Diego Domenzain – Thesis Defense

Where: BGYM 219
When: Wednesday, December 4th
Time: 2:00 pm
Directions: Map

Joint Inversion of GPR and ER data:

Imaging the subsurface can shed knowledge on important processes needed in modern day Human’s life such as ground-water exploration, water resource monitoring, contaminant and hazard mitigation, geothermal energy exploration and carbon-dioxide storage. As computing power expands, it is becoming ever more feasible to increase the physical complexity of Earth’s exploration methods, and hence enhance our understanding of the subsurface.

We use non-invasive geophysical active source methods that rely on electromagnetic fields to probe the depths of the Earth. In particular, we use full-waveform ground penetrating radar (GPR) and electrical resistivity (ER). We combine both types of data and let the different physical sensitivities of both methods cooperate in order to account for non-uniqueness of the subsurface image.

The demanding computing requirements of full-waveform GPR entail an unfeasible amount of memory for existing ER inversion methods. We develop a 2.5D ER adjoint method inversion that is capable of recovering accurate subsurface conductivity from field data and relaxes the amount of required memory. We test our method on field data from an alluvial aquifer site and find agreeable results with existing measurements in the literature. Having feasible computational methods for both GPR and ER inversions is an important step for using our joint inversion algorithms on field data.