Evolving Inversion Methods in Geophysics with Cloud Computing - A Case Study of an eScience Collaboration

Magnetotellurics is a geophysics technique for characterisation of geothermal reservoirs, mineral exploration, and other geoscience endeavours that need to sound deeply into the earth -- many kilometres or tens of kilometres. Central to its data processing is an inversion problem which currently takes several weeks on a desktop machine. In our new eScience lab, enabled by cloud computing, we parallelised an existing FORTAN program and embedded the parallel version in a cloud-based web application to improve its usability. A factor-of-five speedup has taken the time for some inversions from weeks down to days and is in use in a pre-fracturing and post-fracturing study of a new geothermal site in South Australia, an area with a high occurrence of hot dry rocks. We report on our experience with Amazon Web Services cloud services and our migration to Microsoft Azure, the collaboration between computer scientists and geophysicists, and the foundation it has laid for future work exploiting cloud data-parallel programming models.