April 21, 2023 — HVO Geologist on the floor of Halema‘uma‘u crater, in Kaluapele (Kīlauea caldera)

A geologist from the Hawaiian Volcano Observatory (HVO) selects a sampling site on the floor of Halema‘uma‘u crater during the morning of April 21, 2023. The geologist is standing near the eastern rim of the lava lake that was active in the western portion of Halema‘uma‘u crater during the January–March, 2023, eruption. The mound next to the geologist is a spatter rampart; spatter ramparts form when bits of molten lava travel through the air and accumulate on the ground surface, forming a mound-like feature. Crews that visit these dynamic locations have extensive training and wear specialized personal protective equipment, such as helmets and gas masks, to keep them safe. USGS image by L. Gallant.