1887

Abstract

Summary

We re-process high-resolution shallow seismic reflection data collected over glacial deposits in Heby, Southeastern Sweden, to accurately map the dipping bedrock topographies and enhance the quality of the seismic images of groundwater bearing structures. We apply Kirchhoff pre-stack depth migration (PSDM) on the pre-stack processed data and compare our results with post-stack time migrated (PSTM) depth converted results. The velocity models calculated from first arrivals of shot gathers are used as initial models for travel time tomography. The velocity model estimated from the first-arrival tomography is used as a starting point for the pre- and post-stack migration. We observe that PSDM improves the seismic image. Especially reflections from the water table and dipping structures became prominent and continuous, and the reflectors are located more accurately, when borehole information is considered. The seismic image shows a water table around 35m elevation. The uppermost, about 20m overburden represents clay and constitutes sub-horizontal reflectors. This layer is underlain by sand/gravel deposits overlying the undulated bedrock. Our work shows that PSDM can help to obtain reliable near-surface images, contributing to reliable and sustainable groundwater management.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201902479
2019-09-08
2020-04-08
Loading full text...

Full text loading...

References

  1. Bachrach, R. and Nur, A.
    [1998] High-resolution shallow-seismic experiments in sand, Part 1: Water table, fluid flow, and saturation. Geophysics63(4):1225–1233.
    [Google Scholar]
  2. Bradford, J. H.
    [2002a] Depth characterization of shallow aquifers with seismic reflection, Part I, The failure of NMO velocity analysis and quantitative error prediction. Geophysics, 67, 89–97.
    [Google Scholar]
  3. Bradford, J. H. and Sawyer, D. S.
    [2002] Depth characterization of shallow aquifers with seismic reflection - Part II: Pre-stack depth migration and field examples. Geophysics, 67, 98–109.
    [Google Scholar]
  4. Buker, F., Green, A., and Horstmeye, H.
    [1998] Shallow 3-D seismic reflection survey: Data acquisition and preliminary processing strategies. Geophysics, 63, 1434–1450.
    [Google Scholar]
  5. Juhlin, C., Palm, H., Müllern, C.-F. and Wâllberg, B.
    [2002] Imaging of groundwater resources in glacial deposits using high-resolution reflection seismics, Sweden. Journal of Applied Geophysics, 51, 107–120.
    [Google Scholar]
  6. Maries, G., Ahokangas, E., Mäkinen, J., Pasanen, A., Malehmir, A.
    [2016] Interlobate esker architecture and related hydrogeological features derived from a combination of high-resolution reflection seismics and refraction tomography, Virttaankangas, southwest Finland. Hydrogeology Journal25(829):845.
    [Google Scholar]
  7. Pugin, A., Pullan, S., Hunter, J. and Oldenborger, G.
    [2009] Hydrogeological prospecting using P-and S-wave landstreamer seismic reflection methods. Near Surface Geophysics, 7, 315–327.
    [Google Scholar]
  8. Tryggvason, A., Rögnvaldsson, S. and Flovenz, O.
    [2002] Three-dimensional imaging of the P- and S-wave velocity structure and earthquake locations beneath Southwest Iceland. Geophysical Journal International, 151, 848–866.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201902479
Loading
/content/papers/10.3997/2214-4609.201902479
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error