March 15, 2023 — USGS Geophysicists perform annual gravity survey of Kīlauea

USGS geophysicists take gravity measurements on the dropped-down block of Kīlauea as part of annual monitoring. Annual microgravity surveys are crucial in confirming whether ongoing uplift or subsidence is caused by magma intrusion or withdrawal. Scientists conduct these surveys using small, shoebox-sized instruments called relative gravimeters that can measure a change in the force of gravity to one-in-one billionth of the force you feel every day. USGS photo by A. Ellis.