- Current Update, last updated Jul 14, 2015 06:38 :
Monitoring data through the month of June 2015:
Seismicity: Seismicity at Mauna Loa remains elevated in several parts of the volcano, however activity has been lower than in previous months. Earthquake rates on the upper Southwest Rift Zone (Sulfur Cone) and Mokuʻāweoweo Crater remain elevated, with nearly 100 located earthquakes occurring in June. Though there were no swarms on the west flank of Mauna Loa, earthquake rates remained above background with approximately 17 earthquakes occurring in June. 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 a resumption of inflation during early to mid June, after an approximately month-long lull. It is too early to establish the exact rate and pattern of inflation, but so far, the predominant average motions during June are similar to average motions since this current episode of inflation started in the summer of 2014. Preliminary modeling of the long-term pattern 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 fumaroles monitor during June, 2015. The fumarole temperature sensor continued to record a decline that began on 08 May. Since that time, the temperature as decreased from 82 to about 79 degrees by the end of June.
- 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