Magnitude 1.5 - 25 miles E of Pump Station #4
August 20, 2019 21:14:23 AKDT (August 21, 2019 05:14:23 UTC)
68.4917°N 148.4078°W Depth 8.6 miles (13 km)
This event has been reviewed by a seismologist
- 26 miles (42 km) SE of Pump Station #3
- 67 miles (108 km) S of Pump Station #2
- 78 miles (126 km) W of Arctic Village
- 87 miles (141 km) NE of Wiseman
- 88 miles (142 km) E of Anaktuvuk Pass
- 97 miles (157 km) NE of Coldfoot
- 111 miles (179 km) SE of Umiat
- 115 miles (186 km) NW of Venetie
- 117 miles (189 km) S of Deadhorse
- 122 miles (197 km) S of Prudhoe Bay
- 122 miles (197 km) S of Pump Station #1
- 253 miles (410 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.