More on the history of Kilauea's explosive eruptions

1924 Kilauea eruption, source not known, perhaps USGS
found on this website.

While searching for information on the progress of the eruption at Puu Oo, Hawaii, this morning, I stumbled across more information on explosive eruptions of Kilauea. According to Decker and Christiansen, 1984, explosive eruptions comprise about 1% of the prehistoric and historic eruptions.  An event in 1790 deposited most of the Keanakakoi Formation (pumice, vitric ash, and rocks) that is more than 10 m deep around Kilauea's summit area.  An eruption about 1500 years ago deposited the Uwekahuna Ash, and there are two or three similar older units under it. The Pahala Ash on the south flank of Kilauea contains records of many explosive eruptions from about 25,000-10,000 years ago.  There is evidence of older explosive eruptions as well, but they are difficult to date.  Decker and Christiansen say that the "dangerous explosive eruptions probably relate to sudden disruptions of equilibrium between subsurface water and shallow magma bodies, triggered by major lowering of the magma column." (Their article is in Explosive volcanism: inception, evolution, and hazards, 1984,published by the National ResearchCouncil of the U.S. Geophysics Study Board.

There is an excellent and somewhat entertaining article on the 1924 explosions of Kilauea here, a USGS HVO site.