The basic principles of surface wave ambient noise seismology have been known for decades; a seismic signal is recorded by adjacent seismometers; the difference between the two recordings provides information about the intervening underlying rock.
Tomography. Sisprobe has developed techniques, workflows and codes to treat massive amounts of data recorded in month-long surveys by large surface arrays (100 to >2000 sensors). This produces high-resolution tomographic images of the subsurface.
Monitoring. By recording continuously for weeks or months, or by making regular measurements, changes in sub-surface structure are registered. This allows Sisprobe to monitor evolution of oil or gas reservoirs, or changes during excavation of structures in urban settings (e.g. metro tunnels)
The technique has been successfully applied for imaging the crust (Shapiro et al. 2005) and monitoring fault zones (Brenguier et al. 2019a).
It also allows imaging and monitoring the subsurface for industrial applications including oil & gas (Chmiel et al, 2019; Brenguier et al, 2019b) mine safety (Olivier et al. 2015) and mineral exploration (Dales et al, 2020)