Hydrological and Meteorological Observations at Lake Tuborg,
Ellesmere Island, Nunavut, Canada
Carsten Braun, Douglas R. Hardy, and Raymond S. Bradley
Climate System Research Center, Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, U.S.A.
Michael J. Retelle
Department of Geology, Bates College, Lewiston, Maine 04240, U.S.A.
Abstract
We conducted hydrological and meteorological observations at Lake Tuborg, Ellesmere Island, Nunavut,
Canada in 1995 to investigate contemporary water and sediment transport processes. Here we describe a
new environmental data set for the High Arctic, where such data are scarce. The studied watershed
(~460 km2) ranges in elevation between 63 and ~1900 m asl and is 88% covered by a lobe of the Agassiz Ice Cap.
Streamflow and sediment transport were strongly associated with snowmelt runoff, whereas the direct influence
of summer precipitation events was negligible. Snowmelt was primarily controlled by synoptic-scale climatic
processes. Two high-magnitude pulses of meltwater and slush contributed a significant portion of the measured
suspended sediment load to Lake Tuborg. Such events may be associated each year with snowmelt along the Agassiz
Ice Cap margin. Additional years of data collection are needed to define the annual and inter-annual variability
of the sediment delivery system, particularly with respect to the relative importance of summer rainfall events.
Runoff and sediment transport to Lake Tuborg are very likely to increase under climatic warming conditions.
Streamflow and Suspended Sediment Transfer to Lake Sophia,
Cornwallis Island, Nunavut, Canada
Carsten Braun, Douglas R. Hardy, and Raymond S. Bradley
Climate System Research Center, Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, U.S.A.
Michael J. Retelle
Department of Geology, Bates College, Lewiston, Maine 04240, U.S.A.
Abstract
To ascertain the climatic controls on sediment transport to Lake Sophia, Cornwallis Island, Nunavut, Canada,
we made detailed hydrological and meteorological measurements in the Sophia River watershed through the 1994 melt
season. Streamflow and suspended sediment transport are limited, on an annual time scale, by the supply of snow
and sediment in the watershed. Suspended sediment yield from the watershed was only 0.46 t km-2, which is lower
than any previously published yield for a stream in the High Arctic. Snowmelt runoff accounted for 88% of the annual
suspended sediment load, whereas 6% and 9% were transported in response to a slushflow event and summer rainfall,
respectively. These measurements provide no direct evidence that modern-day sediment delivery to Lake Sophia is
related to fluctuations in air temperature, which has implications for the paleoenvironmental signal preserved
in Lake Sophia's laminated sediments. We suggest that on-site sediment transport studies are necessary to
establish the relationships among geology, geography, climate, and hydrology unique to each watershed-lake
system and need to be an integral part of any calibration attempt. Additional years of data are needed
however to define the inter-annual variability of streamflow and sediment transport in response to climate.
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