Wednesday, July 31, 2013

Mauna Loa - Is the Next Eruption Near?

Mauna Loa in Hawaii is the world largest volcano by volume. Rising from the sea floor to its summit, it is one of the largest mountains in the world as well, from foot to summit, being about 56,000 ft... many times taller than even Mt. Everest! It also happens to be Hawaii's most active volcano, although you wouldn't know it given its recent slumber. It actually erupts more often than Kilauea, last having erupted about the same time that Kilauea started its current eruption, in 1984, a year after Kilauea started its current eruption. This eruption cause massive lava flows that paved over towns/villages, and caused a lot of property damage (hence the big islands ridiculous insurance prices).

Mauna Loa has erupted 33 times since 1843 (and many many times before) making it one of the worlds most active and massive volcanoes.

Mauna Loa has been mostly quiet since its last eruption. The volcano currently has some active fumeroles, hot springs, and still-degassing areas from the last eruption, but that may be about to change, as HVO has detected heightened seismicity and inflation of a shallow magma reservoir. Could Mauna Loa be gearing up for another eruption? It is probable, as Mauna Loa is 'overdue' for an eruption.

HVO's current reporting of Mauna Loa indicates that deformation has been mostly dominated by slow south-easterly motion of its south flank (toward the active Kilauea volcanic complex), but more recently, increased inflation of about 1cm/year at the summit caldera, which does indicate new magma injection, and a possible precursor to an eruption in the near future. It is definitely worth keeping an eye on Mauna Loa.

While it is highly unlikely that an eruption of Mauna Loa would cause any human casualties, the potential for massive amounts of property damage, and damage to ecosystems on the island is high. During the 1984 eruption, vast swaths of land were covered by lava, and in some areas, houses were built on these lava flows, which have a high likelihood of getting hit by a lava flow again. Any areas that did not have a lava flow would be at risk due to lava pooling or gravity drawing in a flow.

The next eruption of Mauna Loa would likely be quite a sight to behold. Most volcanic eruptions in Hawaii do not generate pyroclastic flows, or anything more than fast or slow moving pahoehoe lava flows, fissure eruptions, however there have been cases of crater forming eruptions that do prove a bit dangerous. I for one will be keeping a close eye on Mauna Loa, as the eruption will be spectacular, no matter what the mountain does. And the fact that Hawaii has some of the best webcam coverage of its volcanoes means that many would get to see the eruption take place in real-time! Stay tuned!