Upstream migration of knickpoints: Geotechnical considerations

Dominique Turmel, Jacques Locat, Gary Parker

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Multiple knickpoints have been observed in recent years on the lakefloor of Wabush Lake, Labrador, Canada. Two or more sequential high-resolution geophysical surveys have revealed that these knickpoints tend to migrate updip, i.e. upstream relative to the turbidity currents that overflow them. In order to understand the different processes accountable for the migration of these knickpoints, laboratory studies have been performed to reproduce the sedimentological setting and hydrodynamics of Wabush Lake. Knickpoints are topographic depressions, characterized by a steep slope and a flatter profile downslope and upslope. In the present case they are initiated by morphodynamic interaction between an erodible bed and an overriding turbidity current. A set of 22 experiments have been performed in a facility able to run continuous turbidity currents. Knickpoints created in laboratory are up to 1 cm deep and migrate upstream at variable speed. Experimentation results show that migration of the knickpoints is controlled by two factors: erosion by the turbidity current and a landsliding process in the knickpoint head scarp. Knickpoint migration has also been observed when no turbidity current was present. These results show that this phenomenon is governed by not only hydraulics, as previously described in the literature, but must also be studied from a geotechnical point of view.

Original languageEnglish (US)
Title of host publicationSubmarine Mass Movements and Their Consequences - 5th International Symposium
PublisherKluwer Academic Publishers
Pages123-132
Number of pages10
ISBN (Print)9789400721616
DOIs
StatePublished - 2012
Event5th International Symposium on Submarine Mass Movements and Their Consequences - Kyoto, Japan
Duration: Oct 24 2011Oct 26 2011

Publication series

NameSubmarine Mass Movements and Their Consequences - 5th International Symposium

Other

Other5th International Symposium on Submarine Mass Movements and Their Consequences
CountryJapan
CityKyoto
Period10/24/1110/26/11

Keywords

  • Knickpoints
  • Landslides
  • Physical modeling
  • Turbidity currents

ASJC Scopus subject areas

  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Upstream migration of knickpoints: Geotechnical considerations'. Together they form a unique fingerprint.

  • Cite this

    Turmel, D., Locat, J., & Parker, G. (2012). Upstream migration of knickpoints: Geotechnical considerations. In Submarine Mass Movements and Their Consequences - 5th International Symposium (pp. 123-132). (Submarine Mass Movements and Their Consequences - 5th International Symposium). Kluwer Academic Publishers. https://doi.org/10.1007/978-94-007-2162-3_11