A M=4.3 quake struck the town of Waynoka, OK. The quake resulted from sudden slip on a strike-slip fault, similar to the two M=4.7 quakes that struck over the past 17 days, but this one was deeper, at 10-12 km (6-7 mi). All of the larger quakes stuck along a 100 km (60 mi) northeast trend. This quake and its predecessors were likely triggered by deep fluid injection, but at 12 km, this quake stuck far below the injection depth, which might indicate that the fluids are infiltrating to considerable depths.
