Kīlauea summit gravity survey - September 23, 2020

An HVO geophysicist takes a gravity measurement at a benchmark near a continuous gravimeter (inside hutch). The continuous gravimeter takes gravity measurements once per second and relays the data via radio back to HVO. During the gravity survey on September 23, 2020, HVO scientists took measurements at multiple locations on the floor of Kīlauea caldera. By comparing the measurements made at these benchmarks with survey data from previous dates, HVO scientists can estimate the change of mass beneath the instrument. USGS photo by I. Johanson.