A rockfall on the east rim of the summit vent
within Kīlauea Volcano's Halema‘uma‘u Crater triggered a small explosive event at 3:51 a.m., HST, on January 8, 2016. Explosive events like this occur more frequently when the lava lake
level is relatively high, as it has been this past week—around 30-35 m (100-115 ft) below the vent rim. Rocks in the vent wall expand as they are heated by the high temperature of the lava
lake and become unstable. Sections of these unstable rocks can then collapse into the lava lake. This Quicktime movie shows today's rockfall as seen from HVO and Jaggar Museum.