Magnitude 6.4 - 55 miles SW of Kaktovik
August 12, 2018 06:58:53 AKDT (August 12, 2018 14:58:53 UTC)
69.5762°N 145.291°W Depth 9.8 miles (15 km)
This event has been reviewed by a seismologist
- 79 miles (128 km) E of Pump Station #2
- 86 miles (139 km) SE of Deadhorse
- 86 miles (139 km) SE of Prudhoe Bay
- 92 miles (149 km) SE of Pump Station #1
- 101 miles (163 km) N of Arctic Village
- 101 miles (163 km) NE of Pump Station #3
- 129 miles (209 km) NE of Pump Station #4
- 166 miles (269 km) E of Umiat
- 180 miles (291 km) N of Venetie
- 189 miles (306 km) NE of Anaktuvuk Pass
- 193 miles (312 km) NE of Wiseman
- Magnitude type: Mw
- Event type: N/A
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.
