Through the thin, freshly fallen blanket of snow, the cloud-covered Bláfjöll volcanoes in southwest Iceland rise majestically above extensive lava flows, which are almost completely covered by thick cushions of moss. A landscape that seems magically peaceful at first glance, until one discovers the story of its origins. These Blue Mountains, as the name translates from Icelandic, are one of the most volcanically active hotspots in Europe. The Bláfjöll volcanoes are part of the extensive Brennisteinsfjöll volcanic system, which stretches along the tectonically active Reykjanes Peninsula. This landscape is a geological showcase of the forces that created Iceland in the first place – and continue to shape it.
The bedrock never rests here. The Reykjanes Peninsula is part of the Mid-Atlantic Ridge, which comes ashore on Iceland. Along this extensive rift in Earth’s crust, the Eurasian and North American plates drift apart by approximately three centimetres (one inch) every year – a process known as ocean-floor-spreading. As the plates move away from each other in jolts, accompanied by numerous earthquakes, hot magma constantly rises from Earth’s mantle, filling the resulting cracks and fissures and forming new crust – an endless cycle of geological formation and destruction. As soon as the magma reaches the surface, it erupts as lava and creates volcanoes.
The Bláfjöll volcanoes themselves have witnessed numerous such eruptions in the past, which have formed the lava plateau we see today. Although they have not erupted for centuries, their dormancy is deceptive. Since 2021, the Reykjanes Peninsula has been experiencing regular volcanic eruptions once again after a break of around 800 years, especially in the nearby Fagradalsfjall system and the numerous fissure eruptions of the Grindavik Fires. These eruptions mark the beginning of a new volcanic episode that could last for decades – a clear sign that the Bláfjöll area could also reactivate in the long term, as earthquake swarms have been occurring underneath them repeatedly during the last year.
On the Reykjanes Peninsula, the terrain is currently rising and falling by more then 50 centimetres (about 20 inches) within a few months. This is an expression of the rising magma and the subsequent volcanic eruptions as well as the formation of dykes, a dynamic interaction between plate tectonics and volcanism.