Magnitude 1.8 - 49 miles S of Kaktovik
April 7, 2021 10:09:45 AKDT (April 7, 2021 18:09:45 UTC)
69.4432°N 144.1364°W Depth 5.1 miles (8 km)
This event has been reviewed by a seismologist
- 98 miles (158 km) N of Arctic Village
- 107 miles (173 km) E of Pump Station #2
- 114 miles (184 km) SE of Deadhorse
- 115 miles (186 km) SE of Prudhoe Bay
- 120 miles (194 km) SE of Pump Station #1
- 123 miles (199 km) E of Pump Station #3
- 148 miles (239 km) NE of Pump Station #4
- 177 miles (286 km) NW of Old Crow
- 178 miles (288 km) N of Venetie
- 193 miles (312 km) N of Chalkyitsik
- 194 miles (314 km) E of Umiat
- Magnitude type: Ml
- 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.
