Magnitude 3.9 - 45 miles S of Kaktovik
April 20, 2020 07:13:41 AKDT (April 20, 2020 15:13:41 UTC)
69.5018°N 144.1524°W Depth 8.8 miles (14 km)
This event has been reviewed by a seismologist
- 101 miles (163 km) N of Arctic Village
- 107 miles (173 km) E of Pump Station #2
- 112 miles (181 km) SE of Deadhorse
- 112 miles (181 km) SE of Prudhoe Bay
- 118 miles (191 km) SE of Pump Station #1
- 124 miles (201 km) NE of Pump Station #3
- 149 miles (241 km) NE of Pump Station #4
- 180 miles (291 km) NW of Old Crow
- 182 miles (295 km) N of Venetie
- 194 miles (314 km) E of Umiat
- 197 miles (319 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.