Is Mauna Loa Active Right Now?
Mauna Loa is one of the most active volcanoes on Earth, located on the Big Island of Hawaii. It is a shield volcano that rises about 13,679 feet above sea level and is the largest active volcano by volume and area on the planet. Its most recent eruption began on November 27, 2022, and lasted until December 13, 2022, marking the first eruption since 2014. The US Hawaiian Volcano Observatory (HVO) continuously monitors Mauna Loa for signs of renewed activity, including ground deformation, seismic tremors, and gas emissions. As of the latest public data, no eruption is currently in progress, but the volcano remains at an elevated alert level due to ongoing unrest and the potential for future eruptions with little warning.
The November 2022 eruption started in the volcano's summit caldera and migrated into the Northeast Rift Zone, sending lava flows toward the Saddle Road but stopping well short of populated areas. Lava fountains reached heights of up to 200 feet, and the eruption produced significant volcanic gas emissions, including sulfur dioxide. The event was closely tracked by the HVO, which used webcams, satellite data, and ground-based sensors to provide real-time updates. The eruption was classified as a VEI 3 event, indicating a moderate scale compared to some of Mauna Loa's past eruptions. The volcano's current alert level is set by the HVO based on a combination of seismic activity, deformation patterns, and historical behavior, and it remains a focus of continuous scientific study.
What Is Mauna Loa's Eruption History and Frequency?
Major Eruptions and Recorded Activity
Mauna Loa has erupted 33 times since its first well-documented eruption in 1843, making it one of the most frequently erupting volcanoes in the world. Its eruptions typically produce fluid basaltic lava flows that can travel long distances. Notable eruptions include the 1950 event, which sent lava flows toward the village of Hoʻōpūloa, and the 1984 eruption, which approached within 4 miles of Hilo. The 2022 eruption was significant because it ended a period of quiescence that began after the 2014 eruption. Each eruption provides valuable data for scientists studying volcanic processes, magma supply rates, and the potential hazards facing communities on the Big Island.
The frequency of Mauna Loa's eruptions has averaged roughly every 5 to 6 years over the past two centuries, though the intervals can vary significantly. The volcano's long-term eruption pattern suggests that future eruptions are inevitable, but the exact timing remains uncertain. The HVO maintains a detailed record of past eruptions, including lava flow maps, eruption volumes, and duration, which is accessible to researchers and the public. Understanding this history is critical for hazard assessment and for developing emergency response plans for communities in the volcano's path, particularly those along the South Kona and Hilo coasts.
How Is Mauna Loa Monitored and What Are the Current Hazards?
Monitoring Systems and Data Sources
The USGS Hawaiian Volcano Observatory employs a network of seismometers, GPS stations, tiltmeters, and satellite-based InSAR systems to monitor Mauna Loa's activity around the clock. These instruments detect subtle changes in the volcano's shape, ground movement, and earthquake swarms that can signal magma movement beneath the surface. The HVO also measures volcanic gas emissions, particularly sulfur dioxide and carbon dioxide, to assess the potential for air quality impacts during an eruption. Data from these systems is published in daily updates and weekly