View is from the Crater Rim Drive across Keanakako`i Crater toward the southeast. Only 35 m deep today, the crater was nearly 4 times deeper (120 m) when surveyed in 1886. Early Hawaiians collected hard, very fine-grained and glassy basalt from the deep crater to make sharp cutting tools (knives, adzes, and spear points), but lava erupted in 1877 from a vent within the crater buried the quarry site.
An eruptive fissure opened at the base of the southwest wall of Kaenakako`i on July 19, 1974 (reddish area at edge of shadow). Shortly thereafter a fissure opened north of the crater ( view #20) and farther west on the caldera floor ( view #18). The 3-day eruption was preceded by a sudden deflation of the summit area and an intense earthquake swarm beneath the caldera.