central Asia"--Leaf ii