2025 Annual Campaign GPS measurements in progress

USGS Hawaiian Volcano Observatory staff are conducting the annual Mauna Loa GPS campaign. During the survey, GPS instruments are deployed at established benchmarks so that their recorded positions can be compared with those from previous years to discern small changes in ground deformation associated with volcanic activity. Temporary GPS receivers and antennas are placed on tripods centered over benchmarks, which serve as a reference point for centering of the antenna. The equipment is left in place to collect data for a couple of days at each site. USGS photo by A. Ellis.