The first eruption in Mt. Fagradalsfjall started on March 19th, 2021 at 8:45 PM after an increased seismic activity on the Reykjanes peninsula for over a year, dating back to January 2020. The eruption was steady in the valley of Geldingadalir for about 6 months, attracting numerous visitors and was officially declared over in December 2021 after being quiet since September.
An eruption started again in Mt. Fagradalsfjall, in the valley of Meradalir on August 3rd 2022. The fissures opened only 1 km north of the previous eruption site. The eruption lasted up to 3 weeks.
The third eruption in three years started on the 10th of July at 16:40 and is still ongoing.
These events were unusual, compared to the background activity in the area over the last decades.
Periods of rifting and volcanism occur at intervals of 800-1000 years on the Reykjanes Peninsula, alternating with periods of earthquake episodes occurring at intervals of a few tens of years. The latest eruption was the Reykjanes Fires in 1210-1240 AD, where eruptive fissures within both the Reykjanes and the Eldvörp-Svartsengi volcanic systems were active, producing extensive lava flows.
Read more about the eruption: The Icelandic Met Office
Read more about volcanic sites: The Icelandic Environmental Agency