Remote-sensing technique hastens subsurface surveys

Drilling into subsurface environments is time-consuming and destructive so geologists are increasingly turning to seismic imaging, which uses sonic sources at different locations to send acoustic waves deep underground and measuring the time it takes for the waves to return to receivers on the surface. The travel time of the waves depends on properties of materials they pass through, and this method is adept at identifying unique subsurface features such as pockets of water.

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Conventional seismic imaging is, however, still too slow to detect real-time geologic events.

“For a conventional seismic experiment, you need many different angular views to accurately estimate the properties of each substructure, which demands many hours to deploy and excite seismic sources over hundreds of different locations,” KAUST geophysicist Gerard Schuster said in a statement.

Schuster has been working on a solution to this issue by focusing on how the cyclical patterns of acoustic waves begin to lag or lead each other after passing through an underground material. According to KAUST, these phase differences can be inverted by seismic interferometry to provide high-resolution structural information while requiring far fewer audio sources.