Thursday, October 25, 2012

Lava Lake At Kilauea Rises To Record Levels

One of the lava lakes at Hawaii's Kilauea volcano has risen to record levels, spilling onto the crater floor, and giving scientists a really epic show. Video posted on NBC.com shows some nice shots of the action. According to NBCnews.com and HVO, the lava lake at Halema'uma'u crater, the larger of the two main craters of Kilauea as well as the summit crater, the lava lake inset in the rim of the Halema'uma'u crater has overflowed to the crater floor. This is the first time since Halema'uma'u crater exploded in 2008 that the lava lake has overflowed the rim.

The lava lake is inset in the rim of the crater, and was formed in a large ash producing eruption in 2008. This event was preceded by harmonic tremor and uplift of the area, and was witnessed by Hawaiian volcano Observatory volcanologists.

The current theory is that the magma system at Kilauea is re-pressurizing, following a large deflation event that occurred when a fissure opened up West of Puʻu ʻŌʻō crater, which drained the magma lake at the summit, and caused the collapse of the crater floor at Puʻu ʻŌʻō which lowered the crater floor significantly, and quickly. This event was also caught on camera. Since then, the magma pressure, and inflation has been occurring at Kilauea.

While NBC's Brian Williams incorrectly (or rather, stated out of context) in the video that Kilauea has "Been active since 2008", the eruption has actually been going on at Kilauea since December of 1983, when eruptions resumed after a decade or so of dormancy. Neighboring Mauna Loa and Kilauea volcanoes were erupting simultaneously from March 24-April 15, 1984, which destroyed neighborhoods in the Kalapana area, and neared the town of Hilo.

Kilauea is one of the world's most active volcanoes, and the current eruption is one of the longest running historical eruptions of our time. Indeed, the activity on Kilauea is rivaled by only a few volcanoes, such as Mt. Etna in Sicily, and perhaps Piton de la Fournaise on Reunion Island, a French territory. It's neighbor, Mauna Loa is the largest volcano by volume on the planet earth, rising from sea floor to summit, it is larger than Mt Everest, and also a very active volcano. While it has not erupted since the early 1980's, slow inflation, and motion of the SE flank is an early indication that it will erupt in the future.

All of the Hawaiian islands have a volcanic past, due to a mantle plume hotspot that travels slowly under the crust, occasionally popping through. While Mauna Loa and Kilauea are the newest volcanoes in the Hawaiian chain that are above sea level, to the S of the Big Island, another, younger volcano, Loihi, is expected to break the surface of the ocean and either add on to the Big Island's landmass, or create a brand new Hawaiian island in the next 10,000 years. While not as active as Kilauea or Mauna Loa, the motion of the hotspot will one day retire the volcanic activity on the Big Island, and Loihi will assume the role of the most active Hawaiian volcano. 

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