Mauna Loa GPS Survey Enhances Volcano Monitoring

The U.S. Geological Survey Hawaiian Volcano Observatory (HVO) has completed its 2026 annual GPS campaign on Mauna Loa, deploying 22 benchmark stations across the island. Combined with a permanent network of daily‑position GPS stations, the high‑precision data expands the geodetic coverage and refines the long‑term deformation model for the volcano.

Mauna Loa, the world’s largest active volcano, has erupted 34 times since 1843, most recently from 27 November to 10 December 2022, when lava flowed nearly 12 mi and covered about 16.5 sq mi. By tracking ground motions—outward movement indicating inflation and magma buildup, inward movement indicating deflation—HVO can better assess potential hazards and communicate warnings to nearby communities. Stable benchmarks also support mapping, imagery calibration, and model validation for ongoing research.

The campaign’s findings improve scientists’ ability to detect magma reservoir changes beneath Mauna Loa and enhance preparedness for future eruptive activity.