Vog
Vog is a form of air pollution that results when sulfur dioxide and other gases and particles emitted by an erupting volcano react with oxygen and moisture in the presence of sunlight. The word is a portmanteau of the words "volcanic", "smog", and "fog". The term is in common use in the Hawaiian islands, where the Kīlauea volcano, on the Island of Hawaiʻi (aka "The Big Island"), has been erupting continuously since January 3, 1983. Based on June 2008 measurements, Kīlauea emits 2,000–4,000 tons of sulfur dioxide (SO2) every day.
Vog is created when volcanic gases (primarily oxides of sulfur) react with sunlight, oxygen and moisture. The result includes sulfuric acid and other sulfates. Vog is made up of a mixture of gases and aerosols which makes it hard to study and potentially more dangerous than either on their own.
In Hawaii, the gas plumes of Kīlauea rise up from three locations: Halemaʻumaʻu Crater, Puʻu ʻŌʻō vent, and from along the coastline where lava flows from the East Rift zone enter the ocean. The plumes create a blanket of vog that can envelop the island. Vog mostly affects the Kona coast on the west side of the Island of Hawaiʻi, where the prevailing trade winds blow the vog to the southwest and southern winds then blow it north up the Kohala coast.
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