POLARIS (seismology)

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POLARIS (Portable Observatories for Lithospheric Analysis and Research Investigating Seismicity) was an underground seismology project at SNOLAB, a deep underground science laboratory near Sudbury, Ontario, Canada. The system used several three-point broadband seismograph stations located above Creighton Mine and inside the mine, with two stations on the surface and others at depths of about 1 to 2 kilometers. The deep placement allowed very clear measurements of seismic waves.

POLARIS helped both academic research and monitoring efforts. Its data were used by the Canadian National Data Centre for earthquake and nuclear-explosion monitoring. The project gained particular note for capturing detailed signals from the magnitude-4.1 Sudbury-area earthquake on November 26, 2006, with the 2-kilometer-deep POLARIS station only about 300 meters above the earthquake’s focus.

SNOLAB, where POLARIS was deployed, is the world’s deepest underground cleanroom facility, located in the Creighton Mine within the Sudbury Basin. It sits about 2 kilometers underground, providing roughly 6,010 meters water equivalent of shielding from cosmic rays and extremely low background radiation, which is ideal for sensitive experiments.

In short, POLARIS was a deep-placing seismology setup designed to study earthquakes and seismicity in hard rock, using data from stations both above and inside a deep mine.