S-Wave Imaging of Glacial Overdeepened Alpine Valleys – Single-Component

Seismic characterization of the shape and the infill of overdeepened Alpine valleys have been conducted in the past with great success using P-waves. In advance of an ICDP drilling project the Leibniz Institute of Applied Geophysics evaluates the potential of S-wave imaging for this task at two test locations.

We achieved quite different results regarding the SH-wave seismic technique. In one test area we recorded very good results enabling us to differentiate facies inside the sediments from only several m below the surface up to the base of the basin at ∼200 m depth. Here, the very near surface information clearly supplements the information of the P-wave survey. Most of the information in SH-wave sections comes from relatively small offsets, enabling a way to efficient 3D sampling. However, other profiles in this location do not allow a sediment differentiation due to disturbing surface waves. In the other test area, reflected energy as deep as 600 m could be recovered, however we were not able up to now to focus it into interpretable sections.