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 research team are also interested in measuring how quickly ice wedges are developing ponds and then melting out underneath, leading to degradation of tundra polygons. The 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 our 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; and, 6) measuring the temperature in ponds and other water bodies. When the team go to the field sites levelling surveys, data loggers are retrieved and downloaded, samples from soil pits are collected, and holes are drilled to 3 or 4 m depth to collect samples from permafrost. Occasionally the research team make resistivity surveys of near-surface conditions. The teamalso pay close attention to changes in vegetation at the sites, and surveys are taken of vegetation composition and abundance. At Illisarvik the research team also place little shock loggers in the ground, which monitor mini earthquakes, because the team are interested in detecting when ice wedges crack. In 2015 a wildlife camera was placed at Illisarvik in front of a snow stake in order to see if the team could monitor snow accumulation at the site. The research team will make an annual visit to a 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 team have a long-term monitoring program established with the Aurora Research Institute (ARI) that involves their technicians going to a site near Inuvik and another in the delta to collect ground temperatures. From time to time ARI invites the team to give presentations in Inuvik and in schools in the region. The research team have often taken summer students from the ARI to the field sites. In the next 5 years the research team plan to visit a HTC meeting once each year to present the work, ask for comments, and discuss any concerns. The team particularly hope to visit Aklavik because of research they 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 fieldwork for this study will be conducted from April 9, 2017 to August 27, 2017.