August 2, 2024—Sulfur Cone gas monitoring maintenance

On August 2,2024, Hawaiian Volcano Observatory Gas Scientists flew via helicopter to the Sulfur Cone Multi-Gas instrumentation site on Mauna Loa's Southwest Rift Zone, which is at an elevation of 3,430 meters (11,240 feet) above sea level. Their mission was to replace the Multi-Gas instrument, which had been at this location since September 2022, with a newly calibrated instrument and to replace the batteries which power the site. On average, batteries at HVO monitoring stations are typically changed approximately every 5 years, with continuously monitoring Multi-Gas instruments being replaced about every 2 years. This photo looks down the axis of Mauna Loa's Southwest Rift Zone towards Ocean View Estates, with Sulfur Cone itself in the foreground. What may look to some like snow covering the ground all around this site, is—in reality—elemental Sulfur being deposited due to the constant degassing of sulfur gases here. USGS photo by M. Cappos.