Eruption
Update
Eruption
Summary
Hazards
History

When Kilauea began to form is not known, but various estimates are 300,000-600,000 years ago. The volcano has been active ever since, with no prolonged periods of quiescence known. Geologic studies of surface exposures, and examination of drillhole samples, show that Kilauea is made mostly of lava flows, locally interbedded with deposits of explosive eruptions. Probably what we have seen happen in the past 200 years is a good guide to what has happened ever since Kilauea emerged from the sea as an island perhaps 50,000-100,000 years ago.

Lava Erupts from Kilauea's Summit and Rift Zones

Throughout its history Kilauea has erupted from three main areas, its summit and two rift zones. Geologists debate whether Kilauea has always had a caldera at the summit or whether it is a relatively recent feature of the past few thousand years. It seems most likely that the caldera has come and gone throughout the life of Kilauea.

The summit of the volcano is high because eruptions are more frequent there than at any other single location on the volcano. However, more eruptions actually occur on the long rift zones than in the summit area, but they are not localized, instead constructing ridges of lower elevation than the summit. Eruptions along the east and southwest rift zones have build ridges reaching outward from the summit some 125 km and 35 km, respectively.

Most eruptions are relatively gentle, sending lava flows downslope from fountains a few meters to a few hundred meters high. Over and over again these eruptions occur, gradually building up the volcano and giving it a gentle, shield-like form. Every few decades to centuries, however, powerful explosions spread ejecta across the landscape. Such explosions can be lethal, as the one in 1790 that killed scores of people in a war party near the summit of Kilauea. Such explosions can take place from either the summit or the upper rift zones.

Future of Kilauea

The foreseeable future of Kilauea looks much like the past. Continued effusive eruptions will fill the caldera, heighten the summit, and build the rift zones--over and over and over again. Sporadic explosions will cause destruction but hopefully not loss of life. We cannot tell how much larger Kilauea will grow or when it will stop, but it will surely continue to erupt through the rest of human history.

Pu`u `O`o - Kupaianaha eruption

• Summary, January 1983 - 2000
• Kalapana covered by lava, 1990

Earlier eruptions

• The 1960 Kapoho Eruption
• The 1959 summit eruption at Kilauea Iki Crater

Other information

• Simplified geologic map of summit caldera