An explosion at Kilauea summit’s Halemaumau crater vent Wednesday night blasted incandescent rock into the air and onto the crater’s rim, geologists said this afternoon. The second Halemaumau explosion in three weeks also enlarged the vent by 15 to 30 feet.
(Click above photo to enlarge.)
The new explosion occurred at 11:08 p.m. (Hawaii time) Wednesday, but geologists apparently held the news for most of today.
The new explosion was smaller in magnitude than Halemaumau’s March 19 blast—which geologists at the Hawaiian Volcano Observatory did not see, since it occurred in the early morning hours at a time when they were not watching the summit as carefully.
But with Halemaumau activity now closely monitored 24/7, geologists witnessed all of last night’s event—which blasted rock onto the crater rim, more than 230 feet above the vent.
HVO geologists exploring the rim just after sunrise found lava spatter and rocks. The spatter melted plastic pans they’d placed on the rim to collect material from Halemaumau’s ongoing steam and ash eruption.
Hawaii Volcanoes National Park was closed to the public when last night's eruption occurred. The park reopened this morning, after shutting down for two days due to high levels of sulfur dioxide in the air.
Big Island Civil Defense, meanwhile, said residents of Pahala—19 miles south and downwind of the Halemaumau vent—had reported falling ash last night. HVO geologists are suggesting that the ash could have been tiny fragments of rock pulverized by the explosion.
Photo of Halemaumau vent on 4/6/08 (left) and today, courtesy of USGS