Today, Portugal's Furnas volcano is a fun tourist attraction. But, a mere 395 years ago, it was the site of the nation's deadliest volcanic eruption. While there is currently magma at 5 kilometers or 3.1 miles below ground underneath a section of this Azores volcano, it is not currently a cause for concern as it has been there for some time. Today's video will discuss this volcano and its geologic history. Note: The database listed in a scientific paper by Brown, S.K., Jenkins, S.F., Sparks, R.S.J. et al. Volcanic fatalities database: analysis of volcanic threat with distance and victim classification. J Appl. Volcanol. 6, 15 (2017). https://doi.org/10.1186/s13617-017-0067-4, CC BY 4.0. was referenced in this video's title with the number of fatalities during Furnas's 1630 CE eruption. If you would like to support this channel, consider using one of the following links: (Patreon: http://patreon.com/geologyhub) (YouTube membership: https://www.youtube.com/channel/UCYeGh5VML5XPr5jYnzh3J6g/join) (Gemstone & Mineral Etsy store: http://prospectingarizona.etsy.com) (GeologyHub Merch Etsy store: http://geologyhub.etsy.com) Google Earth imagery used in this video: ©Google & Data Providers This video is protected under "fair use". If you see an image and/or video which is your own in this video, and/or think my discussion of a scientific paper (and/or discussion/mentioning of the data/information within a scientific paper) does not fall under the fair use doctrine, and wish for it to be censored or removed, contact me by email at geologyhubyt@gmail.com and I will make the necessary changes. Various licenses used in sections of this video (not the entire video, this video as a whole does not completely fall under one of these licenses) and/or in this video's thumbnail image (and this list does not include every license used in this video and/or thumbnail image): Public Domain: https://creativecommons.org/publicdomain/mark/1.0/ CC BY 4.0: https://creativecommons.org/licenses/by/4.0/legalcode Sources/Citations: [1] GUEST, J. & Pacheco, Jose & Cole, Paul & Duncan, Angus & Wallenstein, Nicolau & Queiroz, Gabriela & Gaspar, João & Ferreira, Tamyres. (2015). Chapter 9 The volcanic history of Furnas Volcano, Sao Miguel, Azores. 10.1144/M44.9. [2] J.Virgı́lio Cruz, Rui M Coutinho, M.Rosário Carvalho, Niels Oskarsson, Sigurdur R Gislason, Chemistry of waters from Furnas volcano, São Miguel, Azores: fluxes of volcanic carbon dioxide and leached material, Journal of Volcanology and Geothermal Research, Volume 92, Issues 1–2, 1999, Pages 151-167, ISSN 0377-0273, https://doi.org/10.1016/S0377-0273(99)00073-6. (https://www.sciencedirect.com/science/article/pii/S0377027399000736) [3] J.E Guest, J.L Gaspar, P.D Cole, G Queiroz, A.M Duncan, N Wallenstein, T Ferreira, J.-M Pacheco, Volcanic geology of Furnas Volcano, São Miguel, Azores, Journal of Volcanology and Geothermal Research, Volume 92, Issues 1–2, 1999, Pages 1-29, ISSN 0377-0273, https://doi.org/10.1016/S0377-0273(99)00064-5. (https://www.sciencedirect.com/science/article/pii/S0377027399000645) [4] Aguiar, S., Sandri, L., Pimentel, A. et al. Using stochastic modelling to unravel the eruptive behaviour of the active central volcanoes of São Miguel (Azores). Bull Volcanol 87, 54 (2025). https://doi.org/10.1007/s00445-025-01840-1, CC BY 4.0. [5] Source of Volcanic Explosivity Index (VEI) methodology and criteria: Newhall, C. G., and Self, S. (1982), The volcanic explosivity index (VEI) an estimate of explosive magnitude for historical volcanism, J. Geophys. Res., 87(C2), 1231–1238, doi:10.1029/JC087iC02p01231. Accessed / Read by Youtube.com/GeologyHub on Oct 5th, 2022. [6] VEIs, dates/years, composition, tephra layer name, DRE estimates, and bulk tephra volume estimates for volcanic eruptions shown in this video which were assigned a VEI 4 or larger are sourced from the LaMEVE database (British Geological Survey © UKRI), https://www2.bgs.ac.uk/vogripa/view/controller.cfc?method=lameve, Used with Permission [7] Brown, S.K., Jenkins, S.F., Sparks, R.S.J. et al. Volcanic fatalities database: analysis of volcanic threat with distance and victim classification. J Appl. Volcanol. 6, 15 (2017). https://doi.org/10.1186/s13617-017-0067-4, CC BY 4.0. This source's database was used to cite the number of fatalities the Furnas volcano caused during its 1630 CE eruption. [8] Alaska Volcano Observatory [9] University of Alaska Fairbanks, Geophysical Institute 0:00 Magma Below 0:39 Furnas Volcano 1:16 Volcano Location 2:21 Geologic History 3:11 Caldera Formation 4:23 Holocene Eruptions