OKLAHOMA GEOLOGICAL SURVEY CANADIAN COUNTY EARTHQUAKE SWARM 2002 Sep 21-22 The largest earthquake of the swarm was located by arrival times at four seismographs: 2002 Sep 22 20:44:36 GMT (3:44:36PM CDT) at 35.435 degrees N. latitude, 98.023 degrees W. longitude, depth restrained at 5.0 kilometers. This epicenter is 5.5 miles NW of Union City, Canadian County, Oklahoma. Generally all earthquakes of a swarm like this one occur along the same limited fault plane, It is likely that all of these are located near 35.4N, 98.0W.