Report on Krysuvik-Trolladyngja (Iceland) — 29 December-4 January 2022
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
29 December-4 January 2022
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2021. Report on Krysuvik-Trolladyngja (Iceland). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 29 December-4 January 2022. Smithsonian Institution and US Geological Survey.
63.917°N, 22.067°W; summit elev. 360 m
All times are local (unless otherwise noted)
Icelandic Meteorological Office (IMO) reported that the earthquake swarm at the Krýsuvík-Trölladyngja volcanic system was ongoing with more than 19,000 earthquakes recorded during 21-28 December. Earthquakes M 4 or above totaled 14. The number and size of the earthquakes progressively decreased during 29 December 2021 to 3 January 2022; 200 events were recorded during 0000-1535 on 3 January. The seismicity was located along the same dyke system that fed the recent eruption at Geldingadalir. The Aviation Color Code remained at Orange.
Geological Summary. The Krýsuvík-Trölladyngja volcanic system is described by the Catalogue of Icelandic Volcanoes as an approximately 50-km-long composite fissure swarm trending about N38°E, including a 30-km-long swarm of fissures, with no central volcano. It is one of the volcanic systems arranged en-echelon along the Reykjanes Peninsula west of Kleifarvatn lake. The Fagradalsfjall and Krýsuvík fissure swarms are considered splits or secondary swarms of the Krýsuvík–Trölladyngja volcanic system. Small shield volcanoes have produced a large portion of the erupted volume within the system. Several eruptions have taken place since the settlement of Iceland, including the eruption of a large basaltic lava flow from the Ogmundargigar crater row around the 12th century. The latest eruption, identified through tephrochronology, took place during the 14th century.