Eruption pause provides an opportunity to probe volcanic pollution

Only small amounts of sulfur dioxide (SO2) and hydrogen sulfide (H2S) are currently being released from Kilauea, but they chemically react with each other (oxidation-reduction reaction) to form the bright yellow sulfur deposits visible on the crater walls within Halemaumau. The current low sulfur emission rates at Kilauea have contributed to beautifully clear skies in downwind areas. (USGS photo by M. Poland)
This photo compilation shows Sheraton Kona Resort and Spa at Keauhou Bay from the scenic lookout on Kamehameha III Road amid heavy vog on May 29 (top) and in September amid better air quality. (Laura Ruminski/West Hawaii Today)

HAWAII VOLCANOES NATIONAL PARK — The end of Kilauea’s 2018 eruption this past September was accompanied by an enormous decrease in the amount of sulfur dioxide gas (SO2) emitted from the volcano. This has led to beautifully clear skies gracing Hawaii Island, particularly noticeable on the west side, where the volcanic pollution known as vog chronically collected in past years.