Craig W. Christensen

    Craig W. Christensen

    MSc student, Department of Geoscience, University of Calgary (Supervisor: Masaki Hayashi)

    Thesis Topic: Hydrogeophysical Survey of Groundwater Flow Pathways in an Alpine Headwater Basin


    Alpine regions of the Canadian Rocky Mountains are important sources of freshwater for the semiarid Canadian Prairies. Yet, only recently have studies demonstrated that groundwater plays an important role in storage and subsequent release of snowmelt and rain. With limited case studies available in this region, there is a limited understanding of which storage and flow processes are ubiquitous and which ones are novel and localized. To help develop a broader understanding of alpine hydrogeology in the Rocky Mountains, I am studying a new, first-order watershed in the Front Ranges. This complex site, near The Fortress in the Kananaskis Valley, is unique in having multiple geomorphological units and hydrologic features in close proximity, including large talus cones, an alpine meadow, concentric moraine ridges, a tarn lake with no surface outlet, and multiple groundwater springs. That complexity allows me to characterize the response of a variety of hydrogeological units in the same study.  

    Given the challenging ground conditions and difficult access of alpine basins, drilling wells and taking direct samples of subsurface hydrology is exceedingly difficult. Instead, I employ three geophysical methods: electrical resistivity tomography, seismic refraction tomography, and ground-penetrating radar. Combining these data sets, I can establish the geometry of different hydrogeological units and delineate saturated and unsaturated zones. Finally, by further integrating ground truth and hydrologic data, we develop a preliminary model of groundwater flow routing, whose main features are: separate shallow and deep flow systems in the talus, a subsurface reservoir under the meadow, and the presence of buried channels that feed the outlet spring. These insights will help subsequent modelers to assess the impact of climate change on water resources at a larger scale.

    Publications


    Peer-Reviewed Journal Articles

    • Lysdahl, A., Ahrens, S., Bazin, S., Christensen, C., & Günther, T. 2016. Comparison of 2D and 3D inversion for ERT engineering site investigations - A case study from Oslo Harbor. Near Surface Geophysics. [In Review]
    • Christensen, C., Pfaffhuber, A., Anschütz, H., Smaavik, T. 2015. Combining airborne electromagnetic and geotechnical data for automated depth to bedrock tracking. Journal of Applied Geophysics, 119, pp. 178 -191. doi: 10.1016/j.jappgeo.2015.05.008

    Conference Proceedings

    • Christensen, C.*, Pfaffhuber, A., Anschütz, H., & Smaavik, T. “Combining airborne electromagnetics with geotechnical data for automated depth to bedrock tracking” in Geoconvention 2015: New Horizons, Calgary, Canada, May 4-8, 2015
    • Christensen, C., Anschütz, H., & Pfaffhuber, A. “Automated Airborne EM and borehole data integration for depth to bedrock extraction” in ASEG-PESA 24th International Geophysical Conference and Exhibition - Geophysics and Geology Together for Discovery, Perth, Australia, February 15, 2015. doi:10.1071/ASEG2015ab256
    • Bazin, S., Pfaffhuber, A., Anschütz, H., Grøneng, G., & Christensen, C. “Tunnel pre-investigation: towards a resistivity to rock-quality transform” in Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics, Athens, Greece, September 8, 2014. doi:10.3997/2214-4609.20141960.
    • Anschütz, H., Christensen, C., & Pfaffhuber, A. “Quantitative Depth to Bedrock Extraction from AEM data” in Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics, Athens, Greece, September 8, 2014. doi: 10.3997/2214-4609.20141994
    • Pfaffhuber, A., Anschütz, H., Herman, S., Smaavik, T., Kåsin, K., Auken, E., Pedersen, J., Schamper, C., Sagbakken, A., Bjørvik, F., Effersø, F., & Christensen, C. “Airborne Electromagnetic Measurements for the new E16 Kløfta - Kongsvinger. A new and efficient method for mapping depth to bedrock and quick clay” in Fjellsprengningsteknikk/Bergmekanikk/Geoteknikk 2013, Oslo, Norway, November 22, 2013

    Awards and Scholarships


    Academic Awards

    • National Science and Engineering Research Council Canadian Graduate Scholarship (2015)
    • Canadian Society of Exploration Geophysicists Foundation Scholarship (2016)

    Conference Awards

    • Best of Denver 2016 : Selected as one of the top 4 of +200 papers at SAGEEP 2016, and invited to present at the European Association of Geoscientists and Engineers’ Near Surface Geoscience Division meeting in Barcelona in September 2015
    • Best Student Oral Presentation – Honourable Mention: Selected as one among the best oral presenters at Geoconvetion 2016 out of +300 presentations

    Other Information