Tuesday, November 06, 2007

Active Earth: Indonesia Volcano Nears Eruption

Reports say Indonesia Volcano Nears Eruption:
Indonesia's Mount Kelud volcano has moved closer to an eruption scientists say, as a magma dome began forming under its crater lake causing boiling water to spill down its sides.

Soaring temperatures in the lake has also damaged monitoring equipment used to gauge activity on the mountain that has been on the verge of an eruption for weeks.

Saut Simatupang, an official at Indonesia's Centre for Volcanology and Geological and Hazard Mitigation, told Reuters: "Increased underground magma movement has built up pressure on the blocked entrance, causing the bottom of the lake to rise and crack."

Efforts to estimate the size of the dome, already visible in the crater lake, were hampered by thick clouds of steam.

The area around Mount Kelud, among the deadliest of Indonesia's 100 active volcanoes, has been on the highest level of alert for more than two weeks.

Surono, one of 16 volcanologists monitoring activity at Mount Kelud around the clock, said the temperature in the lake was so great that their equipment nearby had stopped working.

Some 350,000 people live in the area around Mount Kelud and several thousand have been moved to government shelters.

However, tens of thousands more have ignored evacuation warnings, choosing to stay behind to tend their crops and livestock.

Hundreds fled their villages as Mount Kelud
entered a critical phase [EPA]
In 1919, Mount Kelud spewed scalding water from its crater lake, killing about 5,000 people.

Scientists predict that Mount Kelud's eruption could be bigger than the one in 1990 which killed at least 30 people.
A more recent report indicates an "island" has formed in the middle of the crater's lake:
An island that has emerged in the middle of the crater lake of Indonesia's Mount Kelut may have been effectively plugging the volcano but it could be dislodged, scientists warned Tuesday.

The peak in East Java, whose fertile slopes are populated by thousands of people, was put on high alert on October 16 but has not fully erupted, puzzling scientists who say it is impossible to predict what may happen next.

"The island was visually captured by our CCTV (closed-circuit television) on Sunday, with smoke now pluming up to one kilometre (half a mile) from it," volcanologist Saut Simatupang told AFP.

He estimated that the 100-metre (-yard) long island loomed 20 metres above the surface of the crater lake. The temperature of the lake has soared so high it has broken measuring instruments, he said.

"We still cannot determine whether (the island) is new product or old lava from the 1990 eruption that had solidified at the bottom of the crater lake," more or less acting as a cork, he said.

It appeared to have been pushed up Saturday night, when volcanologists mistakenly thought an eruption was occurring so they abandoned their posts.

Overnight, continuous tremors shuddered underneath Kelut, with dozens of puffs of steam or smoke shooting into the air, Simatupang said.

"We are not taking a chance yet to get closer to study the volcano, although we think it is mostly steam coming out," said Simatupang.

"This could go on or it could be that the volcano is keeping its energy for a bigger eruption."

The head of Indonesia's Volcanology and Geological Disaster Mitigation Agency, Surono, told President Susilo Bambang Yudhoyono that Kelut appeared to have altered its normal eruptive behaviour.

"There seems to be a change in the volcano's character, from historical explosive eruptions to an effusive or slow eruption," he said during a phone call broadcast on ElShinta radio.

"Is it possible that there will be an eruption (given the change), or can we still not have an accurate prediction?" Yudhoyono asked.

"There is a very small probability that there will be an explosive eruption, but I am still doing more evaluation with my colleagues," Surono replied.

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