Magnitude 3.5 - 44 miles SW of Kaktovik
August 4, 2020 06:01:43 AKDT (August 4, 2020 14:01:43 UTC)
69.5399°N 144.3692°W Depth 9.9 miles (16 km)
This event has been reviewed by a seismologist
- 102 miles (165 km) N of Arctic Village
- 102 miles (165 km) E of Pump Station #2
- 106 miles (171 km) SE of Deadhorse
- 106 miles (171 km) SE of Prudhoe Bay
- 112 miles (181 km) SE of Pump Station #1
- 120 miles (194 km) NE of Pump Station #3
- 146 miles (236 km) NE of Pump Station #4
- 183 miles (296 km) N of Venetie
- 185 miles (299 km) NW of Old Crow
- 189 miles (306 km) E of Umiat
- 200 miles (324 km) N of Chalkyitsik
- 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.