The disturbances that began on October 24 on the Reykjanes Peninsula in Iceland have significantly intensified on Friday, November 10. Initially concentrated around the Svartsengi geothermal power plant and the renowned Blue Lagoon, these disruptions have now expanded slightly east of this area, following a northeast/southwest direction that intersects the town of Grindavik perfectly. Strong earthquakes have shaken its residences throughout the night. Consequently, a state of emergency has been declared, leading to the evacuation of the town, including the tourist zone of the Blue Lagoon, where earthen mounds are being constructed to safeguard the area.
The three eruptions since 2021 on the Reykjanes Peninsula, situated in a desolate and seemingly low-risk zone, may just be a gentle prelude to what can be termed the “Reykjanes fires.” After affecting the Blue Lagoon area for about fifteen days, approximately 3 kilometers north of the town of Grindavik and behind Mount Þorbjörn concerning it, seismic activity and deformation markedly intensified on November 10, shifting eastward. Over 20,000 earthquakes had already been recorded since October 24, and numerous tremors began occurring about 2 kilometers east of the Svartsengi geothermal power plant. Throughout the day, these tremors followed a northeast/southwest alignment, intersecting the town of Grindavik.
Consequently, the 4,000 residents of this small town south of the Reykjanes Peninsula experienced continuous shaking on the nights of November 10 to 11. Between 4:00 PM and 7:00 AM local time, over 300 magnitude-3 earthquakes were recorded, including around thirty with a magnitude exceeding 4 and two surpassing 5. Furthermore, the deformation in the area is remarkable, with some GPS stations displacing more than one meter horizontally and nearly 20 centimeters vertically in just a few hours. This is a substantial and noteworthy occurrence.
A State of Emergency Declared
The alignment of the earthquakes, their relative shallowness, and the significant deformation of the ground in this sector undeniably attest to the establishment of a vertical magmatic conduit at this level, known as a dyke, after several days of rather horizontal magmatic intrusion, known as a sill! The magma is thus very close to the surface. And while the unrest seems to have eased this morning, an eruption in Grindavik, further north, or even out to sea is quite likely.
Faced with this threat, the Icelandic authorities have ordered a state of emergency. Grindavik has been evacuated. Route 43, which passes over the dyke and was damaged yesterday, was closed. The aviation alert has been upgraded to orange. Finally, the Blue Lagoon and the nearby geothermal power station have also been evacuated. And although the troubles seem to be receding somewhat from this area, construction of an earth mound has begun to protect these important infrastructures. Eventually, it could reach 4 kilometers in length, with a height of 6 to 8 meters! The Blue Lagoon and its outdoor hot tubs are particularly popular with tourists. But above all, because the adjoining geothermal power station, which releases its mineral-rich waters with undeniable dermatological benefits, produces hot water and electricity for the inhabitants of the Reykjanes peninsula – a total of 21,000 households.