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Volcano Updates

The Hawaiian Volcano Observatory issues updates and other types of Mauna Loa notifications as activity warrants.

Alert Level: NORMAL, Color Code: GREEN 2023-05-04 22:25:06 UTC

U.S. Geological Survey
Thursday, May 4, 2023, 12:25 PM HST (Thursday, May 4, 2023, 22:25 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

No significant activity was detected at Mauna Loa volcano during the past month. The number of detected earthquakes remained at background levels and most events were smaller than M2.0. The largest earthquake for Mauna Loa over the past month was a M3.0 event on April 2 northwest of Moku`aweoweo. 

Data from Global Positioning System (GPS) instruments on Mauna Loa indicate slow inflation as magma replenishes the summit reservoir system. 

Gas and temperature data from a station on the Southwest Rift Zone showed no significant changes over the past month.

HVO continues to monitor the volcano closely 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 north 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.


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