1887

Abstract

Summary

In Norway, resistivity measurements have already been tested in marine environments in order to detect subsea fracture zones. However, most of these data have been processed without taking into account the special conditions the presence of seawater creates. More recent studies worldwide have also applied ERT in marine conditions, but under more favorable conditions nevertheless since they dealt with brackish water of considerably higher resistivity than pure seawater. This study summarizes our efforts to establish basic rules when considering whether or not pure sea water ERT can satisfactorily detect weak zones inside resistive bedrock, a problem engineers in Norway usually come up against in tunnel construction sites. The scope for this study is related to the construction of a sub-sea tunnels and the potential application of ERT to detect fractured zones as part of the geotechnical study. Our results indicate that ERT surveys for fracture zone detection in Norwegian marine environments can be promising under certain conditions but at the same time ambiguous since they suffer from reduced resolution and major artificial effects. Based on the modeling results, we were able to improve interpretations of ERT measurements made across the straits at Kvitsøy and plan further investigations in southern Norway.

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/content/papers/10.3997/2214-4609.20142126
2014-09-08
2020-08-06
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References

  1. Dahlin, T., Loke, M.H., Siikanen, J. and Höök, M.
    [2014] Underwater ERT Survey for Site Investigation of a New Line for the Stockholm Metro. 31st Nordic Geological Winter Meeting, Lund, Sweden, January 8–10 2014. Abstract in conference proceedings.
    [Google Scholar]
  2. Dalsegg, E.
    [2012] Geofysiske målinger på Kvitsøy, Kvitsøy kommune, Rogaland. NGU Report 2012.033, 1–17.
    [Google Scholar]
  3. Dalsegg, E. and Elvebakk, H.
    [2012] Geofysiske målinger i forbindelse med undersjøisk tunnel til Bjarkøy, Troms. NGU Rapport 2012.027, 1–41.
    [Google Scholar]
  4. Elvebakk, H. and Saintot, A.
    [2011] Geofysisk logging av borehull på Alstein, Randaberg kommune, Rogaland. NGU Report 2011.032, 1–43.
    [Google Scholar]
  5. Ganerod, G.V., Rønning, J.S., Dalsegg, E., Elvebakk, H., Holmøy, K., Nilsen, B. and Braathen, A.
    [2006] Comparison of geophysical methods for sub-surface mapping of faults and fracture zones in a section of the Viggja road tunnel, Norway. Bull. Eng. Geol. Env, 65, 231–243. ISSN: 1435–9529 (Paper) 1435–9537 (Online).
    [Google Scholar]
  6. Kim, J.H.
    [2012] DC 2DPro v. 0.99. User’s Guide.
    [Google Scholar]
  7. Lile, O.B., Backe, K.R., Elvebakk, H. and Buan, J.E.
    [1994] Resistivity measurements on the sea-bottom to map fracture zones in the bedrock underneath sediments. Geophysical Prospecting, 42(7), 813–824.
    [Google Scholar]
  8. Loke, M.H.
    [2002] RES2DMOD ver 3.01 Geoelectrical Imaging 2D & 3D. Instruction manual.
    [Google Scholar]
  9. [2010] RES2DINV ver. 3.59. Geoelectrical Imaging 2D & 3D. Instruction manual.
    [Google Scholar]
  10. Reiser, F., Dalsegg, E., Dahlin, T., Ganerød, G. and Ronning, J.S.
    [2009] Resistivity Modelling of Fracture Zones and Horizontal Layers in Bedrock. NGU Report 2009.070, 1–120.
    [Google Scholar]
  11. Ronning, J.S., Dalsegg, E., Elvebakk, H., Ganerød, G.V. and Heincke, B.H.
    [2009] Characterization of fracture zones in bedrock using 2D resistivity. Proceedings from 5th Seminar on Strait Crossings, Trondheim, June 21–24 2009, 439–444 (SINTEF/NTNU).
    [Google Scholar]
  12. Rucker, D.F. and Nooman, G.E.
    [2013] Using marine resistivity to map geotechnical properties: a case study in support of dredging the Panama Canal. Near Surface Geophysics, 11(6), 625–637. doi:10.3997/1873‑0604.2012017.
    https://doi.org/10.3997/1873-0604.2012017 [Google Scholar]
  13. Satriani, A., Loperte, A. and Proto, M.
    [2011] Electrical Resistivity Tomography for coastal salt water intrusion characterization along the Ionian coast of Basilicata Region (Southern Italy). Fifteenth International Water Technology Conference, IWTC-15 2011, Alexandria, Egypt.
    [Google Scholar]
  14. Tassis, G., Tsourlos, P., Rønning, J.S. and Dahlin, T.
    [2014] Detection and characterization of fracture zones in bedrock in a marine environment - possibilities and limitations. NGU Report 2013.17, 1–72.
    [Google Scholar]
  15. Tsourlos, P.I., TsokasG.N. and Albanakis, K.
    [2001] Geoelectrical surveys in marine environments. Geowaters Project Report, 2001.
    [Google Scholar]
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