Annual GPS survey on Mauna Loa

Over the past several weeks, HVO geophysicists have been conducting the annual high-precision Global Positioning System (GPS) survey of Mauna Loa, which supplements HVO's continuous GPS monitoring stations. The annual GPS surveys provide information on vertical and horizontal deformation, informing HVO about the volume changes within subsurface magma reservoirs at Mauna Loa. This station was located on the north flank of Mauna Loa, with Mauna Kea (hugged by clouds on its east side) visible in the background. USGS photo by S. Conway.