10.4122/1.1000000400
Günther, Thomas
Thomas
Günther
t.guenther@gga-hannover.de
Bentley, Laurence
Laurence
Bentley
lbentley@ucalgary.ca
Günther, Thomas
Thomas
Günther
t.guenther@gga-hannover.de
A new joint inversion algorithm applied to the interpretation of dc resistivity and refraction data
XVI International Conference on Computational Methods in Water Resources
2006
2006
A new joint inversion algorithm that can be applied to independent physical
parameters has been developed. The method allows the interchange of structural
information between otherwise independent inversions. It is based on the principles
of model-sided robust modeling and the structures in the opposing inversion model are
supported and not strictly enforced. The algorithm uses unstructured meshes that
allow the incorporation of topography and other information on the geometry of the
subsurface.
A synthetic study on a simple model structure is done using refraction tomography and
dc resistivity inversion. On one hand, an existing boundary in one parameter does not
enforce the same structure in the other. However, the inversion results are
significantly improved yielding a clearer separation of units by means of cluster
analysis.
The algorithm will be applied to the Pine Creek site in Calgary, Alberta, Canada. The
site is underlain by approximately 6 m of unsaturated gravel overlying a shaly,
weathered sandstone bedrock. Repeated profiles using electrical resistivity, seismic
refraction and ground penetrating radar surveys were conducted in support of a
groundwater study. The joint electrical resistivity-seismic refraction inversion will
be constrained using data from well logs and GPR reflection events. The joint
inversion reduces the ambiguity in the inversions and consequently improves the final
stratigraphic model. Improved stratigraphic models will result in an improved ability
to model groundwater flow and transport.