Deltaic Lake Sediments as Recorders of Past Carbon Export from Arctic River Drainage Basins

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: climate change, permafrost degradation, sedimentology, sediment transport

Principal Investigator: Eglinton, Timothy I (2)
Licence Number: 14479
Organization: Woods Hole Oceanographic Institution
Licensed Year(s): 2011 2009 2007
Issued: Mar 09, 2009
Project Team: Dr. Liviu Giosan (Co-principal Investigator, Woods Hole Oceanographic Inst.), Dr. Valier Galy (Postdoctoral Investigator, Woods Hole Oceanographic Inst.), Mr. Daniel Montlucon (Research Associate, Woods Hole Oceanographic Inst.), Mr. David Griffith (Graduate Research Assistant, Woods Hole Oceanographic Inst.), Mr. James Saenz (Graduate Research Assistant, Woods Hole Oceanographic Inst.), Dr. Timothy Eglinton (Co-principal Investigator, Woods Hole Oceanographic Inst.), Dr. R. Max Holmes (Collaborator, Woods Hole Research Center)

Objective(s): The objectives of this research is to determine whether the researchers can reconstruct past changes in carbon export from the Mackenzie River from lake sediment records in the Delta. This will provide a context for assessing whether carbon discharge is changing in response to changing climate.

Project Description: This licence is being issued for the scientific research application no. 955.

The objective of this research is to collect sediment cores from the Mackenzie River Delta in order to study how the river has behaved in the past, and see if the researchers can detect recent changes due to thawing permafrost. More specifically, the goal is to determine whether the researchers can reconstruct past changes in carbon export from the Mackenzie River from lake sediment records in the Delta. This will provide a context for assessing whether carbon discharge is changing in response to changing climate.

Sampling is planned for late winter, when the lakes in the delta are still frozen. This makes sampling easier since the researchers can core through the ice and no floating platform is needed. It also enables access via ice roads/skiddoo or by helicopter for more remote lakes. Lake sediment cores of different lengths (between 0.5m and 5m) will be obtained using different methods. The researchers will use simple piston cores to collect short cores. The piston cores are a simple piece of 10cm diameter plastic tubing (typically < 2 m long) with a plunger in the middle that is pushed manually into the mud The vibracore is similar diameter but is made of aluminum and is longer (up to 5 m). Vibrations from a gas-driven portable motor are used to help the corer penetrate more deeply into the mud (see photo provided). After the cores are pulled out of the mud they are put in boxes and transported back to Inuvik by sled for further processing. In most cases, the cores will be shipped intact back to our laboratory in Woods Hole, Massachusetts, USA, but in some cases we will sample the cores and place the samples in glass jars or plastic bags prior to shipment.

The researchers will also use a ground penetrating radar (GPR) survey of each lake to find the deepest location in the lake (the best place to core). The radar survey is done by pulling the box behind a skidoo. Both corers and the GPR were used successfully during our prior fieldtrip to the Mackenzie Delta in April 2007. Each of these coring systems are quite portable and easy to transport by skidoo or helicopter.

The researchers welcome local involvement in this project, both in terms of participation in fieldwork and subsequent studies of the samples recovered. Please contact them if you are interested.

The fieldwork for this project will be conducted on numerous Mackenzie Delta Lakes near East, West and Peel Channels from March 22 to April 12, 2009. Exact locations can be obtained from the researcher.