Modelling suspended sediment discharge in a glaciated Arctic catchment–Lake Peters, Northeast Brooks Range, Alaska

• Published in: Hydrological Processes
• Main Authors: Thurston, Lorna Louise, Schiefer, Erik, McKay, Nicholas P., Kaufman, Darrell S.
• Other Authors: National Science Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Arctic; Endeavour; Brooks Range; glacier; Alaska
• Online Access: http://dx.doi.org/10.1002/hyp.13846; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhyp.13846; https://onlinelibrary.wiley.com/doi/pdf/10.1002/hyp.13846; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/hyp.13846; https://onlinelibrary.wiley.com/doi/am-pdf/10.1002/hyp.13846

Abstract Seasonal suspended sediment transfer in glaciated catchments is responsive to meteorological, geomorphological, and glacio‐fluvial conditions, and thus is a useful indicator of environmental system dynamics. Knowledge of multifaceted fluvial sediment‐transfer processes is limited in the Alaskan Arctic – a region sensitive to contemporary environmental change. For two glaciated sub‐catchments at Lake Peters, northeast Brooks Range, Alaska, we conducted a two‐year endeavour to monitor the hydrology and meteorology, and used the data to derive multiple‐regression models of suspended sediment load. Statistical selection of the best models shows that incorporating meteorological or temporal explanatory variables improves performances of turbidity‐ and discharge‐based sediment models. The resulting modelled specific suspended sediment yields to Lake Peters are: 33 (20–60) t km −2 yr −1 in 2015, and 79 (50–140) t km −2 yr −1 in 2016 (95% confidence band estimates). In contrast to previous studies in Arctic Alaska, fluvial suspended sediment transfer to Lake Peters was primarily influenced by rainfall, and secondarily influenced by temperature‐driven melt processes associated with clockwise diurnal hysteresis. Despite different sub‐catchment glacier coverage, specific yields were the same order of magnitude from the two primary inflows to Lake Peters, which are Carnivore Creek (128 km 2 10% glacier coverage) and Chamberlin Creek (8 km 2 23% glacier coverage). Seasonal to longer‐term sediment exhaustion and/or contrasting glacier dynamics may explain the lower than expected relative specific sediment yield from the more heavily glacierized Chamberlin Creek catchment. Absolute suspended sediment yield (t yr −1 ) from Carnivore Creek to Lake Peters was 27 times greater than from Chamberlin Creek, which we attribute to catchment size and sediment supply differences. Our results provide a foundational understanding of the current sediment transfer regime and are useful for predicting changes in fluvial sediment ...