What to know about the eruptions of Mount Lewotobi Laki Laki that killed 9 in Indonesia

A series of volcanic eruptions of Mount Lewotobi Laki Laki on Indonesia’s remote island of Flores killed nine people and injured dozens of others, as buildings crumbled and terrified residents ran for their lives in the darkness.

The eruptions on Monday affected more than 10,000 people in 10 villages. About 4,400 villagers moved into makeshift emergency shelters after the eruption, which destroyed seven schools, nearly two dozen houses and a convent on the majority-Catholic Island.

Authorities on Wednesday provided tons of logistical and aid supplies to displaced people and warned the thousands of people who fled not to return home, as rescue workers, police and soldiers continued to comb the devastated villages for survivors despite no missing people reported.

Here’s a closer look at the eruption and its aftermath.

How many active volcanoes are there in Indonesia?

The 1,584-meter (5,197-foot) Mount Lewotobi Laki Laki is one of 120 active volcanoes in the country. Indonesia is prone to earthquakes, landslides and volcanic activity because it sits along the “Ring of Fire,” a horseshoe-shaped series of seismic fault lines around the Pacific Ocean.

Indonesia’s Center for Volcanology and Geological Disaster Mitigation has recorded 4,796 volcanic eruptions across the vast archipelago nation since January. Mount Ibu in North Maluku province has erupted 1,930 times, Mount Semeru in East Java province 1,634 times and Mount Lewotobi Laki Laki 872 times.

About 6,500 people were evacuated in January after Mount Lewotobi Laki Laki began erupting, spewing thick clouds and forcing the government to close the island’s Frans Seda Airport. No casualties or major damage were reported, but the airport has remained closed since then due to seismic activity.

Why was the latest volcanic eruption so powerful?

Since January, Mount Lewotobi Laki Laki had erupted up to six times almost every day, but its activity drastically fell in early November, said Muhammad Wafid, who heads the geology agency at the Energy and Mineral Resources Ministry.

Analysis showed there was a blockage of magma in the crater, which reduced detectible seismic activity and increased pressure, Wafid said.

“The eruptions that occurred since Friday were due to the accumulation of hidden energy,” Wafid said, adding that the agency has recommended the volcano’s alert status be raised to the highest level.

“Currently there is no technology capable of determining when a volcanic eruption will occur and how big the eruption will be,” he said, “What we do is monitor the signs that there will be an eruption, but we don’t know when it will be.”

How common are deadly eruptions in Indonesia?

Many eruptions in Indonesia are minor and cause little to no damage, but some can be deadly.

Mount Marapi erupted in December 2023, killing 24 climbers and injuring others who were caught by its sudden weekend eruption. Two climbing routes in the mountain have been closed since then. Five months later, monsoon rains triggered a landslide of mud and cold lava from Mount Marapi, causing rivers to breach their banks. The deluge tore through mountainside villages and swept away people and dozens of homes, killing 67 people.

An eruption in December 2021 of Mount Semeru, the highest volcano on the densely populated Java island, left 48 people dead and 36 missing in villages that were buried in layers of mud. Mount Merapi also erupted in 2010, killing 347 people and displacing 20,000 villagers.

The monumental eruption of the Krakatau volcano in 1883 triggered a period of global cooling.