Today (1-February-2022) at 00:05 UTC an earthquake with magnitude of Mw3,7 took place close to Húsafell. This earthquake was felt in Reykjavík. This earthquake swarm is ongoing, it is slow moving and often stops A second earthquake with magnitude Mw3,0 took place at 01:15 UTC. During the last 48 hours a total of 107 earthquakes have happened in Húsafell area.
Largest known earthquake in this area has a magnitude of 5,5 in the year 1974. That is all I know about this earthquake, that earthquake was also slightly more north then current swarm. Why this earthquake activity is happening is unclear since there are not any known volcanoes in this area or earthquake faults. There is a low (as in degrees of hot water) hydrothermal area in this area and recent news articles have suggested that this earthquake activity might be connected to that area. That is at best speculation and nothing has been proved so far. The existence of this low hydrothermal area shows that magma is in the crust in this area at shallow depth and has been for a while. For hydrothermal area to form, both cracks in the crust needs to be open and magma needs to reach 1 to 2 km up in the crust to warm up ground water in the crust.