Mount Sinabung in Karo regency, North Sumatra, erupted again early Friday, with volcanologists calling this latest eruption stronger than two previous eruptions, prompting residents to return to shelters.
The Volcanology and Geological Disaster Mitigation Center (PVMBG) said the third eruption began at 4:38 a.m. and lasted 13 minutes.
PVMBG head Surono said the eruption was very powerful and its tremors could be felt as far away as 8 kilometers, stronger than previous eruptions.
“This was the strongest eruption as ash plumes reached 3,000 meters,” Surono told The Jakarta Post on Friday.
Since Sunday, the 2,460-meter tall Mt. Sinabung — which lay dormant for more than four centuries — has erupted three times, with the first eruption in the early hours of Sunday, discharging volcanic ash as high as 1,500 meters. It erupted again the next day, spewing ash up to 2,000 meters high.
PVMBG Volcano Observation subdivision head Agus Budianto said that Mt. Sinabung had shown an daily increase in volcanic activity, meaning it was still active and further caution had to be taken.
He said he could not confirm whether a much larger eruption was possible.
“We are still monitoring all variables. If we see indications that an eruption is imminent, we will inform people so they can get to safety,” said Agus, who also leads the Mt. Sinabung Disaster Response team.
He said that when Mt. Sinabung was about to erupt on Friday morning, the volcanology team had informed the local administration of the possibility of the eruption, allowing residents living within a 6-kilometer radius of the volcano to quickly evacuate.
“We informed the administration about the imminent eruption on Thursday after monitoring a rise in tremors,” Agus said.
Karo regency administration secretary Makmur Ginting confirmed the information from the volcanology team.
Equipped with the information, he said, the administration again evacuated residents, who had started returning to their homes.
Makmur said 15 trucks were deployed to transport residents back to the shelters.
“The evacuation process ran from 12 midnight to 3 a.m. An hour later, we observed a very intense volcanic eruption,” he said, adding that volcanic ash darkened the skies and coated everything.
Makmur said the number of evacuees had risen to 24,000 following Friday’s eruption, from 4,000 on Thursday.
The third eruption caused severe panic among residents, who had returned home earlier from shelters.
Anto Tarigan, a farmer in Tiga Pancur village in Simpang Empat district, said he watched the eruption from his home 5 kilometers away.
The eruption, he said, terrified people due to its loud rumble.
“We did not see lava flow, but thick smoke billowed up to the sky followed by thunderous sounds,” Anto said, adding that he immediately fled to safety with his family.
Anto said he and his family had evacuated twice. They returned home two days ago to inspect their farm and livestock because there were no signs of an imminent eruption.