Earthquake swarm September/October 2022 on Disko Island, West Greenland

During 25 days in September and August 2022, the island of Disko in central west Greenland experienced a swarm of around 200 small earthquakes, ranging from ML 1.0 to ML 3.1. The majority of the earthquakes were concentrated on a small peninsula measuring 15 x 25 km. We have not received any felt reports, with  the closest inhabited area is approximately 20 km away. The island of Disko is part of the Palaeogene North Atlantic province. Swarms has been observed on and around Disko Island earlier, but not in the same place as the September/October 2022 swarm. In 2010, 27 earthquakes were detected in an area  around 20 km to the east [1], and in 2016 a swarm of over 250 earthquakes occurred following three mb 4.5+ earthquakes. These earthquakes occurred offshore and south of Disko Island, 60 km to the SSE [2]. The coverage with seismic stations is Greenland is sparse, with distances between stations in hundreds of km, but since 2019 three additional stations have been in operation in central west Greenland due to monitoring for landslide events, enabling better locations. The closest station to the swarm is GDH, at 60 km distance. The largest earthquakes in the swarm could be observed at a distance of more than 1600 km.

• Larsen, T.B., et al., Earthquake swarms in Greenland. Geological Survey of Denmark and Greenland (GEUS) Bulletin, 2014. 31: p. 75-78.
• Dahl-Jensen, T., P.H. Voss, and T.B. Larsen, [S01-4-01] Recent earthquakes at Disko Island, Greenland, with focal mechanisms in IAG-IASPEI Joint Scientific Assembly. 2017: Kobe, Japan.