- Current Update, last updated Aug 4, 2015 14:38 :
Monitoring data through the month of July 2015:
Seismicity: Seismicity at Mauna Loa remains elevated in several parts of the volcano. Earthquake rates on the Upper Southwest Rift Zone (Sulfur Cone) and Mokuʻāweoweo Crater remain elevated, with over 150 located earthquakes occurring in July. There was a swarm on the west flank of Mauna Loa, approximately 100 located earthquakes. All earthquakes in the past month have been small relative to earthquake sequences observed before eruptions in 1975 and 1984.
Deformation: The Mauna Loa GPS network recorded modest net inflation over the month of July, with very little inflation in the second half of the month. Modeling of the pattern of motions since this current episode of inflation started in the summer of 2014 suggests at least two inflating reservoirs--a spherical reservoir near the southeast wall of the summit caldera, and a tabular body that lies beneath the caldera and upper Southwest Rift Zone.
Gas: No significant changes in SO2 and CO2 were recorded by the continuous fumarole monitor during July, 2015. The fumarole temperature sensor leveled off a decline that began on 08 May. Since that time, the temperature has decreased from 82 to about 78.5 degrees.
- 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: NORMAL Aviation Color Code: GREEN