Fagradalsfjall: A Deep Dive into Iceland's Reawakened Peninsula
In March 2021, after weeks of intense earthquakes, the ground opened in a valley on Iceland's Reykjanes Peninsula and lava began to flow. The Fagradalsfjall eruption was the first on the peninsula in roughly eight centuries, and it marked the start of a new volcanic era for the region near Iceland's capital. Because it was gentle, photogenic, and remarkably easy to reach, it became one of the most watched and most visited eruptions in modern history.
The Reykjanes Peninsula awakens
The Reykjanes Peninsula is the place where the Mid-Atlantic Ridge rises from the sea and crosses onto land, making it one of the few spots on Earth where a spreading plate boundary is visible above water. For about 800 years the peninsula had been volcanically quiet. The events that began in 2021 signalled that this dormancy had ended, the start of what scientists believe may be a prolonged period of activity along the ridge.
The 2021 eruption in Geldingadalir
The first eruption broke out in the valley of Geldingadalir, near the mountain Fagradalsfjall, on 19 March 2021. It began modestly, with lava welling up from a short fissure, then concentrated into a single vent that built a growing cone and fed lava flows across the surrounding valleys. The eruption was effusive and relatively calm, producing rivers and ponds of glowing basalt rather than dangerous explosions or ash clouds.
A spectacle for everyone
What made Fagradalsfjall extraordinary was its accessibility. The eruption site lay only a short drive from Reykjavik and the international airport, reachable by a few hours' hike. Tens of thousands of people walked out to watch lava fountains and glowing flows at remarkably close range, in a setting that was monitored and managed for safety. Few eruptions in history have been witnessed in person by so many people, and it transformed public engagement with Iceland's volcanism.
Continued eruptions in 2022 and 2023
Fagradalsfjall was not a single event. Further eruptions followed in the same area in 2022 and 2023, each opening new fissures and producing fresh lava flows. These repeated episodes confirmed that the magmatic system beneath the peninsula was actively recharging, and they gave scientists an extraordinary opportunity to study the rhythms of a reawakening volcanic region almost in real time.
The shift toward Grindavik
The activity later migrated along the peninsula toward the town of Grindavik and the area around the famous Blue Lagoon geothermal spa. Beginning in late 2023, intense magma movement and new fissures threatened the town directly, leading to evacuations and the construction of protective barriers. This phase underlined that the Reykjanes reawakening, however beautiful at Fagradalsfjall, carries real risks for the communities and infrastructure of the densely settled southwest.
Why this eruption matters scientifically
The Reykjanes eruptions offer a rare chance to observe a rift-zone volcanic system springing back to life. Scientists have tracked the magma's journey from depth to surface in unprecedented detail, refining their understanding of how eruptions on spreading boundaries are fed and forecast. The lessons learned here apply to volcanic rifts worldwide and to the long-term management of risk in southwest Iceland.
Living with a new volcanic era
For Icelanders, the awakening of Reykjanes is a defining development. The region hosts much of the country's population, its main airport, and critical geothermal infrastructure. Authorities now plan for a future in which eruptions may recur for decades, balancing the wonder of accessible lava with the need to protect towns, roads, and power supplies from an unpredictable landscape.
Explore on the map
Fagradalsfjall and the Reykjanes eruptions mark a newly active chapter in Iceland's volcanic story, alongside Hekla, Katla, and the great fissure systems of the highlands. Explore them on the interactive map — filter by country to see Reykjanes among Iceland's volcanoes and to follow the Mid-Atlantic Ridge as it crosses the island.