NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: physical sciences, sediment, bedrock, remote sensing, biogeochemical processes

Objective(s): To integrate field observations, geochemical techniques, and historical remote sensing analysis to quantify the rates and processes by which sediment is generated from bedrock and transported downslope via hillslope and river processes under a changing climate.

Project Description: This licence has been issued for the scientific research application No.5411. or this latest phase of research, the research team propose to integrate field observations, geochemical techniques, and historical remote sensing analysis to quantify the rates and processes by which sediment is generated from bedrock and transported downslope via hillslope and river processes under a changing climate. The major objectives are to: (1) conduct fieldwork to determine the processes by which bedrock is broken down into transportable sediment and how that sediment moves across the landscape; (2) perform laboratory analyses on samples collected in the field to quantify rates of sediment production and transport over decadal to millennial scales; (3) use remote sensing techniques, historical imagery, and Gwich’in traditional knowledge to extend local findings to the broader region over the last several decades; and (4) use these data to calibrate sediment production and transport models so that the team can predict future landscape response to warming. The alluvial fans the research team are proposing to study are on Gwich’in private lands. The team are requesting permission to access and camp on/near the fans over the course of three separate field seasons (between 2022–2026), ideally with the assistance of wildlife monitors and occasional community participants from Aklavik (and/or Inuvik). In case the team have issues accessing the field area due to restrictions related to the COVID-19 pandemic, the team are requesting to have a five-year permit (2022–2026), just in case one of these years the team cannot do fieldwork. The three proposed field campaigns would span ~3–4 weeks during the summer months (either late May–June or in July–August) and would include 4–6 scientists. The research team would like to study two alluvial fans and their catchment areas from three or four separate camps. The first camp location would be at the base of the Black Mountain fan along the Husky Channel, which is the same site in 2019 (67.965423°, -135.339320°). In addition, the team would like to establish a helicopter-based camp within the higher catchment of Black Mountain (67.968743°, -135.432826°). The third proposed camp location has yet to be clearly identified, but it will probably be located near the snowmobile trail that accesses Red Mountain from the Husky Channel (68.079921°, -135.383661°). If that does not look good, the team may try a higher camp within the upper catchment of Red Mountain by using helicopter access (68.096504°, -135.431797°). The research team propose to establish two types of camps: 1) boat-based and 2) helicopter-based. Both camps will be similar in nature, the only difference being the transportation to/from the field sites. The camps will have small footprints and consist of personal tents, a group cook/storage tent, and scientific equipment. The team will not tamper with vegetation, will bury all human waste, and will remove all trash and waste upon completion of the field work. All meals will be prepared on small propane or white-gas stoves and will only need a small amount of gasoline to temporarily power a generator for our scientific instruments. Once these camps are established, the team will carry out all fieldwork on foot from these respective locations. The research team propose to perform the following research activities over the course of the study: Seasonal Surveying/Monitoring A. Walk up and down the fans to make general observations about sediment grain sizes, where the research team observe channels and if there are sediment deposits in those channels. In addition, the team will perform detailed observations of the catchment headwall regions to understand the nature of the bedrock fracture patterns and their potential for the creation of landslides. B. Annual unmanned aerial vehicle (UAV), or drone, mapping of the Black and Red Mountain fans. This will entail ~1-2-day mapping campaigns using quadcopter or fixed-wing UAVs depending on the nature of take-off/landing options. C. Annual use a terrestrial LiDAR scanner to make detailed topographic maps of portions of the fan and the catchment headwalls. These temporary scanners are mounted on tripods and use light to re-create 3D models of the ground surface. Much of the region has been imaged with LiDAR from aircraft, but ground-based LiDAR can allow the team to see smaller scale features. D. At each camp, the team would like to install a temporary broadband seismometer so we can monitor the seismic activity occurring in the Aklavik Range. This instrument is shaped like a small suitcase with a similar-sized solar panel and will only be on-site while in camp. Continuous Monitoring A. As the team examine the fans, the team propose to look for ~20–30 sites at the top of the fan, mid-fan, and at the downstream end of the fan to make detailed measurements. At these sites, the team would like to dig very shallow pits (<1 meter deep) to document the presence of ice in the ground and install temperature sensors, or probes, to record the soil conditions. The team would only install ~5–6 probes in select locations, and these probes would remain in the soil for the duration of the study. They are ~1–2 m long PVC pipes with data loggers and would be removed in the last field season. B. In the catchment headwall regions, the team would like to install thermocouples and temperature loggers that would be placed within holes drilled into the bedrock. Small (<2-inch diameter) holes, ~50-100 cm deep, will need to be drilled into the bedrock with a gasoline-powered drill to place these sensors deep enough to examine the annual temperature fluctuations within the headwall catchments. These sensors would remain in the catchment walls for the duration of the study and be removed when the team are finished with the project during the last field season. C. The team propose to install two weather stations, one in each of the Red and Black Mountain catchments. These weather stations are approximately 2 m tall and have small solar panels and batteries that are mounted on steel tripods. These stations can facilitate continuous daily weather data logging throughout the year. D. Finally, the team would like to install two stream gauges, one in each of the active channels in both the Red and Black Mountain fan systems. These stream gauges consist of small cameras mounted on steel-frame tripods that also have a battery and solar panel. They would be removed at the end of the study in the final field season. Sampling A. At the same ~20–30 monitoring sites where the team dig the soil pits(discussed above), the team would also collect small samples of soil for documenting the history of sediment accumulation and the movement of the sediment during (~1 L total/pit). B. In the bedrock catchment areas, the team propose to collect the cores that are drilled into the bedrock, along with ~10-20, 1–2 kg rock samples for geochemical analysis. These would be sampled throughout the catchment systems and would be collected with rock hammers. C. Along the fan surfaces and in the active channels themselves, the team propose to collect ~25 samples of woody or plant debris for radiocarbon dating. These will enable the team to precisely constrain the ages of ancient fan deposits. In addition, the team propose to collect a similar number of sediment samples to constrain the type of sediments that are being transported within the active channels. D. Finally, using a small raft or boat, the team propose to drill two sediment cores in the lakes in front of each the Black and Red Mountain fans. This will be done using a Livingston core in collaboration with Dr. Jen Galloway of the Geological Survey of Canada. The research team have already begun conversation with members of the Gwich’in Tribal Council, Ehdiitat Gwich’in Council, Gwich’in Renewable Resources Board, Gwich’in Land and Water Board, Aklavik Hunters and Trappers Committee, and Gwich’in Department of Cultural Heritage. The team are currently in the process of applying for special permission to work on Gwich’in Private Lands, and have begun conversations about hiring wildlife monitors during each of the field seasons. All of this is helped by prior experience working in this region, so the team are excited to expand the scope of the interactions with the local communities. To ensure consistent communication with NWT stakeholders, the team will plan to have annual meetings with these interested parties to update them on the research progress. In addition, the team plan to engage in the local community through a combination of public lectures and traditional knowledge collaborative projects. The team are currently in discussion with members of the Gwich’in Department of Cultural Heritage about how and when to organize these arrangements, so this is a work in progress. The team are also hoping to engage local community members in our research project as some of our monitoring equipment will require maintenance during the year. The fieldwork for this study will be conducted from July 15, 2023 to August 31, 2023.