Active lava surface meets stagnant surface in Halema‘uma‘u lava lake

On October 19, 2021, the lava lake in Halema‘uma‘u crater—at the summit of Kīlauea—showed surface activity by crustal foundering, where warm lava flows on top of older, cooler surface crust that then sinks back into the lake. A 1 m (3 ft) high edge separates the active surface to the west from the stagnant surface to the east. This photo was taken at 2:15 p.m. HST. USGS photo by J. Schmith.