- Current Update, last updated Feb 11, 2015 10:41 :
Seismicity continued to be slightly elevated; deformation patterns suggest continuing inflation over the past month.
Monitoring data through the month of January 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 Caldera remain elevated, with rates similar to that seen in previous months. Though there were no swarms on the west flank of Mauna Loa, earthquake rates remained above background with approximately 20 earthquakes occurring in the past month. All earthquakes in the past month have been small relative to earthquake sequences observed before eruptions in 1975 and 1984.
Deformation: GPS data suggest that inflation continues after a lull in December, but rates are too low to discern the whether the sources have changed. The single satellite radar interferogram available for Mauna Loa for January is ambiguous, as it is likely dominated by atmospheric effects not related to volcanic factors.
Gas: No significant changes in SO2, CO2 were recorded by the Mokuʻāweoweo Caldera gas and temperature monitors during January. Fumarole temperature continued to stabilize following the temperature anomaly that occurred between early October and late November, 2014. Temperature varied between 77 and 78 degrees C, except for a precipitation-induced decrease at the beginning of the month.
- 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