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Scientists (in orange flight suits) hike toward one of HVO's monitoring stations within Kīlauea caldera. The tripod supports a GPS antenna that provides information on deformation of the volcano. The doghouse-like structure (foreground) houses a gravimeter, which measures changes in subsurface mass over time. Together, these two instruments keep continuous watch on changes in surface deformation and the gravity field, both of which are useful indicators of future magmatic activity at Kīlauea. USGS photo by M. Poland, 03/25/2019.
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.
A closer view of a gravity reading at a station located in the south part of Kīlauea caldera. When repeated over time, gravity measurements can detect changes in subsurface mass that might not be detectable by other monitoring methods. Scientists track this data because the changes could be related to magma movement within the volcano. USGS photo by M. Poland, 03/20/2019.
