Despite being widely associated with active volcanoes, lava lakes are in fact quite rare. Yet, a few of them still do exist, and can be quite large. Today's video discusses each of these lava lakes, shows a size comparison, and some interesting facts relating to how they form. It also discusses one method of spotting "fossil" ancient lava lakes in old igneous rock outcroppings. Thumbnail Photo Credit: U.S. Geological Survey, Hawaiian Volcano Observatory, Public Domain This video's thumbnail image shows a 2018 photo of Kilauea's summit lava lake. 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 2.0: https://creativecommons.org/licenses/by/2.0/legalcode Sources/Citations: [1] U.S. Geological Survey [2] George T. Faust, "Joint Systems in the Watchung Basalt Flows, New Jersey", Geological Survey Professional Paper 864-B, U.S. Geological Survey 0:00 Lava Lakes 1:22 Size Comparisons 2:06 Lava Lake Compositions 3:13 Erebus Crystals 4:17 Ancient Lava Lakes