Open image in new windowCombining Terrestrial and Waterborne Geophysical Surveys to Investigate the Internal Composition and Structure of a Very Slow-Moving Landslide Near Ashcroft, British Columbia, Canada

  • David HuntleyEmail author
  • Peter Bobrowsky
  • Melvyn Best
Conference paper


A vital section of Canada’s national railway transportation corridor traverses a 7 km-long section of unstable terrain in the Thompson River valley, British Columbia. Landslides in this region have adversely impacted vital national railway infrastructure and operations, the environment, cultural heritage features, communities, public safety and economy since the late 19th Century. To help manage the potential risks associated with railway operations across this active slide zone, field investigations and monitoring of a very slow-moving Ripley Landslide are being undertaken by a consortium of research partners from government, academia and industry. Knowledge of the internal composition and structure of the landslide as interpreted through surficial geology mapping and geophysical surveys provide contextual baseline data for interpreting monitoring results; in addition to understanding mass-wasting processes in the Thompson River transportation corridor. Bathymetry, electrical resistivity tomography, frequency-domain electromagnetic terrain conductivity, ground penetrating radar, seismic refraction, multi-spectral surface wave analyses, and borehole logging of natural gamma, conductivity and magnetic susceptibility all suggest a moderately high relief bedrock sub-surface overlain by a >20 m thick package of clay, silt, till diamicton, gravel containing groundwater. Planar physical sub-surface features revealed in geophysical profiles and logs include tabular bedding and terrain unit contacts. Field observations and geophysical profiles also show curvilinear-rectilinear features interpreted as sub-horizontal translational failure planes in clay-rich beds beneath the rail ballast and lock-block retaining wall at depths between 5 and 15 m below the surface of the main landslide body. The landslide toe extends under the Thompson River where clay-rich sediments are confined to a >20 m deep bedrock basin. The upper clay beds are armoured from erosion by a lag deposit of modern fluvial boulders except along the west river bank where a deep trough has been carved by strong currents. High waterborne conductivity levels indicate discharge of groundwater through the boulder lag. Fluvial incision of the submerged toe slope at the south end of the landslide is observed <50 m west of where critical railway infrastructure is at risk. Integrating data from surficial geology mapping and an array of geophysical techniques provided significantly more information than any one method on its own.


Railway infrastructure Landslide Surficial geology mapping Geophysical surveys Electrical resistivity tomography Fixed frequency electromagnetic terrain conductivity Ground penetrating radar Seismic refraction Multi-spectral surface wave analysis Borehole conductivity Natural gamma Magnetic susceptibility 



We wish to thank Neil Parry, Megan Caston, Cassandra Budd and Gordon Brasnett (Tetra Tech EBA Inc., Edmonton, Alberta) for their geophysical services in 2013–2014; Paul Bauman, Landon Woods and Kimberly Hume (Advisian, Worley Parsons Group, Calgary, Alberta) in 2014–2015; and Cliff Candy, Caitlin Gugins and Heather Ainsworth (Frontier Geosciences Inc., North Vancouver, British Columbia) in 2015. Over the years, the project has benefited from management by Carmel Lowe, Adrienne Jones, Philip Hill (GSC Sidney, British Columbia), Andrée Blais-Stevens (GSC Ottawa); and Sharon Philpott and Merrina Zhang (Transport Canada, Ottawa, Ontario). Coordination of the Railway Ground Hazard Research Program was managed by Cindy Hick (HPB Association Management, Ottawa, Ontario). The following colleagues contributed on site and in the office, and ensured researchers operated in safety: Wendy Sladen and Baolin Wang (GSC Ottawa, Ontario), Lionel Jackson (GSC Vancouver, British Columbia), Erin Dlabola (GSC Sidney), Laura Weise (GSC International Intern, University of Potsdam, Germany) and Karolin Döringer (GSC International Intern, University of Vienna, Austria); Zhang Qing, Zhang Xiaofei and Lv Zhonghu (Centre for Hydrogeology and Environmental Geology, China Geological Survey, Baoding, China); Hengxing Lan (Chinese Academy of Sciences, Beijing, China); Michael Hendry, Derek Martin, Renato Macciotta, Matthew Schafer, Gael Le Meil, Jeffrey Journault and Kristen Tappenden (University of Alberta, Civil and Environmental Engineering, Edmonton, Alberta); Chris Bunce, Gary Maximiuk, Roy Olsen and Matt Rhoades (Canadian Pacific Railway); Tom Edwards, Jennifer Kutchner and Mark McKay (Canadian National Railway); and Ian Chadwick (ERD Consulting Ltd., Kamloops, British Columbia).


