gas-driven explosion
Detailed Description
On the morning of May 9, 2018, a large rockfall in "Overlook crater" within Halema‘uma‘u at the summit of Kīlauea triggered a gas-driven explosion that sent an ash plume several thousand feet skyward. Phreatic (steam-driven) explosions can create larger ash plumes; the 1924 explosions sent ash plumes up to 20,000 feet high.
Sources/Usage
Public Domain.