The 5.8-magnitude earthquake that shook Howard County Tuesday, Aug. 23 was just the latest tremor to jolt the region. While many of the earthquakes — like Tuesday's centered in Mineral, Va., about 125 miles south of Columbia — originated elsewhere, 22 since 1900 have started in Howard County. Those quakes, and their epicenters and dates:

• Columbia, on Route 29 just north of Route 32: 18 (15 in 1993, three in 1996)

• Patapsco Valley State Park, near Bloedes Dam west of downtown Ellicott City: 2 (one in 1993, one in 1996)

• Columbia, along Route 108 just north of Route 175: 1 in 1993

• Ellicott City, where Route 40 meets Route 29: 1 in 1993

Source: Howard County Office of Emergency Management