The eruption caused a local power failure and blanketed the provincial capital of Ternate with a thick coat of debris.
Officials immediately closed the island’s main airport, located about 20 miles from Gamalama’s crater, when the mountain roared to life at about 11 p.m. local time on December 4.
The volcano has a history of eruptions going back to at least the early 1700s, when Ternate was home to European forts that supported the spice trade.
An eruption in 1840 destroyed most of the homes on the island. Gamalama's last major eruption was in 2003.