Scientists measure gas from Halemaʻumaʻu crater - June 9, 2023

USGS Hawaiian Volcano Observatory gas specialists uses a FTIR (Fourier-transform infrared spectroscopy) spectrometer at the new eruption in Halema‘uma‘u crater that began on June 7, 2023. The FTIR measures the composition of the gases being emitted during the eruption by measuring how the plume absorbs infrared energy. The plume being generated by the ongoing eruption is sulfur-dioxide (SO₂) rich, but also contains water vapor, carbon dioxide, and halogen gases such as HCl and HF.