Mount Aso, about 1,000 kilometers (625 miles) southwest of Tokyo on Kyushu island, is one of the world’s largest active volcano. Earthquakes and other seismic activity stepped up in late August. Mount Aso has one of the largest calderas in the world (25 km north-south and 18 km east-west). The caldera has a circumference of around 120 km.
A volcano in southern Japan blasted out chunks of magma in the first such eruption in 22 years, causing flight cancellations and prompting warnings to stay away from its crater.
The ash reached an elevation of one kilometer (3,280 feet) and could cause continuing air delays, according to the Japan Meteorological Agency.