Induced seismicity in Basel
The largest event prompted concern from local residents. The six borehole seismometers installed near the Basel injection well to monitor the natural background seismicity and the geothermal stimulation recorded more than 13,500 potential events connected with the geothermal project, from which 3,124 were of sufficient quality to permit [hypocenter] determinations in the period 2–12 December 2006, which spanned the main stimulation and the decline in the event rate. During the post-stimulation period from 13 December 2006 onward, a further 350 locatable events were detected up to 2 May 2007, by which time events were occurring sporadically at around one per day. In all, locations for more than 3,500 events were determined.
1949 Queen Charlotte Islands earthquake
This earthquake, larger than the 1906 San Francisco earthquake, is Canada's largest earthquake recorded by seismometers. However, the greatest earthquake in Canadian history was the 1700 Cascadia earthquake, a megathrust earthquake that occurred along the Pacific Northwest coast from Northern California to southwestern British Columbia which reached magnitude 9 on the Richter magnitude scale.