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Identifying landslide preconditions in Swedish quick clays—insights from integration of surface geophysical, core sample- and downhole property measurements

Salas-Romero, Silvia; Malehmir, Alireza; Snowball, Ian LU ; Lougheed, Bryan C. LU and Hellqvist, Magnus (2016) In Landslides 13(5). p.905-923
Abstract

Quick-clay landslides are a serious geohazard in Canada, Norway and Sweden. Identification and mapping of quick clays are essential endeavours because the damage caused by an individual landslide can be large and costly, with potentially fatal consequences. We collected geophysical borehole and soil core data from an area prone to quick-clay landslides in southwestern Sweden. Methodologies included in situ and laboratory measurements, providing information about natural gamma radiation, sonic velocities, electrical conductivity, pH, physical grain size, elemental and mineral composition, magnetic properties, cation exchange capacity and fossil content. A stratigraphic thickness of almost 60 m enables us to study quick clays and their... (More)

Quick-clay landslides are a serious geohazard in Canada, Norway and Sweden. Identification and mapping of quick clays are essential endeavours because the damage caused by an individual landslide can be large and costly, with potentially fatal consequences. We collected geophysical borehole and soil core data from an area prone to quick-clay landslides in southwestern Sweden. Methodologies included in situ and laboratory measurements, providing information about natural gamma radiation, sonic velocities, electrical conductivity, pH, physical grain size, elemental and mineral composition, magnetic properties, cation exchange capacity and fossil content. A stratigraphic thickness of almost 60 m enables us to study quick clays and their host environment in Sweden at unusually high resolution. Results identify the origin and location of reflections in nearby seismic lines and assign physico-chemical properties to the geological units present in the area. We show that coarse-grained layers are sandwiched between marine clays (some of which are quick clays). These layers function as a conduit for relatively fresh water that infiltrates the marine clays and chemically destabilizes them by leaching out their salts. The salinity distribution in the boreholes indicate that the groundwater movement is downwards, through the coarse-grained layer and towards the Göta river. The presence of these materials is important for the development of quick clays, although not a prerequisite. With the help of surface geophysical methods, the location of the coarse-grained layers can be known faster and more economically, which could be relevant for studying the potential for quick-clay landslide occurrence over large areas.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Correlation, Downhole geophysics, Landslide, Physico-chemical properties, Quick clay, Southwestern Sweden
in
Landslides
volume
13
issue
5
pages
19 pages
publisher
Springer
external identifiers
  • scopus:84944613791
  • wos:000385174600005
ISSN
1612-510X
DOI
10.1007/s10346-015-0633-y
language
English
LU publication?
yes
id
75dc3395-162e-461c-9ee8-e816ec42eec1
date added to LUP
2016-10-17 08:24:49
date last changed
2017-01-01 08:36:57
@article{75dc3395-162e-461c-9ee8-e816ec42eec1,
  abstract     = {<p>Quick-clay landslides are a serious geohazard in Canada, Norway and Sweden. Identification and mapping of quick clays are essential endeavours because the damage caused by an individual landslide can be large and costly, with potentially fatal consequences. We collected geophysical borehole and soil core data from an area prone to quick-clay landslides in southwestern Sweden. Methodologies included in situ and laboratory measurements, providing information about natural gamma radiation, sonic velocities, electrical conductivity, pH, physical grain size, elemental and mineral composition, magnetic properties, cation exchange capacity and fossil content. A stratigraphic thickness of almost 60 m enables us to study quick clays and their host environment in Sweden at unusually high resolution. Results identify the origin and location of reflections in nearby seismic lines and assign physico-chemical properties to the geological units present in the area. We show that coarse-grained layers are sandwiched between marine clays (some of which are quick clays). These layers function as a conduit for relatively fresh water that infiltrates the marine clays and chemically destabilizes them by leaching out their salts. The salinity distribution in the boreholes indicate that the groundwater movement is downwards, through the coarse-grained layer and towards the Göta river. The presence of these materials is important for the development of quick clays, although not a prerequisite. With the help of surface geophysical methods, the location of the coarse-grained layers can be known faster and more economically, which could be relevant for studying the potential for quick-clay landslide occurrence over large areas.</p>},
  author       = {Salas-Romero, Silvia and Malehmir, Alireza and Snowball, Ian and Lougheed, Bryan C. and Hellqvist, Magnus},
  issn         = {1612-510X},
  keyword      = {Correlation,Downhole geophysics,Landslide,Physico-chemical properties,Quick clay,Southwestern Sweden},
  language     = {eng},
  month        = {10},
  number       = {5},
  pages        = {905--923},
  publisher    = {Springer},
  series       = {Landslides},
  title        = {Identifying landslide preconditions in Swedish quick clays—insights from integration of surface geophysical, core sample- and downhole property measurements},
  url          = {http://dx.doi.org/10.1007/s10346-015-0633-y},
  volume       = {13},
  year         = {2016},
}