Annual Mauna Loa GPS Survey—2021

GPS campaign survey stations high on the flanks of Mauna Loa offer expansive views of neighboring volcanoes. From this station located west of Mauna Loa summit, Hualālai volcano is visible. Most Mauna Loa GPS campaign survey sites have been occupied every year since 1996, whereas less active volcanoes Hualālai and Haleakalā are surveyed every 3–5 years. USGS photo by S. Conway.