  1. Best M, Bobrowsky P, Douma M, Carlotto V, Pari W (2009) Geophysical surveys at Macchu Picchu, Peru: results for Landslide Hazards Investigations. In K. Sassa, P. Canuti (eds), Landslides—disaster risk reduction, pp 265–273, Springer, BerlinGoogle Scholar
  2. Bichler A, Bobrowsky P, Best M, Douma M, Hunter J, Calvert T, Burns R (2004) Three-dimensional mapping of a landslide using a multi-geophysical approach: the Quesnel Forks landslide. Landslides 1(1):29–40. doi: 10.1007/s10346-003-0008-7 (Contribution #2005492)
  3. Bishop N, Evans S, Petley D, Unger A (2008) The geotechnics of glaciolacustrine sediments and associated landslides near Ashcroft (British Columbia) and the Grand Coulee Dam (Washington). In: Proceedings of the 4th Canadian conference on Geohazards: from causes to management, 594 pGoogle Scholar
  4. Bobrowsky PT, Sladen W, Huntley D, Zhang Q, Bunce C, Edwards T, Hendry M, Martin D, Choi E (2014) Multi-parameter monitoring of a slow moving landslide: ripley slide, British Columbia, Canada. In: Lollino G, Giordan D, Battista Crosta G, Corominas J, Azzam R, Wasowski J, Sciarra N (eds) Engineering geology for society and territory—Volume 2 landslide processes, pp 155–159. IAEG (International Association of Engineering Geology and the Environment) Congress, Turin, Italy, 15–19 Sept 2014, Springer, Berlin (Contribution #20140007)Google Scholar
  5. Bunce C, Chadwick I (2012) GPS monitoring of a landslide for railways. In: Eberhardt et al. (ed), Landslides and engineered slopes: protecting society through improved understanding, pp 1373–1379Google Scholar
  6. Clague J, Evans S (2003) Geologic framework for large historic landslides in Thompson River valley, British Columbia. Environ Eng Geosci IX:201–212Google Scholar
  7. Eshraghian A, Martin D, Cruden D (2007) Complex earth slides in the Thompson River Valley, Ashcroft, British Columbia. Environ Eng Geosci XIII:161–181Google Scholar
  8. Eshraghian A, Martin D, Morgenstern N (2008) Movement triggers and mechanisms of two earth slides in the Thompson River Valley, British Columbia, Canada. Can Geotech J 45:1189–1209CrossRefGoogle Scholar
  9. Fulton RJ (1969) Glacial lake history, southern Interior Plateau, British Columbia. Geol Surv Can Pap 69–37, 14 pGoogle Scholar
  10. Hendry M, Macciotta R, Martin D (2015) Effect of Thompson River elevation on velocity and instability of Ripley Slide. Can Geotech J 52(3):257–267CrossRefGoogle Scholar
  11. Huntley D, Bobrowsky P (2014) Surficial geology and monitoring of the Ripley Slide, near Ashcroft, British Columbia, Canada. Geol Surv Can, Open File 7531, 21 pGoogle Scholar
  12. Huntley D, Bobrowsky P, Qing Z, Sladen W, Bunce C, Edwards T, Hendry M, Martin D, Choi E (2014) Fiber optic strain monitoring and evaluation of a slow-moving landslide near Ashcroft, British Columbia, Canada. In: Sassa K, Canuti P, Yin Y (eds) Landslide science for a safer geoenvironment, vol 1, p 415–422. Springer, Berlin. 3rd World Landslide Forum (ICL-IPL), Beijing, China 2–6 June 2014 (Contribution #20150019)Google Scholar
  13. Huntley D, Bobrowsky P, Parry N, Bauman P, Candy C, Best MT (2016a) Ripley landslide: the geophysical structure of a slow-moving landslide near Ashcroft, British Columbia, Canada. Geol Surv Can, Open File 8062, 59 pagesGoogle Scholar
  14. Huntley D, Bobrowsky P, Zhang Q, Zhang X, Lv Z, Hendry M, Macciotta R, Schafer M, Le Meil G, Journault J, Tappenden K (2016b) Application of optical fibre sensing real-time monitoring technology at the ripley landslide, near Ashcroft, British Columbia, Canada. In: Proceedings volume, Canadian Geotechnical Society, Geo Vancouver 2016 annual meeting, 13 pGoogle Scholar
