Base de données de recherche des TNO

Régions: Inuvialuit Settlement Region

étiquettes: physical sciences, permafrost, climate change, wedge ice

Objectif(s): To understand the rate of ground warming in permafrost due to climate change and to measure the changes in ground surface characteristics that are occurring as a result.

Description du projet: The objective of this research is to understand the rate of ground warming in permafrost due to climate change and to measure the changes in ground surface characteristics that are occurring as a result. In particular, the research team are interested in changes in ground temperature, in the depth of the active layer, and in subsidence of the ground. The team are also interested in measuring how quickly ice wedges are developing ponds and then melting out underneath, leading to degradation of tundra polygons. This project continues investigations in the western Arctic since 1987, and so an important objective is to keep some of the long-term records that we have as continuous series, so that the conclusions are based on firm evidence. The methods primarily consist of: 1) drilling holes in the ground to depths of up to 15 m with a water jet drill and installing thermistor cables with data loggers to measure ground temperatures; 2) installing bench marks for repeated surveys to determine how much the ground is settling or moving laterally; 3) monitoring the depth of thaw in the ground; 4) measuring snow depths and snow densities; 5) measuring lake-ice thicknesses; 6) measuring the temperature in ponds and other water bodies. When the team go to the field sites they make levelling surveys, retrieve data loggers and down load them, collect samples from soil pits, and drill holes to 3 or 4 m depth to collect samples from permafrost. Occasionally the research team make resistivity surveys of near-surface conditions. The team also pay close attention to changes in vegetation at the sites, and may make surveys of vegetation composition and abundance. At Illisarvik the team also place little shock loggers in the ground, which monitor mini earthquakes, because they are interested in detecting when ice wedges crack. In 2015 the team placed a wildlife camera at Illisarvik in front of a snow stake in order to see if we could monitor snow accumulation at the site. We hope to have assistants to travel with the team in winter from Inuvik to the outer delta, to collect data at Garry Island and Illisarvik. The research team will make an annual visit to the Hunters and Trappers Committee (HTC)to present the work both in the delta and on the Yukon North Slope and to discuss suggestions as to what the HTC might consider a priority for research on permafrost. The research team have a long-term monitoring program established with Aurora Research Institute (ARI) that involves technicians going to a site near Inuvik and another in the delta to collect ground temperatures. From time to time ARI asks the team to give presentations in schools and communities, and we have been happy to do that. In the next 5 years the team plan to visit a HTC meeting once each year to present the work, ask for comments, and discuss any concerns. The research team particularly hope to visit Aklavik because of research the team are involved with on the Yukon North Slope, in collaboration with Parks Canada, and on Herschel Island. The research team are also more than willing to answer any questions that arise from community members at other times. The team also make presentations in Yellowknife and Whitehorse. In 2019 the team will be offering a course for northerners on Transportation Engineering in Permafrost at the ARI, June 2 - 8. The fieldwork for this study will be conducted from April 27, 2019 to September 25, 2019.