Explosions intensified on Hawaii's Kilauea volcano on Tuesday, spewing ash and sparking a red alert for aviation for the first time since the latest eruption began 12 days ago.
Ash and volcanic smog, also known as vog, rose up to 12,000 feet (3,657 meters) above Kilauea's crater and floated southwest, covering cars on Highway 11 with gray dust and sparking an "unhealthy air" advisory in the community of Pahala, 18 miles (29 km) from the summit.
An aviation red alert means a volcanic eruption is underway that could affect aviation by spewing ash into air routes, according to the U.S. Geological Survey (USGS) website.