  15. Huntley D, Bobrowsky P, Charbonneau F, Journault J, Hendry M (2017) Innovative landslide change detection monitoring: application of space-borne InSAR techniques in the Thompson River valley, British Columbia, Canada. In: Landslide research and risk reduction for advancing culture and living with natural hazards, 4th World Landslide Forum (ICL-IPL), Ljubljana, Slovenia 29 May–2 June 2017, vol 3, 13 pGoogle Scholar
  16. Johnsen T, Brennand T (2004) Late-glacial lakes in the Thompson Basin, British Columbia: paleogeography and evolution. Can J Earth Sci 41:1367–1383CrossRefGoogle Scholar
  17. Journault J, Macciotta R, Hendry M, Charbonneau F, Bobrowsky P, Huntley D, Bunce C, Edwards T (2016) Identification and quantification of concentrated movement zones within the Thompson River valley using satellite-borne InSAR. Proceedings volume, Canadian Geotechnical society, GeoVancouver2016 annual meeting, 13 pagesGoogle Scholar
  18. Lundström K, Jha VK, Rawat GS (2009) Mapping of quick clay formations using geotechnical and geophysical methods. Landslides 9(1):1–16CrossRefGoogle Scholar
  19. Macciotta R, Hendry M, Martin D, Elwood D, Lan H, Huntley D, Bobrowsky P, Sladen W Bunce C, Choi E, Edwards T (2014) Monitoring of the ripley slide in the Thompson River Valley, B.C. In: Proceedings of Geohazards 6 symposium, Kingston, Ontario, CanadaGoogle Scholar
  20. Merritt AJ, Chambers JE, Murphy W, Wilkinson PB, West IJ, Gunn DA, Meldrum PI, Kirkham M, Dixon M (2014) 3D ground model development for an active landslide in the Lias mudrocks using geophysical, remote sensing and geotechnical methods. Landslides 11(1):537–550CrossRefGoogle Scholar
  21. Monger J (1985) Structural evolution of the southwestern intermontane belt, Ashcroft and Hope map areas, British Columbia. Curr Res, Part A, Geol Surv Can, paper 85-1A, pp 349–358Google Scholar
  22. Monger J, McMillan W (1984) Bedrock geology of Ashcroft (92I) map area. Geol Surv Can, open file 980, scale 1:250,000 Google Scholar
  23. Mortimer N (1987) The Nicola Group: Late Triassic and early Jurassic subduction-related volcanism in British Columbia. Can J Earth Sci 24:2521–2536CrossRefGoogle Scholar
  24. Porter M, Savigny K, Keegan T, Bunce C, MacKay C (2002) Controls on stability of the Thompson River landslides. In: Proceedings of the 55th Canadian geotechnical conference: ground and water—theory to practice, Canadian Geotechnical Society, pp 1393–1400Google Scholar
  25. Ryder J (1976) Surficial geology, ashcroft, British Columbia. Geol Sur Can, A-Series Map 1405A, scale 1:126,720Google Scholar
  26. Ryder J, Fulton R, Clague J (1991) The Cordilleran Ice Sheet and the glacial geomorphology of southern and central British Columbia. Géog Phys Quatern 45:365–377Google Scholar
  27. Schafer M, Macciotta R, Hendry M, Martin D, Bunce C, Edwards T (2015) Instrumenting and monitoring a slow moving landslide. GeoQuebec 2015 paper, 7 pGoogle Scholar
  28. Tribe S (2005) Eocene paleo-physiography and drainage directions, southern Interior Plateau, British Columbia. Can J Earth Sci 42:215–230CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  1. 1.Geological Survey of CanadaVancouverCanada
  2. 2.Geological Survey of CanadaSidneyCanada
  3. 3.BEMEX Consulting InternationalVictoriaCanada

Personalised recommendations