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Permafrost and the NWT
Steve Kokelj, NWT Geological Survey
Permafrost and the NWT Steve Kokelj, NWT Geological Survey - - PowerPoint PPT Presentation
Permafrost and the NWT Steve Kokelj, NWT Geological Survey - - PowerPoint PPT Presentation
Permafrost and the NWT Steve Kokelj, NWT Geological Survey Objectives Permafrost 101 Why should we care? Challenges and opportunities Permafrost and the NWT environment Permafrost NWT is a permafrost Territory Heginbottom, 1995
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Permafrost and the NWT environment Permafrost
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NWT is a permafrost Territory
Heginbottom, 1995
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400 200 300 100
Adapted from S Wolfe, NRCan
Permafrost thickness
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Active layer
Active layer Post-disturbance active layer Ice-rich permafrost Surface subsidence
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Ground temperatures in permafrost
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Relations between air and ground temperatures
- S. Smith, NRCan
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Inuvik Tuktoyaktuk
Ground temperatures across tree line Inuvik to Tuktoyaktuk Highway Corridor
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Ice-rich permafrost
Massive tabular ice Relict ice (40-90% ice by volume) Active layer Paleoactive layer
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S
- me landscapes contain large
volumes of ice
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Ice-wedge ice
Thermal- contraction crack
Photo from CR Burn French, 1996
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Polygonal terrain
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Climate warming and permafrost
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- Env. Climate Change Canada
Warming air temperatures
- ver the past 50 years
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Permafrost is warming
1970 2005
Mackay, 1974; GSC Burn and Kokelj, 2009; PPP
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Eastern Banks Island
1960s
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2005
Eastern Banks Island
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2016
Eastern Banks Island
Rudy et al., 2017 GRL
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Increasing late season precipitation and land sliding
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Increasing fall precipitation 20 landslides in fall 2009
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Fall 2017 100 landslides occur after heavy rains
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Reindeer Station landslides occur after heavy rains, September 2017
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Geohazard risk maps are increasingly important for safety of residents and for planning infrastructure
Rudy et al., NWT Geoscience Forum, 2017
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Landscape responses
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Increasing value of permafrost geotechnical, ground temperature and geohazard data
Available ground temperature monitoring data Potential ground temperature monitoring data
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Monitoring, analysis, informed decisions and adaptation
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Summary
- Permafrost is the geological manifestation of climate and provides
foundation for billions of dollars of northern infrastructure and ecosystems
- The state of permafrost is being altered by climate warming
- S
- me permafrost landscapes are inherently susceptible to change
- Consider uncertainty and anticipate encountering conditions without
precedent
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Summary
- Information on permafrost temperature and geotechnical properties is
critical for design and mitigation
- Assessing geohazards and risk related to permafrost thaw is critical for
public safety and for informed design
- Monitoring can inform mitigation and future design
- Managing this information is a foundational activity
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Summary
- Expect surprises, consequence of a poor knowledge base will be bigger
and more costly surprises
- Resilience – build in flexibility and develop multiple options to deal with
change and uncertainty
- There is no formal permafrost monitoring or data management systems,
- r teams in place to monitor, analyze and report
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Summary
Permafrost has emerged as the critical knowledge base to inform
climate change adaptation
Training and capacity is required – Invest in people Northern Challenges - S
- lutions with Northerners – Northern Capacity
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Current status?
Are we able to make informed decisions? Are we able to assess risk to infrastructure and human health? Are we able to provide an information base that supports planning, adaptation, innovation, development and a resilient Territory?
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Thank you
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Impacts to northern infrastructure
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2015
Fill Tongue Slumps Failure precursor
2016
Embankment Failure
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