Kelud eruption could be massive

Indra Harsaputra, The Jakarta Post, Kediri

Cooled lava from a 1990 eruption has blocked magma at Mount Kelud in East Java, which authorities warn could cause a larger eruption this time around.

Head of observation at the Bandung-based Volcanology and Geological Disaster Mitigation Center, Mohammad Hendrasto, said Tuesday it was this threat of a larger eruption that prompted the authorities to leave the volcano on top alert.

He said an increase in the temperature of Kelud's crater lake also contributed to the decision not to lower the volcano's alert status.

He said the volcano, which has been on top alert status since Oct. 16, has continued to experience two to three volcanic quakes a day.

"These indicators have shown there is still a lot of activity at Kelud. The threat of eruption is still imminent, although we can't be sure when the explosion will take place," he said at a press conference.

On Tuesday afternoon, the temperature of the crater lake was 35.6 degrees Celsius on the surface, 38.2 degrees Celsius at a depth of 10 meters and 39.5 degrees Celsius at a depth of 15 meters.

He said authorities believed the volcano erupted on Oct. 16, when 510 volcanic quakes occurred in a single day.

During the 1990 eruption, the volcano recorded 327 quakes.

From Oct. 16 to Tuesday, the magma has reached a depth of 700 meters, he said.

"After further observation over the past four days, we found cooled that has blocked the magma's passage out.

"We don't precisely know how thick the cooled lava is, but when the volcano does erupt it will send out more solid materials than in previous eruptions," Hendrasto said.

A member of the disaster center's team monitoring Kelud estimated the cooled lava was more than 4.3 kilometers thick and that if the volcano erupted, it might spew out solid materials for up to three hours.

"If this scenario happens, this year's explosion will be much worse than previous eruptions on record. It might even be bigger in terms of other volcano eruptions in the country," he said.

The cooled lava could be expelled as large stones that could be thrown very long distances, considering the amount of pressure built up inside the volcano.

He recommended residents living within a 10-km radius of the crater remain in shelters.

He warned that the longer the magma was blocked inside the volcano, the more carbon dioxide would accumulate. The gas has started coming out from cracks near the crater, but authorities do not have the equipment to measure the levels of the gas.

Many residents, however, have ignored the warnings and returned to their homes.

Returning residents say they have survived past eruptions and are not worried about Kelud's current rumblings.

"The residents no longer believe the government. I'm tired trying to persuade them to evacuate.

"I have distributed disclaimers to ensure the residents will not sue if they're injured in the eruption," Sugihwaras village head Susiadi told The Jakarta Post.

Disclaimers have been distributed to 790 families in Ngancar district in Kediri regency.

"I don't want to be blamed by people if there is an eruption," he said.