Yukon
Field research in Northern Canada (GEG4001)
The theme of the field course is geomorphological processes and recent environmental change in the Kluane Region, Yukon.
This is a six-credit course composed of the following units:
- Lacustrine-environment studies
(based at the Kluane Lake research station)
- Alluvial fan processes
(based at the Kluane Lake research station)
- Snow stratigraphy and snow-pack studies
(based at the Icefield Discovery Camp in the St. Elias Mountains)
You have to choose two units, which count for three credits each.
Lacustrine-environment studies
The marl lakes of the Kluane region are dominated by carbonate sedimentation produced in the water column as a result of CO2 exchange between the atmosphere and carbonate-rich water. The high carbonate content in the lake water is due to groundwater input from glacial deposits rich in dolomite. Our objective is to investigate environmental change over the last 1200 years by analyzing the sediments and macro-fossils in closed-basin marl lakes. The 1200- year level is defined by the White River volcanic ash stratigraphic marker. We measure sediment core stratigraphy, carbonate content and crystal form, organic content, and loess content; we also examine macro and micro fossils.
Alluvial fan processes
The alluvial fans along the west side of Kluane Lake were formed at the end of the Pleistocene. Through the Holocene, they have been modified strictly by flood events, particularly in the spring, which trigger most of the migration of the anastomosing (braiding) stream pattern. Although these processes on the alluvial fans today are of far lower magnitude than those during formation, they can still cause problems for infrastructure. When the streams were confined into fixed channels with culverts and bridges during the construction of the Alaska Highway, a new set of problems and maintenance requirements emerged. Hydrological measurements will be made during the snow melt spring freshet and will concentrate on one of the smaller streams. If the melt season is late, icings might remain in the culverts or channels and may also be studied.
Snow stratigraphy and snow-pack studies
This component of the field program takes place at the Icefield Discovery High-Altitude Camp. The camp is in a crevasse-free zone where up to fours meters of snow accumulate each year. Our goal is to study the snow pack's characteristics, with a focus on snow stratigraphy and basic snow chemistry. We excavate a snow pit on the ice divide and take detailed measurements of the snow density, structures and crystal characteristics. Below the previous summer surface, we take snow and ice samples with a CRREL ice corer. We also demonstrate glacier mass-balance measurement techniques.