Magnitude 1.8 - 23 miles E of Pump Station #3
August 12, 2019 15:39:00 AKDT (August 12, 2019 23:39:00 UTC)
68.9103°N 147.9384°W Depth 7.5 miles (12 km)
This event has been reviewed by a seismologist
- 41 miles (66 km) S of Pump Station #2
- 49 miles (79 km) NE of Pump Station #4
- 82 miles (132 km) NW of Arctic Village
- 89 miles (144 km) S of Deadhorse
- 93 miles (150 km) S of Prudhoe Bay
- 95 miles (154 km) S of Pump Station #1
- 108 miles (175 km) E of Umiat
- 110 miles (178 km) NE of Anaktuvuk Pass
- 118 miles (191 km) NE of Wiseman
- 128 miles (207 km) NE of Coldfoot
- 134 miles (217 km) SW of Kaktovik
- 282 miles (457 km) N of Fairbanks
- 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.
