Magnitude 3.5 - 47 miles S of Kaktovik
October 20, 2019 21:21:59 AKDT (October 21, 2019 05:21:59 UTC)
69.4858°N 144.3162°W Depth 4.5 miles (7 km)
This event has been reviewed by a seismologist
- 99 miles (160 km) N of Arctic Village
- 103 miles (167 km) E of Pump Station #2
- 109 miles (176 km) SE of Deadhorse
- 109 miles (176 km) SE of Prudhoe Bay
- 115 miles (186 km) SE of Pump Station #1
- 120 miles (194 km) NE of Pump Station #3
- 145 miles (235 km) NE of Pump Station #4
- 179 miles (290 km) N of Venetie
- 182 miles (295 km) NW of Old Crow
- 190 miles (308 km) E of Umiat
- 196 miles (317 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.