The Supereruption in Hong Kong; The High Island Caldera

Hong Kong was once the site of a supereruption. In fact, today the modern city literally sits on a portion of this volcano, specifically its magma chamber which can be today seen via numerous granitic rock formations such as Lion Rock. What this magma created was an eruption so large that it left a massive 18 kilometer wide depression in the ground which was nealy 2 kilometers deep. And, this early Cretaceous period eruption left behind more than 20,000 hexagon shape columns which have a peculiar origin. Today's video will discuss this caldera through the perspective of a geologist, which is known as the High Island Caldera.

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Sources/Citations:
[1] Fang, W.; Gou, G.R.; Cheung, L.T.O.; Fok, L.; Chow, A.S.Y.; Zhang, K. An Investigation of Willingness to Pay for Geopark Management and Conservation: A Case Study of Geotourists in the Greater China Region. Resources 2024, 13, 24. https://doi.org/10.3390/resources1302..., CC BY 4.0.
[2] U.S. Geological Survey
[3] Alaska Volcano Observatory
[4] University of Alaska Fairbanks, Geophysical Institute
[5] Alaska Division of Geological & Geophysical Surveys

0:00 Hong Kong Caldera
1:33 Tilted Caldera
2:31 Geologic Setting
3:24 The Supereruption Occurs
4:37 Formation of Hexagonal Columns