Global Positioning System (GPS) survey of Mauna Loa recently completed
Recently, HVO geophysicists completed the annual high-precision Global Positioning System (GPS) survey of Mauna Loa. The annual survey supplements HVO's continuous GPS monitoring stations and provides information on vertical and horizontal deformation of the ground surface. These measurements inform HVO about the volume changes within subsurface magma reservoirs at Mauna Loa. This photo shows a survey benchmark being occupied on the west flank of Mauna Loa with clear views of Hualālai. USGS photo by S. Conway.