144. Coastal Survey Cap (1991)
This cap identified one of three monuments marking cross-shore survey transects established by the Geological Survey of Canada at the Canada-US border on the Yukon North Slope coast in 1991. In August 2015, it was recovered just as the monument was about to fall over the lip of the bluff, which over time had eroded back 33 metres. Indeed, the history of coastal monitoring at this site goes back to 1972, when Survey researchers documented 43 metres of shoreline retreat relative to an International Boundary Commission marker erected in 1912.
The Survey has installed monuments at shoreline monitoring sites in seven provinces and all three territories. By 2012, there were about 600 survey sites, of which 67 have records spanning more than 20 years. Almost half of these sites are located in the Arctic, an area that accounts for over half of Canada’s coast. Shore stability monitoring supports scientific understanding and advice on coastal management for infrastructure safety, cultural resource conservation, and habitat protection.
Survey techniques have evolved from rods and tape, optical theodolites, to the real-time GPS instruments used today. Ground surveys are enhanced and extended using soft photogrammetry with historical air photos, high-resolution satellite imagery, airborne scanning laser altimetry, and, just recently, drone imagery.
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