Mount Ruang Erupts in Indonesia, Spewing Lava Thousands of Feet Into the Sky

Mount Ruang, a volcano in Indonesia, erupted on Tuesday, spewing fiery lava and ash thousands of feet into the night sky and forcing the evacuation of hundreds of people in the North Sulawesi province, according to the authorities and local news reports.

The volcano erupted at about 7:19 p.m. local time, Antara, the national news agency, reported. The country’s National Disaster Mitigation Agency said on Wednesday that more than 800 people in nearby villages were displaced by the eruption, many using ferries and taking shelter in churches and community centers.

The authorities said supplies such as mats, blankets, cleaning materials, and tents were needed, and that more shelters might be opening for people fleeing the volcano.

Indonesia is the world’s largest archipelago nation. It is spread across what is known as the Ring of Fire, where tectonic plates clash under the surface of the Pacific Ocean and spawn earthquakes and eruptions from volcanoes.

Mount Ruang is a stratovolcano, or a steep, conical volcano that has built up over years in layers from explosive eruptions of lava, rock fragments, ash and other properties.

“It is in a part of the world where there are a lot of active volcanoes,” said Dr. Tracy K.P. Gregg, who chairs the Department of Geology at the University at Buffalo.

Its last major eruption was in 2002, when the column of lava and ash that it spewed reached up to 17 miles, Dr. Gregg said.

She said the volcano in 2002 measured 4 on the Volcanic Explosivity Index, a scale used to measure the strength of an eruption by looking at several factors, such as duration, ash volume and plume height. Mount Pinatubo in the Philippines in 1991 measured 6 on the index. Mount St. Helens in the United States in 1980