June 17, 2023 — Gas measurements at Halemaʻumaʻu

A USGS gas scientist uses an infrared spectrometer to collect gas chemistry measurements from the plume in Halemaʻumaʻu crater at the summit of Kīlauea on Saturday, June 17, 2023. Unlike some gas instrumentation that relies on ultraviolet light from the sun—which means measurements can only be collected during daylight hours—the infrared spectrometer allows for measurements at night. USGS photo by P. Nadeau.