The Identification and Evolution of Lava Tubes within the 2021 Fagradalsfjall Lava Flow Field as a Potential Planetary Analogue

• Main Author: Kimberly Jean Hutchinson 1997-
• Other Authors: Háskóli Íslands
• Format: Master Thesis
• Language: English
• Published: 2023
• Subjects: Jarðfræði (námsgrein); Reykjanes; Iceland
• Online Access: http://hdl.handle.net/1946/44549

The identification of lava tubes and the conditions in which they form are an important subject as it relates to volcanic hazards, lava transport systems, planetary exploration, archaeology, speleology, and multiple other fields of study. The 2021 basaltic eruption of Fagradalsfjall volcano on the Reykjanes Peninsula in Iceland ended a ~800-year hiatus of volcanic activity in the area. It was well monitored with near real-time photogrammetric surveys using satellite and airborne remote sensing data including orthomosaics with resolutions of 30×30 cm/pixel and digital elevation models with resolutions of 2×2 m/pixel. We used this database to study the evolution of lava tubes by manually mapping flow morphologies in a GIS environment at an approximate scale of 1:1000. The morphology of the lava field changed significantly over time. March 19–April 5 (Phase 1) included the start of the eruption and was dominated by two active vents that infilled Geldingadalir valley. Braided incandescent lava channels were primarily observed going to the NE of Geldingadalir valley but breakouts along the edge of the inflating lava flow field were also observed. April 5–April 27 (Phase 2) had multiple active vents and was dominated by far-reaching incandescent channels that extended the flow field into Meradalir valley and Syðri-Meradalur valley. During April 27–June 28 (Phase 3), one active vent was established for the rest of the eruption. The morphology of the lava field was characterized by the formation of a lava pond in Syðri-Meradalur valley and the continued expansion of the lava flow field into Nátthagi valley. June 28–September 2 (Phase 4) was characterized by episodic activity at the vent which created discontinuous lava flows that primarily flowed into Meradalir and Syðri-Meradalur. During September 2–September 18 (Phase 5), a pause in activity from September 2–11 was followed by the formation of a lava pond in the N of Geldingadalir valley from September 11–15. An upwelling zone in the middle of Geldingadalir appeared ...