In early 2025, 30,000+ earthquakes struck adjacent to Greece's Island of Santorini. We now know why. It was not purely tectonic, but rather caused by a large intrusion of magma beneath the ocean floor. Today's video discusses what we now know 9.5 months after the seismic crisis and aforementioned magma intrusion ended. Note: It is safe in the opinion of YouTube.com/GeologyHub to visit Santorini. In fact, I'd recommend it. Beautiful place. 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 [email protected] 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] Isken, M.P., Karstens, J., Nomikou, P. et al. Volcanic crisis reveals coupled magma system at Santorini and Kolumbo. Nature 645, 939–945 (2025). https://doi.org/10.1038/s41586-025-09525-7, CC BY 4.0. [2] Konstantinou, K.I. Magma chamber evolution during the 1650 AD Kolumbo eruption provides clues about past and future volcanic activity. Sci Rep 10, 15423 (2020). https://doi.org/10.1038/s41598-020-71991-y, CC BY 4.0. [3] B.G. McVey, E.E.E. Hooft, B.A. Heath, D.R. Toomey, M. Paulatto, J.V. Morgan, P. Nomikou, C.B. Papazachos; Magma accumulation beneath Santorini volcano, Greece, from P-wave tomography. Geology 2019;; 48 (3): 231–235. doi: https://doi.org/10.1130/G47127.1 [4] Browning, J., Drymoni, K. & Gudmundsson, A. Forecasting magma-chamber rupture at Santorini volcano, Greece. Sci Rep 5, 15785 (2015). https://doi.org/10.1038/srep15785, CC BY 4.0. [5] Kathleen Cantner, Steven Carey, Paraskevi Nomikou, Integrated volcanologic and petrologic analysis of the 1650AD eruption of Kolumbo submarine volcano, Greece, Journal of Volcanology and Geothermal Research, Volume 269, 2014, Pages 28-43, ISSN 0377-0273, https://doi.org/10.1016/j.jvolgeores.2013.10.004. (https://www.sciencedirect.com/science/article/pii/S0377027313002953) [6] Nomikou, P. et al. Post-eruptive flooding of Santorini caldera and implications for tsunami generation. Nat. Commun. 7, 13332 doi: 10.1038/ncomms13332 (2016). CC BY 4.0. [7] Karstens, J., Crutchley, G.J., Hansteen, T.H. et al. Cascading events during the 1650 tsunamigenic eruption of Kolumbo volcano. Nat Commun 14, 6606 (2023). https://doi.org/10.1038/s41467-023-42261-y, CC BY 4.0. [8] U.S. Geological Survey 0:00 Santorini's Early 2025 EQ Swarm 1:02 July 2024 Intrusion 1:36 2025 Magma Dike Intrusion 2:52 Historical Santorini Eruptions 3:48 Kolumbo Discussion