October 3, 2023 — Kīlauea GPS campaign

A GPS survey benchmark is being occupied on the Southwest Rift Zone of Kīlauea. The metal disk on the ground beneath the tripod is the benchmark, which is cemented to the lava flow surface. Each year during the Kīlauea GPS campaign survey, a high-precision GPS unit is centered over the benchmark to collect data. The height of the GPS unit on the tripod is accounted for when calculating how much the benchmark has moved vertically and horizontally over the past year. USGS photo by A. Ellis.