Mauna Loa

Mauna Loa is the largest active volcano on Earth by volume and surface area, forming the southern bulk of the Big Island from the ocean floor to a summit of 4,169 meters. Its broad, gently sloping shield profile is visible from much of the Big Island and presents a stark contrast to the sharp-flanked Mauna Kea to the north. The summit observatory, operated by NOAA since 1956, has recorded the longest continuous atmospheric CO₂ measurements in history.