Seismicity observed under the Snæfellsjökull volcano

— The Snæfellsnes peninsula in western Iceland is characterized by Pleistocene volcanism dominated by alkalic magmatism across an extinct (> 6 Ma) axial rift zone of the Mid-Atlantic Ridge. Although Iceland has an extensive seismic coverage, no systematic seismic monitoring is in place on the Snæfellsnes peninsula. In this paper, we present results of a three months field campaign in the Snæfellsnes peninsula and show for the first time that the region is (micro) seismically active in the depth range of 8–15 km. We identified and located a total of 29 seismic events that occurred in close proximity of the Snæfellsjökull volcano, with most events clustering beneath the volcano in swarm sequences. We propose that seismicity is associated with fluid-induced fracturing related to one or more magmatic reservoir(s), which may be elucidated in future seismic campaigns. Our observations are the first step towards the understanding of the plumbing system of the Snæfellsjökull volcano.