A scientist takes a gravity reading at a station located on the down-dropped blo

A scientist takes a gravity reading at a station located on the down-dropped block of Kīlauea caldera, which subsided as an intact structure, while a second gravity instrument (foreground) records data. Many of the preexisting gravity stations, which have been measured for years, survived Kīlauea's 2018 summit collapse. Remeasuring the stations now and comparing the data to previous results could provide information on what's happening below ground within the volcano's shallow magmatic system. USGS photo by M. Poland, 03/25/2019.