Alert Level: NORMAL, Color Code: GREEN 2026-01-03 02:42:49 UTC
HAWAIIAN VOLCANO OBSERVATORY MONTHLY UPDATE
U.S. Geological Survey
Friday, January 2, 2026, 4:42 PM HST (Saturday, January 3, 2026, 02:42 UTC)
MAUNA LOA (VNUM #332020)
19°28'30" N 155°36'29" W, Summit Elevation 13681 ft (4170 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
Mauna Loa seismic activity diminished by 40%, mostly from the lull in earthquake production in the beginning of the month. There was a relatively short-lived (< 1 day) activity that elucidated the (pre-2022 eruption) northwest cluster on 2025-12-17. Earthquake production rates increased, later in the month, under the caldera and upper-SWRZ. A total of 94 earthquakes were detected beneath Mauna Loa's summit region in the December reporting period, while the prior month had 147 earthquakes. Data from Global Positioning System (GPS) instruments on Mauna Loa show a lower inflation beneath the summit compared to the previous six months. These rates are normal as the volcano recovers from the 2022 eruption and magma replenishes the reservoir system. Recent data indicate that the center of deformation has shifted to the southern caldera region, indicating refilling of a south caldera magma chamber.
Gas and temperature data from a station on Mauna Loa's Southwest Rift Zone indicate these values are at background levels, with little change relative to previous months.
HVO continues to closely monitor Mauna Loa and will issue another update in one month, or earlier, should conditions change significantly.
Background: Mauna Loa is the largest active volcano on our planet and covers half of the Island of Hawaiʻi. Eruptions tend to produce voluminous, fast-moving lava flows that can impact communities on the east and west sides of the island.
Mauna Loa eruptions typically start at the summit and, within minutes to months of eruption onset, can migrate into either the Northeast or Southwest Rift Zone, or radial vents on the northwest flank. Since its first well-documented eruption in 1843, the volcano has erupted 34 times with intervals between eruptions ranging from months to decades. Mauna Loa erupted most recently in 2022.
More Information:
This notice contains volcanoes not displayed here: Hualalai (NORMAL/GREEN), Haleakala (NORMAL/GREEN), Mauna Kea (NORMAL/GREEN), Kama'ehuakanaloa (UNASSIGNED/UNASSIGNED).
The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawaiʻi and American Samoa.
CONTACT INFORMATION:
askHVO@usgs.gov
Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes
