July 9, 2025 – Scientists measure gas emissions during episode 28 of the Halema‘uma‘u Kīlauea summit eruption

During episode 28 of lava fountaining during the ongoing Kīlauea summit eruption, USGS scientists approached the caldera rim to measure volcanic gas emissions with permission from Hawai‘i Volcanoes National Park. This lava fountain on the morning of July 9 was approximately 1000 feet tall (300 meters). Here, two scientists set up an FTIR (Fourier Transform Infrared Spectroscopy) instrument to analyze the gases emitted during the eruptive episode. Volcanic gas concentrations and compositions provide information about magma storage conditions, which aid in ongoing volcanic hazard assessments. USGS photo by K. Wall.