
06/15/2025
A crater becomes a caldera... In May of 2018, after 68 total collapse events at Kilauea Volcano's summit -- each one generating an earthquake of Magnitude 5.3 or above on a daily basis -- the dust finally settled and Halema'uma'u had more than doubled in size, with its diameter now at 1 X 1.3 km. With the geological definition of a caldera being "a collapse feature greater than 1 km that forms above an underlying magma chamber", Halema'uma'u Crater had become a caldera, nested inside of Kilauea Caldera. It's official name, however, would remain "Halema'uma'u Crater" so as to avoid confusion. I've had people try to correct me when I refer to Halema'uma'u as a caldera, sometimes shouting at me in ALL CAPS to show how incensed they are -- so to them I say you should know your stuff before hitting that Caps Lock key! 😄
I put this comparison together using an aerial shot (public domain) by the Hawaii County Civil Defense from May 2018 displayed above a satellite image from Google Maps of Kilauea's summit before the collapse.