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Subbottom Seismic Profiling
Tim Patterson Nawaf Nasser SyQwest Stratabox Sub-bottom Profiler
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Subbottom Seismic Stratigraphy
1962 to present Holocene lake sediments Proto-Great Slave Lake
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Subbottom Seismic Stratigraphy
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Glew Coring ~1990 ~1962 Nawaf Nasser
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Glew Coring – Black Layer
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Glew Core – Sedimentology
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Thickness and Volume of Arsenic Contaminated Layer
X = 23.3 cm thick Drafted by: D. Monita Volume All Layers 206,000 m3
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Thickness and Volume of Contaminated Layer
Range As (ppm) Average As (ppm) Mean Thickness Volume (m^3) All Layers 0.233 Layer 1 264 0.0362 Layer 2 787 0.0188 Layer 3 1370 0.0195 Layer 4 482 0.0688 Layer 5 255 0.0897 Bins Range As (ppm) Volume (m^3) Bin 1 Bin 2 Bin 3 Total 205972 Land Area 884000
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Thickness and Volume of Arsenic Contaminated Layers
1 2 3 3.6 cm 1.9 cm 2.0 cm 33,000 m3 16,900 m3 17,200 m3 100 to 500 ppm 500 to 1000 ppm 1000 to 1500 ppm Volume All Layers 206,000 m3 4 5 6.9 cm 9.0 cm 60,800 m3 79,300 m3 X = 23.3 cm 500 to 1000 ppm 100 to 500 ppm
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Urban development has impacted water input and output from Frame Lake
Urban runoff influenced Inlet Urban development has impacted water input and output from Frame Lake Causeway ~1975 Trailer Park Seepage
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Recommendation 1 Up to 40 cm of allochtonous sediment
Urban runoff influenced Inlet Up to 40 cm of allochtonous sediment In lake deposited over relatively short time Dredge material to return lake to early 20th century water depth and substrate type. Causeway ~1975 Trailer Park Seepage
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Recommendation 2 Flow through lake too slow.
Urban runoff influenced Inlet Flow through lake too slow. Permits build-up of nutrients in water column. Increase flow rate at sluice gate outline by causeway. Causeway ~1975 Trailer Park Seepage
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Recommendation 3 Only true stream inlet in at SW corner of lake.
Urban runoff influenced Inlet Only true stream inlet in at SW corner of lake. Permits nutrient laden water from suburban/urban area to enter lake. Construct Storm Water Management (SWM) Pond on site. Causeway ~1975 Trailer Park Seepage
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