March 11, 2023 — USGS Geophysicists perform annual gravity survey of Kīlauea
March 11, 2023 — USGS Geophysicists perform annual gravity survey of KīlaueaUSGS scientist, Mike Poland, measures gravity using a gravimeter on the caldera floor of Kīlauea. Measurements of gravity can be used to determine how mass is distributed beneath a volcano. At Kīlauea, the Hawaiian Volcano Observatory (HVO) performs routine microgravity surveys to monitor volcanic activity and to determine changes in gravity. USGS photo by A.