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.
2009–19 Oklahoma earthquake swarms
A large earthquake of magnitude 5.0 occurred on the evening of November 6, with an epicenter located one mile (2 km) west of Cushing in Payne County. It was the fifth-largest earthquake recorded in state history. Following the quake, images of damage to buildings in Cushing began to surface on Twitter and local news reported that the Cushing Fire Department had been inundated with calls of damage, but no injuries had been reported. The Cimarron Tower assisted-living apartment building incurred damage, with part of the building collapsing, and all of its elderly residents were evacuated. Additional damage was inflicted on the First Presbyterian Church. Cushing Public Schools canceled Monday classes to allow for damage to be evaluated. The largest oil storage hub in the United States, located in Cushing, did not report any damage. According to the city manager of Cushing, 40 to 50 structures received damage.