Mauna Loa , Hawai : inflation of a magma reservoir complex beneath the summit.

Mauna Loa , Hawai :  inflation of a magma reservoir complex beneath the summit.

Activity Summary:
Mauna Loa is not erupting. No significant change in seismicity was recorded beneath the volcano in the past week, remaining elevated above long-term background levels. In the past week, earthquakes at Mauna Loa occurred mostly beneath the volcano’s upper Southwest Rift Zone at depths less than 5 km (3 mi). Global Positioning System (GPS) measurements continue to show deformation related to inflation of a magma reservoir complex beneath the summit and upper Southwest Rift Zone.

 

TOP: Mauna Loa weekly earthquake rates between 2010 and September 17, 2015. Blue bars indicate the number of earthquakes that were located by the USGS Hawaiian Volcano Observatory seismic network. Earthquakes of all magnitudes are plotted. Subtle increases in earthquake rates started in mid-2013, while more obvious changes in rates started in 2014.
BOTTOM: Change in distance across Mauna Loa’s summit caldera between 2010 and September 17, 2015. Blue dots indicate the relative distance between two stations that span the summit caldera of Mauna Loa, shown in the map on the upper left. Sustained extension across the caldera started in mid-2014. This extension is one of the indicators of magma infilling a complex reservoir system beneath the summit and upper Southwest Rift Zone.

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.

January 08, 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. GVP.

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