At 9:17 a.m. HST, another weak ash plume rose from the Overlook Vent in Halema‘uma‘u crater, producing a slightly more energetic and darker plume. This second plume lacked the pink altered ash that was in the earlier plume, apparently consisting of more unaltered (therefore darker) rock fragments. This plume also was probably caused by rockfall into the deepening vent, not related to groundwater and steam-driven explosions. Photo taken Friday, May 11, 2018 courtesy of U.S. Geological Survey