YOKOTA AIR BASE, Japan — The volcanic alert level for Mount Asama, about 65 miles northwest of Yokota Air Base in western Tokyo, was raised Thursday by the Japan Meteorological Agency.
Mount Asama, an 8,425-foot peak, is among Japan’s most active volcanoes.
The alert was raised to Level 2, which advises against approaching the volcano’s crater. Level 3 warns against approaching the entire volcano, and Level 4 asks people to prepare for evacuation. The highest threat level — 5 — signals an evacuation.
Mount Asama last erupted in early February 2009, killing a number of hikers and covering Yokota’s streets, buildings and vehicles with a film of volcanic ash.