Kīlauea caldera gas mapping—August 10, 2021

During the gas survey of Kīlauea caldera, HVO scientists walk transects in a grid-like pattern. As they traverse, the MultiGAS instruments that they are carrying on their backs measure the amount of carbon dioxide (CO₂), sulfur dioxide (SO₂), water vapor (H₂O), and hydrogen sulfide (H₂S). The measurements will be used to create a map showing the areas of the caldera floor where specific volcanic gasses are being emitted and their concentrations. USGS photo by K. Mulliken on August 10, 2021.