Magnitude 1.7 - 27 miles E of Pump Station #4
August 12, 2019 19:07:31 AKDT (August 13, 2019 03:07:31 UTC)
68.4398°N 148.292°W Depth 9.0 miles (14 km)
This event has been reviewed by a seismologist
- 31 miles (50 km) SE of Pump Station #3
- 71 miles (115 km) S of Pump Station #2
- 74 miles (119 km) W of Arctic Village
- 86 miles (139 km) NE of Wiseman
- 90 miles (145 km) E of Anaktuvuk Pass
- 96 miles (155 km) NE of Coldfoot
- 110 miles (178 km) NW of Venetie
- 115 miles (186 km) SE of Umiat
- 121 miles (196 km) S of Deadhorse
- 125 miles (202 km) S of Prudhoe Bay
- 126 miles (204 km) S of Pump Station #1
- 249 miles (403 km) N of Fairbanks
- Magnitude type: Ml2
- Event type: earthquake
Tectonic Setting of the Brooks Range
Seismicity in the Brooks Range is characterized by intraplate earthquakes associated with mountain building and crustal reorganization. A broad earthquake band extends from northeast of the Brooks Range toward the Beaufort Sea. Earthquake source mechanisms comprise a mixture of strike-slip and normal faulting events, indicative of north-northwest compression and northeast extension. A magnitude 6.4 earthquake on August 12, 2018 located 43 miles (69 km) south of Kaktovik was the largest earthquake ever recorded north of the Brooks Range. It produced an energetic aftershock sequence that continues to this day. In 2019, a vigorous swarm sequence began in the Purcell Mountains. More than 9,000 earthquakes have been recorded as part of this swarm through the end of 2021, including five earthquakes with magnitudes larger than 5. At present, this swarm continues, though at a decreased activity level.