Abstract
Fogo volcano erupted in 2014–2015 producing an extensive lava flow field in the summit caldera that destroyed two villages, Portela and Bangaeira. The eruption started with powerful explosive activity, lava fountains, and a substantial ash column accompanying the opening of an eruptive fissure. Lava flows spreading from the base of the eruptive fissure produced three arterial lava flows. By a week after the start of the eruption, a master lava tube had already developed within the eruptive fissure and along the arterial flow. In this paper, we analyze the emplacement processes based on observations carried out directly on the lava flow field, remote sensing measurements carried out with a thermal camera, SO2 fluxes, and satellite images, to unravel the key factors leading to the development of lava tubes. These were responsible for the rapid expansion of lava for the ~7.9 km length of the flow field, as well as the destruction of the Portela and Bangaeira villages. The key factors leading to the development of tubes were the low topography and the steady magma supply rate along the arterial lava flow. Comparing time-averaged discharge rates (TADR) obtained from satellite and Supply Rate (SR) derived from SO2 flux data, we estimate the amount and timing of the lava flow field endogenous growth, with the aim of developing a tool that could be used for hazard assessment and risk mitigation at this and other volcanoes.
Highlights
When an effusive eruption starts, the maximum distance that a flow can travel can be estimated based on the measured peak effusion rate [1,2,3,4]
The general shape of a complex lava flow field is defined by a few arterial lava flows generally displaying aa texture, with its outline modified by secondary lava flows normally having a pahoehoe surface [2,9,10]
Given that satellite images only detect surface emplacement of lava, and that SO2 flux instead is related to the total magma volume stored in the source region [32] and feeding the eruption, the difference between the two should give an estimation of the magma intruded within the lava flow field and responsible for its inflation and supplying lava tubes
Summary
When an effusive eruption starts, the maximum distance that a flow can travel can be estimated based on the measured peak effusion rate [1,2,3,4]. Given that satellite images only detect surface emplacement of lava, and that SO2 flux instead is related to the total magma volume stored in the source region [32] and feeding the eruption, the difference between the two should give an estimation of the magma intruded within the lava flow field and responsible for its inflation and supplying lava tubes. The 1995 lava flow field is from [39]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
