RAPID: Response to the 2021 Earthquake Swarm and Volcanic Eruption in Reykjanes, Iceland

It is exceptionally difficult to capture the early phases of an eruption, especially in a remote area. The Fagradaldsfjall eruption in Iceland is unusual in that it was preceded by an earthquake swarm that lasted for nearly a month. This provided the opportunity to investigate the potential eruption site, collect high resolution (centimeter-scale) preliminary DEMs of the most probable eruption sites, generate associated DEMs and orthomosaics using UAS, as well as obtain the necessary permissions to access the area in the event of the eruption.

Consequently, when the eruption began, its opening phase and development since have been monitored. Pre-eruption surveys of valleys that are most likely to become lava flow paths are being mapped. Maps are also being constructed of the surface expression of specific seismic events to determine links between surface fracture patterns and earthquake source mechanisms.

Active lava emplacement processes are being measured to establish better constraints on effusion rates, lava emplacement dynamics, lava thermo-rheology, and lava cooling. In addition to providing information that will be useful for lava-flow hazards, the project is funding the research of a graduate student.

The 2021 earthquake swarm on the Reykjanes peninsula has generated >50,000 earthquakes since 21 February and on 3 March tremor was identified, signaling magma movement. In the following days, the magma came within 1 km of the surface and an eruption began at 8:45 pm GMT on March 19 in the hilly Krísuvík region, which is located