The currently active vent at the Halemaumau Crater is much smaller than the one we'd seen from the air earlier in the day, but it opened with a bang (literally) less than two months before our visit when a large chunk of the crater wall was blown out. The explosion destroyed an observation post along the edge of the crater, and the continuing plume had resulted in the closure of a big stretch of the ring road around the crater and all those warning signs about air quality.




I try to look serious in front of giant gas cloud.




The park rangers had set up spotting scopes so that visitors could see the open vent and the destroyed observation post on the far side of the crater.




I spotted this sign tucked away behind some bushes at the observatory. It did not make me feel any better that it was kept within easy reach rather than locked away indoors.