Thursday, April 5, 2012

Living on an active volcano island

Vog (volcanic smog), created by the gasses and ashes spewing from Kilauea Volcano tends to collect on the southwest side of Hawaii Island. Most days we get up early and get a dose of sunshine before the Vog starts to float inland and rise up the mountainside in Kona. This week the Vog has been so thick that it feels like the sun did not rise. The sounds of traffic and air conditioners are muted by the heavy air and the ocean and the sky merge into a single shade of gray. Hualalai Volcano, which rises behind Kailua-Kona town, is hidden behind a thick cover.   We study the Volcano through a variety of web links and wonder if there is more ash in the air these days or if the change in season has modified the direction of the wind.

We watch the grayish-blue cloud roiling out of Halema’uma’u Vent from a CAM set up by the USGS. We know that if the plume is heading to right on the screen it means Vog is coming our way. If the plume is bent away from the screen, we may have sunshine and clear skies in Kona the next day or two. At night we watch the eerie red emitting from the growing lava lake within Halema’uma’u on the camera.

We study the “tilt” events carefully recorded on graphs by the scientists at the HVO and know now that “deflation events” mean the lava is subsiding and “inflation events” mean the lava is surging, often spewing from Pu’u O’o vent down toward the ocean.  We study the USGS seismic map dotted with earthquake events  where the island is shifting and shuddering.

In Spring of 2008, the latest episode of this active volcano began.  Before 2008, there were 5 to 10 “tilt” events a year. There were 64 in 2009 and more every year since.  In the first three months of 2012, there have already been 37 “tilt events” measured from surging lava, more than ever recorded.   The island has had over 40 earthquakes in the past two weeks, the biggest a 4.9. The gas plume emissions from the Volcano contain sulfur dioxide, measured at 400 tonnes a day last week, and ash.

Though the dangers of tainted air, shaking earth, collapsing lava shelves,  and lava flows are very real, we feel alive and very well on our “living island”.

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