Aloha, it's your weekly Volcano Minute, brought to you by the USGS Hawaiian Volcano Observatory.

Kīlauea’s recent lava‑fountaining episodes may feel dramatic and new, but the volcano’s geologic record tells us they’re part of a long-term pattern. Similar high lava fountains have erupted inside Kaluapele, the Kīlauea caldera, several times over the past 500 years.

Earlier eruptions you may know—Puʻuʻōʻō in the 1980s, Maunaulu in 1969, and Kīlauea Iki in 1959—all began with impressive fountains. At Kīlauea Iki, those fountains even built Puʻupuaʻi, a large tephra cone that still stands today on the caldera rim. While few cones exist along the modern caldera rim, geologic deposits show that major fountaining events also occurred around the years 1500, 1650, and again in the early 1800s.

These layers—collectively called the Keanakākoʻi Tephra—give scientists clues about past eruptions. One deposit, known as Unit B, consists of extremely bubbly reticulite and appears to have come from fountains more than 1,900 feet high. Another, from around 1650, spread scoria as far as the coast, suggesting a plume that reached jet‑stream heights. Two younger pumice-rich layers, units K1 and K2, record additional fountain events in the early 1800s.

All of this shows that today’s eruption style in Halemaʻumaʻu is not unprecedented. By studying these past deposits alongside the ongoing activity, scientists gain a clearer picture of how Kīlauea behaves—and how it may change in the future.

Mahalo for listening, I’m Katie Mulliken and this was your weekly volcano minute brought to you by the USGS Hawaiian Volcano Observatory.