NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region

Tags: physical sciences, geology, permafrost, sediment, remote sensing, ice, ground penetrating radar, geophysics, thermokarst, aggregate resources

Project Description: Sand, gravel and crushed stone are valuable geological resources, collectively known as aggregates. They are essential bed, foundation and building materials. The presence of massive ice in aggregate deposits results in a series of resource management problems, particularly for the oil industry and its contractors who rely on local granular deposits as building material. From an environmental perspective, there is the problem of thermokarst and terrain instability that results when these deposits are disturbed. From a development perspective, there are problems of extraction and overestimation of reserves. Project work is being undertaken together with the Department of Indian Affairs and Northern Development, and the Inuvialuit in preparation for a regional granular resource management plan for the Inuvialuit Settlement Region. In order to understand massive ice occurrence, the researchers will map ground ice sites in granular deposits using a variety of remote-sensing and geophysical tools. Collection of ice and sediment samples from two or more sites will also occur to understand the stratigraphic relationships between the aggregates and massive ground ice presence. In the winter, the research team will travel from base camp (either Inuvik or Tuktoyaktuk) by truck on existing winter roads or by helicopter to visit two or more study sites. If necessary, snowmobiles will be used to access sites located away from winter roads. Three types of passive, non-invasive surveys will be conducted, consisting of a high resolution GPS (Trimble System), a Ground Penetrating Radar (GPR) survey and a capacitive-coupled resistivity geophysical tool (Geomatics Ohm-Mapper system). Project work will also include the calibration of geophysical equipment to all types of massive ice, and will involve surveys on two sites, namely, Peninsula Point located 6km southwest of Tuktoyaktuk, and one of the smaller pingos located close to the winter road between Inuvik and Tuktoyaktuk. These sites will be accessed by foot or snowmobile with survey equipment in tow. Small ice and sediment (~1L) samples will be collected from natural massive ice exposures or by ice exposed as a result of granular extraction. The same work will be continued into the summer and fall, and study sites will be visited in these seasons by helicopter or boat. As with the winter fieldwork, no field camps will be established. To reduce the number of flights, the helicopter will remain in the field with the research team. All flights will adhere to recommendations by the Wildlife Management Advisory Council (NWT) for minimum flight altitudes. The study will be conducted from February 27 to March 31, and July 12 to November 15, 2006 at the following sites: North Richards Island Source 6C-1 (69° 39’ and between 134° 10’ and 134° 20), North Richards Island Source 4B-1 (69º 29’ 134º), Lousy Point (69º 15’ and between 134º 15’ and 134º 30’), Swimming Point (69º 6’ 134º 25’), Ya-Ya Lake Esker complex (69º 6’ and between 134º 35’ and 134º 50’), and Tuktoyaktuk granular sources 160/161, 155 and 177 (69º 25’ 132º 55’).