Report on Reykjanes (Iceland) — 29 April-5 May 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 29 April-5 May 2020
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on Reykjanes (Iceland). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 29 April-5 May 2020. Smithsonian Institution and US Geological Survey.
63.85°N, 22.566°W; summit elev. 140 m
All times are local (unless otherwise noted)
IMO reported that uplift detected in the Thorbjorn area decreased in the beginning of April and stopped later in the month. Seismicity, which had occurred across three main volcanic systems: Eldey, Reykjanes-Svartsengi, and Krýsuvík, had significantly decreased. These data indicated that the injection of magma beneath Thorbjorn had stopped, though there were indications of deformation over a larger area. On 4 May the Aviation Color Code was lowered to Green.
Geologic Background. The Reykjanes volcanic system at the SW tip of the Reykjanes Peninsula, where the Mid-Atlantic Ridge rises above sea level, comprises a broad area of postglacial basaltic crater rows and small shield volcanoes. The submarine Reykjaneshryggur volcanic system is contiguous with and is considered part of the Reykjanes volcanic system, which is the westernmost of a series of four closely-spaced en-echelon fissure systems that extend diagonally across the Reykjanes Peninsula. Most of the subaerial part of the system (also known as the Reykjanes/Svartsengi volcanic system) is covered by Holocene lavas. Subaerial eruptions have occurred in historical time during the 13th century at several locations on the NE-SW-trending fissure system, and numerous submarine eruptions dating back to the 12th century have been observed during historical time, some of which have formed ephemeral islands. Basaltic rocks of probable Holocene age have been recovered during dredging operations, and tephra deposits from earlier Holocene eruptions are preserved on the nearby Reykjanes Peninsula.