Jakarta. Experts agree the Mount Kelud eruption could have far more impact on the country, but only if the recent intense eruption is repeated.
“Much depends on the intensity of any future eruptions,” Mulyono Prabowo, a spokesman for Jakarta’s Meteorology, Climatology and Geophysics Agency (BMKG), said on Friday.
Mulyono said the BMKG had received reports that the ash had reached parts of West Java, including Bandung, some 600 kilometers from Kelud in East Java, but he was sure that if there were no further explosive eruptions the ash cloud would not travel much further.
“The eruption of Kelud was quite big, with the ash reaching as high as 17 kilometers, and that’s what caused the wide spread of the ash all the way to Bandung,” Mulyono said.
“The wind plays a major role in spreading the ash and dust. High up in the stratosphere the wind averages around 16 to 17 kilometers per hour,” he said.
On the other hand, at lower altitudes, 1,000 meters or lower, the wind speed is not as fast, perhaps reaching about 10 kilometers per hour.
“That may explain why the ash cloud has not traveled so far in an easterly direction,” Mulyono said.
The short- and long-term effects of the eruption will depend on how long Kelud keeps on erupting and how powerful the eruptions are.
Mulyono said the most visible impact of the eruption would be on human health.
A high level of exposure to the ash and dust could result in widespread chronic respiratory and lung diseases, asthma, allergic and eye irritations.
“Another impact that could affect many people, as we have already seen, is on the closure of airports in areas close to the volcano,” he said.
“Temperature changes could also occur in the areas that have been impacted by Kelud activities.
“It will reduce solar radiation, which leads to lower air temperatures and a colder temperature on the ground. However, we cannot predict how big and how long the temperature changes will be in the impacted areas,” Mulyono said.
He expressed confidence there would be no impact beyond Indonesia’s borders, given the reduced activity that has followed the initial eruption late on Thursday night.
That said, the volcano still needs to be monitored closely, Mulyono said.
Up until now, the mountain is continuing to spout volcanic ash up to 700 meters into the atmosphere, according to the head of the Volcanology and Disaster Mitigation Center (PVMBG), M. Hendrasto.
“For now we are continuing to record earthquake tremors from Mount Kelud,” Hendrasto said.
“The activity is unpredictable but hopefully it will not be as bad as Mount Sinabung in North Sumatra.”
Hendrasto said the eruption of Sinabung was slow and gradual, which made it worse and resulted in longer-term impacts for the people living within the immediate vicinity of the mountain.
“Compared to Mount Sinabung, Kelud has already had one big explosion. Most of the volcanic material has come out, so we are hoping it won’t take too long to subside,” Hendrasto said.
A previous report estimated that more than 100,000 people had fled from their houses to evacuation areas within a radius of 30 kilometers of the mountain.
However, National Disaster Mitigation Agency (BNPB) spokesman Sutopo Purwo Nugroho said that the number of evacuees had gone down significantly in the late afternoon on Friday because many had returned home.
“As of now, there are 76,388 people in the evacuation areas, with the vast majority from Kediri,” Sutopo told the Jakarta Globe on Friday.