The United States is expected to have a major volcanic eruption in the upcoming weeks to months. This eruption is expected to occur from Mount Spurr. Mount Spurr is the closest active volcano to Anchorage in Alaska, and the last two times it erupted the city received 1/8"-1/4" of ash. A magma intrusion is ongoing at this volcano, and while there are no imminent signs of an eruption yet, the Alaska Volcano Observatory stated that a similar magnitude explosive eruption to Spurr's 1953 and 1992 eruptions (VEI 4) is the most likely outcome of its ongoing unrest. Thumbnail Photo Credit: Frame grab from a video by Mitchell, Mitch, Alaska Volcano Observatory / U.S. Geological Survey, https://avo.alaska.edu/image/view/196425. This image was then modified by cropping the image, brightening the image in darker & shadowed areas, increasing the image's white point, decreasing the image's original color temperature, increasing the image's color saturation, and overlaying it with text and GeologyHub made graphics (the image border & the GeologyHub logo). Note: For some viewers this thumbnail image is mirrored horizontally (left became right & right became left) with the same text overlay not mirrored over it. If you would like to support this channel, consider using one of the following links: (Patreon: http://patreon.com/geologyhub) (Gemstone & Mineral Etsy store: http://prospectingarizona.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] Alaska Volcano Observatory [3] McGimsey, Robert G., Neal, Christina A., Riley, Colleen M., 2001, Areal Distribution, Thickness, Mass, Volume, and Grain Size of Tephra-Fall Deposits from the 1992 Eruptions of Crater Peak Vent, Mt. Spurr Volcano, Alaska: U.S. Geological Survey Open-File Report 01-370, 38 pp., https://pubs.usgs.gov/of/2001/0370/. Note: This source was used to cite the 1992 ash/tephra thickness maps. [4] VEIs, dates/years, composition, & 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 [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] University of Alaska Fairbanks, Geophysical Institute [7] Alaska Division of Geological & Geophysical Surveys [8] Waythomas, Christopher F.; Nye, Christopher J., 2001, Preliminary Volcano-Hazard Assessment for Mount Spurr Volcano, Alaska: U.S. Geological Survey Open-File Report 01-482, 40 pp., https://pubs.usgs.gov/of/2001/0482/. Note: This source was used to trace the hazard zone maps of Mount Spurr. [9] Koulakov, I., Smirnov, S.Z., Gladkov, V. et al. Causes of volcanic unrest at Mt. Spurr in 2004–2005 inferred from repeated tomography. Sci Rep 8, 17482 (2018). https://doi.org/10.1038/s41598-018-35453-w, CC BY 4.0. Note: This source was used to cite the peak number of monthly earthquakes during the 1996-1998 & 2004-2006 volcanic unrest episodes at Mt. Spurr along with the amount of magma the 2004-2006 unrest was triggered by. [10] Gardner, Cynthia & Cashman, Katharine & Neal, Christina. (1998). Tephra-fall deposits from the 1992 eruption of Crater Peak, Alaska: implications of clast textures for eruptive processes. Bulletin of Volcanology. 59. 537-555. 10.1007/s004450050208. [11] 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 0:00 Mt. Spurr Unrest 2:09 Similar Unrest Episodes 3:19 4 Possibilities 4:01 Typical Eruptions 4:42 1992 Ashfall 5:22 Hazard Maps