Mount Merapi spewed lava along and sent hot ash clouds down its slopes Friday, easing pressure inside the volcano and making another big eruption less likely.
Volcanology and Geological Disaster Mitigation Center (PVMBG) chief Surono said Friday that volcanic activity should decrease following the release of lava.
However, the volcano’s status remains on high alert and the area remains restricted, he told news portal kompas.com.
Safari Dwiyono, a scientist who has been monitoring Mt. Merapi for 15 years, said the latest volcanic activity appeared to be easing pressure behind a lava dome that had formed in the crater.
“If the energy continues to release little by little as is occurring presently, it reduces the chances of a bigger, more powerful eruption,” he was quoted as saying by The Associated Press.
Mt. Merapi, usually considered a “non-explosive” volcano — characterized by a slow expulsion of lava in 2006 — turned explosive on Tuesday afternoon when it propelled blasts of hot ash 1.5 kilometers into the sky, an unusual display for the volcano.
The Mt. Merapi section head of the Yogyakarta Volcanic Technology Development and Research Center (BPPTK), Sri Sumarti, said lava started to spew Thursday night, two days after its first eruption on Tuesday, which has killed 33 people.
“The explosive eruption has as well opened a way for the pressuring magma to surface,” she said Friday.
The world’s most active volcano also coughed up hot ash clouds down of its southern slopes, heading to Cangkringan district in Sleman regency, Yogyakarta.
Sri said the first cloud on Friday morning was not huge but was followed by bigger ones, reaching down some 3 kilometers and lasting four to nine minutes, raining ash that reached as far as the Central Java town of Magelang.
The ash clouds panicked residents who were seeking grass to feed their cows, forcing them to flee to the nearest evacuation centers.
Military and the police officers on duty at the quake-prone areas in Kaliadem and Kinahrejo villages were also seen running from their posts to safety.
Authorities beat drums loudly and repeatedly, reminding people to run to safety.
“I was cutting grass when I heard the sounds and saw the ash clouds. I ran for my life,” said Legimin, a resident of Pangukrejo village.
At the shelters, some residents were crying, worried for relatives who had returned to their houses to take care of their livestock. “My husband is looking for grass and has not come back,” said Darsih, holding her child.
Most of the evacuees usually return home in the morning to take care of their livestock and go back to the shelters in the evening.
Separately, Andi Suardi, the head of the Mt. Krakatau observatory in South Lampung regency, said Friday that Krakatau’s activity had increased in the past four days and its status had been raised from normal to the second level.
He said 136 eruptions were recorded on Friday. “We normally only record 10 eruptions a day at most,” he told Antara news agency.