Evidence for the existence of the Powers Caldera is based largely on a fault scarp mantled by the Uwēkahuna Ash Member within Uwēkahuna Bluff and exposure of the Uwēkahuna Ash Member in the modern Kīlauea Caldera wall at an elevation more than lower than its occurrence beneath a surface flow near the Tree Molds. This implies that a large depression existed in the summit area of Kīlauea prior to deposition of the Uwēkahuna Ash Member. The boundaries of the Powers Caldera have been inferred by connecting concentric caldera fractures and faults about outside the modern Kīlauea Caldera rim. It is estimated that the Powers Caldera had a depth of at least .