HILO, Hawai'i — Another small explosion jolted Halema'uma'u crater early this morning, and high sulfur dioxide emissions detected in Hawaiian Ocean View Estates in Ka'u prompted a short-lived warning about air quality today from Hawai'i County Civil Defense. The warning was downgraded at 10 a.m. after the levels of the gas dropped.

Scientists with the U.S. Geological Survey's Hawaiian Volcano Observatory said a blast at the crater shortly before 4 a.m. deposited faintly pink ash across the Halema'uma'u overlook parking lot and along a section of Crater Rim Drive.

Scientists said the ash appeared to be rock dust, and said they found no volcanic glass fragments in the debris.

At 7:45 a.m. today Civil Defense officials advised residents of HOVE above Hawai'i Belt Road that sulfur dioxide levels there "may be high enough to cause severe reactions (for) those in the sensitive in groups as well as those in the general population."

Civil Defense advised residents to leave the area more than 30 miles from Halema'uma'u if possible, and an evacuation center was set up at the Na'alehu Community Center. The county lifted that advisory at 10 a.m. when sulfur dioxide levels dropped.

Measurements of emissions at the crater on Tuesday found the volcano was generating about 970 metric tons of sulfur dioxide from the site per day, or about five times the normal emissions.