Between mid-May and early August, 2018, the depth of Halema‘uma‘u more than tripled and its diameter more than doubled as magma
from Kīlauea's shallow summit reservoir moved into the lower East Rift Zone. Evidence of subsidence is visible in this video, taken during an early morning helicopter overflight on August 6, 2018. Cracks and down-dropped blocks of the caldera
floor have slumped into Halema‘uma‘u. At the base of the steep crater walls are piles of talus (rock fragments) shaken loose during previous summit collapse events. Areas of persistent steaming within the crater, in the vicinity of the former lava lake
, are also visible.