January 26, 2026 — Kīlauea episode 41 tephra crushes easily

Tephra fall from episode 41 of Kīlauea summit eruption included pieces of reticulite, frothy rocks full of bubbles made by gas within lava expanding (which drives the lava fountaining process). These pieces of rock are very lightweight and glassy, which makes them very easy to crush. The photo on the left shows a piece of reticulite that fell in Hawaiʻi Volcanoes National Park on January 24, 2026, while the photo on the right shows the same piece of reticulite after it has been stepped on. The tiny walls of all the bubbles in the honeycomb-like structure of the reticulite very easily break down into smaller ash sized particles. USGS photos by K. Mulliken.