Title: Mercury contamination in permafrost in the Jean Marie River First Nation Lands (dehcho region)
Citation: Cardinal, G., Jean Marie River First Nation. (2016). Mercury contamination in permafrost in the Jean Marie River First Nation Lands (dehcho region). NWT Discovery Portal. https://nwtdiscoveryportal.enr.gov.nt.ca/geoportal/catalog/search/resource/details.page?uuid=%7BD9195BF4-4C7F-427D-A63E-E28A486C551E%7D
Study Site: Jean Marie River First Nation, Northwest Territories
Purpose: A first set of data evaluates the contribution of degrading permafrost to the mercury contamination of lakes and fish around Jean Marie River First Nation (JMRFN). Total mercury was analysed for 19 permafrost samples and can be compared to mercury contamination of fish and water of the same area (data collected by another project team and not included in these data sets). Other sets of data were developed to study the composition of permafrost and its content in ice, which gives information on the current conditions of permafrost and monitor its degradation. This allows to gain knowledge of the structure and current conditions of permafrost.
Abstract: Freeze-dried, homogenized permafrost samples (sediment and peat) were analyzed for total Hg on a Milestone® DMA-80 Direct Mercury Analyzer using methods described in EPA method 7473 (U.S.EPA, 2007). The calibration detection limit was 1 ng/g. Every 10 samples, duplicate samples were analyzed (% deviation: 3.7 and 13.6, n=2). A certified reference material (CRM; MESS-3 (0.091 ± 0.009 mg/kg Hg) was analyzed at the start and end of the run (mean recovery: 93.0 ± 0.06, n=3). Blanks were analyzed at the start, end, and every 10 samples (mean: 0.08 ± 0.03 ng, n=4). Permafrost samples were collected on the field with a portable GÖLZ Earth-drill system and brought to the lab for analysis. Sieve analysis of grain size were performed following a specifically modified American Standard and Testing Method protocol (ASTM D422-63, 2000). The volumetric ice content was calculated by immersing the frozen sample, bagged in vacuum-sealed polybags, in a recipient to measure its volume (Vtot). The sample was then thawed and put in the oven to dry. The remaining dry material was immersed again to determinate its volume (Vsed). A log for each permafrost borehole was created by assembling laboratory photos of the cores. Borehole logs include maximal depths, grain size ratio and volumetric ice content (see Appendix 3 for all borehole log descriptions and data). These logs were used as supporting data for mapping. All analyses were performed for 4 permafrost sites and samples were collected at various depth. The data is stored in GIS (shape-file) and excel format.
Supplemental Information Summary:
Research:
Further Info:
Status: Complete
Keywords:
peat properties,
effects of disturbance,
metals,
permafrost,
Geographical coordinates: North: 62, South: 61 East: -120 West: -122
Bounding Temporal Extent: Start Date: , End
Date:
