Mauna Loa is not erupting. Seismicity remains elevated above the long-term background level, but no significant changes were recorded over the past week. Deformation related to inflation of a magma reservoir beneath the summit and upper Southwest Rift Zone continues, with inflation recently occurring mainly in the southwestern part of the magma storage complex.
The plot below shows changes in distance across Moku??weoweo, Mauna Loa’s summit caldera, since 1974, as measured by continuously recording GPS stations. Increases in distance often indicate increased pressure in the magma reservoir beneath the summit area (inflation).
The large extensions associated with the 1975 and 1984 eruptions were caused by magma rising from the summit reservoir to the volcano’s surface and accompanied by increased rates of seismicity. During the 1984 eruption, the summit area contracted and subsided rapidly as magma left the reservoir to feed the eruption along the northeast rift zone. When the eruption stopped, the summit magma reservoir immediately began to re-inflate. The inflation ceased in 1993; distances across the caldera decreased and the ground surface subsided from then until 2002.
In May 2002, years of slow contraction and subsidence abruptly changed to extension and uplift. GPS measurements and remote imaging revealed patterns of ground-surface motion that indicated renewed influx of magma into a complex shallow magma system below. The extension and uplift rates increased dramatically in July 2004, as a swarm of very deep earthquakes started. The high rates of inflation slowed dramatically in 2005 and continued to slow until completely ceasing by mid-2013. Inflation resumed in mid-2014.
May 24, 2016. Mauna Loa , Hawai :
19°28’30” N 155°36’29” W,
Summit Elevation 13681 ft (4170 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
Source : HVO