On the morning of Friday, January 19th, the Kilauea volcano went through an explosive event, causing the lava lake surface to move back and forth, like a mini-tsunami, over more than 15 minutes. Spatters – fragments of molten lava – up to about 30 cm (11.8 in) in size were hurled onto the rim of Halema‘uma‘u during the explosive events.
A rockfall at the summit lava lake caused an explosion at 7:03 a.m. HST, hurling spatter far from the crater on January 19, 2018. The rockfall agitated the lava lake surface and caused it to swing back-and-forth for at least 15 minutes. The collapse was followed by a smaller rockfall at 7:07 a.m.
Kilauea volcanologists explain that explosive events triggered by rockfalls, like those this morning, occur with no warning and are one of the reasons why the Halema‘uma‘u crater rim area remains closed to the public. The fallout from January 19th explosion would have resulted in serious injury to anyone on the impacted crater rim as spatters up to about 30 cm (11.8 in) in size were hurled onto the rim of Halema‘uma‘u. Some fragments were even thrown or blown farther downwind, reaching as far as the closed section of Crater Rim Drive in Hawai‘i Volcanoes National Park.
“Dimples” in the Pele’s hair that has accumulated on the rim of Halema‘uma‘u are evidence of ballistic impacts during today’s rockfall-triggered explosion in Kīlauea Volcano’s summit lava lake. Spatter (fragments of molten lava) blasted from the lava lake landed all around HVO’s thermal camera (HTcam) that monitors lake activity. Fortunately, the camera escaped damage.