November 21, 2025 — Cold lava sampling on floor of Halema‘uma‘u

On November 21, USGS Hawaiian Volcano Observatory scientists collected solid lava samples from the floor of Halema‘uma‘u crater at the summit of Kīlauea. All sampling in this area, which is significant to native Hawaiian communities, is done with permission from Hawai‘i Volcanoes National Park. This "cold sampling," distinct from sampling molten lava flows, sometimes requires the lava rock to be broken, exposing its interior structure. Here, one of the scientists is breaking the rocks down to a size that could be easily transported with them in a helicopter out of a crater. USGS photo by M. Warren.