A major magnitude 7.1 earthquake struck Malaysia offshore of the island of Borneo. Yet instead of causing severe damage and a tsunami, no damage of any kind occurred. This earthquake was centered not in the crust but the very lowermost levels of our planet's upper mantle. So, how did this earthquake originate in the mantle? This video will answer this question, along with how it relates to a now inactive plate boundary. This video's thumbnail image displays a photograph of Kota Kinabalu in Malaysia. 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] U.S. Geological Survey [2] Mao, G.L., Ferrand, T.P., Li, J. et al. Unsupervised machine learning reveals slab hydration variations from deep earthquake distributions beneath the northwest Pacific. Commun Earth Environ 3, 56 (2022). https://doi.org/10.1038/s43247-022-00377-x. CC BY 4.0. [3] Charles S. Hutchison, The North-West Borneo Trough, Marine Geology, Volume 271, Issues 1–2, 2010, Pages 32-43, ISSN 0025-3227, https://doi.org/10.1016/j.margeo.2010.01.007. (https://www.sciencedirect.com/science/article/pii/S0025322710000277) [4] Wei-Nan Liu, Chun-Feng Li, Jiabiao Li, Derek Fairhead, Zuyi Zhou, Deep structures of the Palawan and Sulu Sea and their implications for opening of the South China Sea, Marine and Petroleum Geology, Volume 58, Part B, 2014, Pages 721-735, ISSN 0264-8172, https://doi.org/10.1016/j.marpetgeo.2014.06.005. (https://www.sciencedirect.com/science/article/pii/S0264817214002128) [5] Keenan, Timothy & Encarnación, John & Buchwaldt, Robert & Fernandez, Dan & Mattinson, James & Rasoazanamparany, Christine & Luetkemeyer, P.. (2016). Rapid conversion of an oceanic spreading center to a subduction zone inferred from high-precision geochronology. Proceedings of the National Academy of Sciences. 113. 10.1073/pnas.1609999113. [6] Chen, W.-H., Yan, Y., Carter, A., Clift, P. D., Huang, C.-Y., Yumul, G. P., Jr., et al. (2024). Evolution of arc-continent collision in the southeastern margin of the South China Sea: Insight from the Isugod Basin in central-southern Palawan. Tectonics, 43, e2023TC008078. https://doi.org/10.1029/2023TC008078 [7] Ohuchi, T., Higo, Y., Tange, Y. et al. In situ X-ray and acoustic observations of deep seismic faulting upon phase transitions in olivine. Nat Commun 13, 5213 (2022). https://doi.org/10.1038/s41467-022-32923-8. CC BY 4.0. 0:00 M7.1 Malaysia Earthquake 1:22 Deep Focus Earthquakes 2:24 Earthquake Trends 3:44 Phase Transitions 4:41 Deep Slab Faulting