Gas monitoring station in Moku‘āweoweo, Mauna Loa

The former gas monitoring station in Moku‘āweoweo, Mauna Loa's summit caldera. Power and telemetry components of the station are to the right in the image, with solar panels. The gas sensors themselves were housed in the black box toward the lower left of the image. Note that the white, yellow, and orange discoloration of the dark ground surface is a result of volcanic gases reacting with the darker rocks. USGS photo by K. Calles.