- Current Update, last updated Oct 8, 2015 10:58 :
On Thursday, September 17, the Volcano Alert Level and Aviation Color Code for Mauna Loa was elevated to Advisory/Yellow based on long-term trends in both earthquake and deformation monitoring data.
Activity Summary: Mauna Loa is not erupting. The seismicity rate is elevated above background, though at a lower weekly rate than reported in mid- to late-summer. Earthquakes occurred beneath Mauna Loa’s upper Southwest Rift Zone and upper west flank at depths less than 13 km (8 miles). Deformation data are still consistent with inflation of magma reservoirs beneath Mauna Loa’s summit and upper Southwest Rift Zone.
- Volcanic History Overview: Massive Mauna Loa shield volcano rises almost 9 km above the sea floor to form the world's largest active volcano. Flank eruptions are predominately from the lengthy NE and SW rift zones, and the summit is cut by the Mokuaweoweo caldera, which sits within an older and larger 6 x 8 km caldera. Two of the youngest large debris avalanches documented in Hawaii traveled nearly 100 km from Mauna Loa; the second of the Alika avalanches was emplaced about 105,000 years ago (Moore et al. 1989). Almost 90% of the surface of the basaltic shield volcano is covered by lavas less than 4000 years old (Lockwood and Lipman, 1987). During a 750-year eruptive period beginning about 1500 years ago, a series of voluminous overflows from a summit lava lake covered about one fourth of the volcano's surface. The ensuing 750-year period, from shortly after the formation of Mokuaweoweo caldera until the present, saw an additional quarter of the volcano covered with lava flows predominately from summit and NW rift zone vents.
- Location: Hawaii and Pacific Ocean, HI
Elevation: 4170 m
Recent Eruption: 1984
- Hazard Assessments: Mullineaux, Donal Ray; Peterson, Donald W., 1974, Volcanic hazards on the Island of Hawaii, Open-File Report 74-239.
- Link to monitoring data: Recent Earthquakes in Hawaii Page
Volcanic Alert Level: ADVISORY Aviation Color Code: YELLOW