GLACIAL HYDROLOGY

Most glacier melt water is routed from the surface via crevasses, moulins and other glacial fissures into englaical and subglacial stream systems. The glacial melt remaining on the surface travels via supraglacial streams. A better understanding of supraglacial hydrology is needed to understand the controls on velocity. Dye tests were completed on 30 to 40 meter sections of supraglacial streams. Slope distance was measured with a laser ranger, and slope determined with an inclinometer. Three specific travel times of the dye along the study stretch were recorded: initial arrival, peak flow and end flow. Stream channel type was also categorized based on visual analysis into the following categories: englacial, sinusoidal, semi-sinusoidal, straight, and immature. Plunge pools were also noted in streams, as a subset. The relationship between stream channel type and velocity was the primary objective; data was plotted comparing velocity to both channel type and slope. Examining velocity while grouping data by stream channel type presented more questions than answers. The initial assumption was that the more mature the stream channel the less efficient the flow mechanisms, thus a slower velocity. By plotting stream age versus velocity, a negative relationship is evident but not particularly strong or significant. Stream age is estimated by assigning an age parameter to each stream channel type. One, is the youngest being an immature channel and seven, the englacial stream, is the oldest. This study contained data only for the 2009 summer field season. The slope relationship demonstrated no connection between a steep gradient and fast flow. It appears that a steep slope influences a stream to become more sinusoidal, though this statement will require significant further observation. In future seasons we will monitor more streams and gather additional data on sinuosity and bedforms, allowing us to better constrain the relationship.