photo by EfrankE

Sunday, May 23, 2010

10,000 Days Below the Volcano

This last week we passed the 10,000th consecutive day of volcanic activity on the Big Island. Eruption activity began January 3, 1983.

Here’s a time-elapsed clip of minor activity occurring at Halemaumau crater on a day the trade winds were blowing.
Video clip used with permission by EfrankE

Most of the flowing lava comes out of the side of Mauna Loa. The volcano has overlaid old lava with new, destroyed homes and forest land, closed a main road with lava and even extended the cliffs of the island a little farther out into the sea, but mostly it has produced a lot of steam and gas emissions. Note: The banner photo at the top of this page is a shot of Hualalai Mountain, a dormant volcano which separates us from the actively volcanic south-eastern part of the island.

The output of sulfur dioxide varies from 200 tons to 2,000 tons per day. It acidifies the rain, at times, to the detriment of Big Island crops. When molten lava flows into the ocean the sulfur dioxide combines with the seawater to form steam clouds of hydrochloric acid. It’s good to avoid the area on those days.

It’s always more pleasant in Kona when the trade winds are blowing, sending the vog (volcanic version of smog) southward and out into the Pacific. In the summer, Kona winds prevail much of the time and bring the vog northward along the leeward coast, spoiling otherwise pleasant views.

The long-term health effects of breathing air with a high concentration of sulfur dioxide for 27 years are still unknown, though not expected to be beneficial.

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