Indonesia’s Mount Merapi appeared calm again on Thursday as hundreds of evacuees drifted back home, unconvinced they were in danger from the simmering volcano.
But scientists warned that despite an apparent slowdown in the growth of a magma-filled dome at its peak — which may collapse and eject millions of cubic metres of volcanic rock and lava — the volcano remained temperamental.
”There is still the potential for danger,” Subrandriyo, the head of the Merapi monitoring section at the volcanology office in Yogyakarta, 30km south of the volcano, told reporters.
Asked whether the new dome bulging at its peak was now slowing its expansion, he said: ”At present, today, it looks that way. The growth now is not as fast as in the initial period … We still need several days to observe how the dome is growing.”
He said the prospect of a deadly disaster at Merapi, which has repeatedly unleashed its fury and killed in the past, depended on the volume of gas inside the dome. If it was high, the possibility of a dome collapse was greater.
Subrandriyo also warned that if the new dome keeps growing it may pull down older domes underneath it when it collapses.
”If the total collapses, it would be around seven million cubic metres [of material falling] and our estimate is that it would reach over 8km” down the slope, he said.
Authorities last Saturday declared Merapi in danger of imminent eruption, triggering the evacuation of thousands of people to makeshift shelters around its base.
The main fear is that the dome, which is leaning southward, may implode and shoot out blazing lava as well as heat clouds, as has historically occurred at the volcano rising from the fertile Kedu plain in Central Java.
The volcanology office recorded eight potentially deadly heat clouds, known locally as ”shaggy goats”, speeding down the volcano’s slopes between midnight and 6am local time on Wednesday.
They extended for a maximum 1,5km and caused no harm.
Seven heat clouds, flowing as far as 2,5km down the slopes, were monitored later in the day.
During the first six hours on Thursday, 44 lava falls were registered, compared with 180 for all-day on Wednesday when smoke also soared 400m from the 2 914m), volcano whose name means ”Mountain of Fire”.
In one settlement in the declared danger zone, life appeared back to normal on Thursday, with men, women and children trudging higher up the volcano’s slopes to harvest chillies and tend to their corn and rice crops.
”For us, it is normal. We are used to this. Every year there must be some ash blowing this way,” said one of the villagers, Sarianti.
The hamlet was on Wednesday covered in a thin layer of ash blown across from the heat clouds.
In Magelang district, the head of the health agency, Hendarto, urged residents to wear face masks when venturing outside to avoid inhaling ash. He said officials were preparing to distribute some 23 000 free masks to the public, according to Antara news agency.
Official data showed that nearly 1 400 people had left temporary shelters to return home and fend for themselves, leaving more than 20 700 others either in shelters or receiving aid and being tracked by authorities.
The elderly customary guardian of Mount Merapi, Marijan, was due on Thursday evening to hold a traditional ceremony at his home near the volcano’s peak to ask ancient Javanese spirits for protection and safety.
Marijan, appointed by the ninth and late Sultan of Yogyakarta, has so far refused to leave his home and has trudged higher up the volcano to meditate, saying he has not seen any traditional omens suggesting an imminent eruption. — AFP
