A U.S. Geological Survey scientist aims the viewfinder of an infrared spectrometer to measure the chemistry of volcanic gas on the last day of the Nāpau eruption Sept. 20, 2024. (U.S. Geological ...
and sulfur dioxide. Researchers said those were the primary hazards of concern. The previous episode earlier this month lasted more than 22 hours with lava emerging from its north and south vents.