Another giant pano of the volcano. Kīlauea's most recent eruption began on September 29, 2021. Structurally, Kīlauea has a large, fairly recently formed caldera at its summit and two active rift zones, one extending 78 mi east and the other 22 mi west, as an active fault of unknown depth moving vertically an average of 0.1 to 0.8 in per year.