Products, processes, and implications of Keanakāko‘i volcanism, Kīlauea Volcano, Hawai‘i

The Keanakāko‘i Tephra offers an exceptional window into the explosive portion of Kīlauea’s recent past. Once thought to be the products of a single eruption, the deposits instead formed through a wide range of pyroclastic activity during an ~300 yr period following the collapse of the modern caldera in ca. 1500 CE. No single shallow conduit or vent system prevailed during this period, and most of the deposits are confined to distinct sectors around the caldera. Vent position shifted abruptly and repeatedly throughout this time period. This combination of circumstances, influenced by prevailing wind direction, led to rapid lateral changes in the stratigraphy. We define and describe 12 units, several of which are subdivided into subunits or beds, and place them in a framework that reflects volcanologic processes as well as temporal succession.