Pyroclastic flows
Located on Sumatra, one of Indonesia’s main islands, the highly active volcano has been spewing hot ash over the past few days, with at least 28 hot ash avalanches registered on Monday, June 16, alone, according to government volcanologists. No injuries have been reported thus far.
Expanding lava dome
Authorities have been closely monitoring Mount Sinabung since the beginning of this month, when its status was raised to the highest alert level due to the growing size and unstable condition of its lava dome. More than 1,200 people were told to leave their homes on Monday, taking to almost 4,000 the number of villagers ordered to seek shelter in June. 
Evacuations
Evacuees included villagers living between 3 to 5 kilometers (2 to 3 miles) from the crater on its eastern and southeastern flanks. “We plan to evacuate five to six more villages in the coming days, that’s around 2,500 residents,” local military commander Asep Sukarna told AFP, adding that people have been taken to shelters some 10 kilometers away from the volcano. 
Reawakening
The 2,460-meter (8,070-foot) volcano had been dormant for 400 years until it first erupted in 2010. Following the eruption, the government upgraded the volcano’s status from category “B” to category “A”, meaning it must be monitored constantly. After a three-year lull, the volcano came back to life in 2013, triggering forest fires and sending searing ash and volcanic gas into the air. 
Fatal eruption
Since then, the volcano has erupted intermittently. In February 2014, it spewed lava, hot rocks and ash 2,000 meters into the air, blanketing the surrounding villages and farms with thick gray ash. The massive eruption also killed at least 16 people, including seven university students who were volunteering to help residents affected by the volcanic disaster. 
Seismic upheaval
Mount Sinabung is one of nearly 130 active volcanoes in Indonesia that sit on a collection of major tectonic fault lines, called the Pacific “Ring of Fire.” In 2010, Mount Merapi erupted in the central province of Java, killing more than 350 people and leaving some 150,000 others displaced. The catastrophe is regarded as the deadliest in the country’s recent history. 
Unpredictability
While scientists continuously monitor Mount Merapi, Sinabung and other Indonesian volcanoes, they say predicting the volcanoes’ activities with any accuracy is an almost impossible task. 
