A passive seismological experiment across the northern boundary
of the
Tornquist Fan was
carried out from December 1994 until April 1995 along a 100 km long profile
in Denmark and Sweden.
Observed PS converted seismic waves indicate an abrupt increase in Moho
depth
of 4–5 km within 5 km
horizontal distance at about 50 km to the northeast of the Øresund.
This is a much sharper jump than that
inferred from the wide-angle data of EUGENO-S line 1. Preliminary analysis
of
seismic shear wave
anisotropy indicates asthenospheric mantle flow parallel to the Sorgenfrei-Tornquist
Zone. These parallel
directions are already observed between the Elbe Line and the Sorgenfrei-Tornquist
Zone while further
south in central Europe the flow directions follow the trend of the Alpine
belt.