TUNB Velo 2.0: Large-scale velocity modelling of the North German Basin – Results from Lower Saxony

During the TUNB Velo 2.0 project, the Geological Surveys of the North German Federal States and the Federal Institute for Geosciences and Natural Resources (BGR) developed a seismic velocity model of the North German Basin. It is based on the TUNB structural model from the previous TUNB project, which covers 13 stratigraphic units from Zechstein to Tertiary, numerous salt structures and faults.

For Lower Saxony, the modelling was done in Aspen SKUA®. A volume model was derived from the structural model and parameterized with seismic velocities. The regional velocity approach is based on Jaritz et al. (1991), where the interval velocities of the stratigraphic units can be derived from their theoretical surface velocities and gradients (V0-K method).

The resulting regional velocity model of the TUNB Velo 2.0 project covers almost all of Lower Saxony, with the exception of the southernmost areas where the availability of seismic data is limited. At the LBEG, 75% of the 3D and 83% of the 2D seismic data is available only in time domain. With the velocity model now available, time domain seismic data can be converted to depth domain for its use in structural modelling. In the talk, we will present modelling results, show uncertainty considerations and the usage of this regional velocity model to convert seismic data.

References:

Jaritz W., Best G., Hildebrand G., Jürgens U. (1991) Regionale Analyse der seismischen Geschwindigkeiten in Nordwestdeutschland. Geol Jahrb 45:23–57