Thousands to be evacuated as Indonesian volcano threatens to erupt

[Gert van der Hoek]

Re: Thousands to be evacuated as Indonesian volcano threatens to erupt

Mt. Kelud lava dome grows, slows eruption

Indra Harsaputra, The Jakarta Post, Kediri

The Mount Kelud observation team reported Tuesday that the slab of cold lava in the middle of the mountain's crater has grown.

"Its getting taller, now it is about 70 meters tall. Its diameter has also increased to over 100 meters," observation team member Agus Budiarto said, adding that the crater itself was only 200 meters in diameter.

The island-like structure of cold lava was first spotted on Monday by the observation team's visual monitoring equipment. The team believed the cold lava was blocking the exit route of the lava, thus preventing Mount Kelud from erupting.

Agus, who referred to the slab as a "lava dome", said the observation team believed the dome was made of andesit stone.

"This lava dome will keep getting higher and bigger. Frankly speaking, we don't know whether it will form a small mountain itself. We also don't know whether Mount Kelud will explode or if all its volcanic activities will stop after it gives birth to this lava dome," he said.

So far, the upward thrusting movement of the lava dome has pushed all water out of the crater.

"The lava dome caused that event. We estimated the crater housed over 2.5 millions cubic meters of water. We don't know how much water was pushed out by the lava dome, neither do we know whether the water was dangerous to human beings," Agus added.

Agus said lava domes were not uncommon and usually occurred following a volcanic eruption. Similar domes formed after the eruptions of Mount Awu and Mount Soputan. The team believes Kelud's dome is from the 1990 eruption.

"The formation of the dome pushed the temperature inside the crater up. Now, its about 100 degrees Celsius down there," Agus said.

As of Tuesday, a tall column of thick sulfuric smoke was still billowing out of the crater. The team said the smoke was believed to be one kilometer high.

They also said the public needed to remember that the smoke was extremely poisonous and that the peak was still off limits.

However, Erfan, a photographer for a local newspaper who entered the restricted zone, said that many villagers were still in the area near the crater.

"Despite the warnings, we met no difficulties in entering the zone. The entry point wasn't even guarded by the police as it is supposed to be," he said.

http://www.thejakartapost.com/detailheadlines.asp?fileid=20071107.@02&irec=1

 

[Niko]

Re: Thousands to be evacuated as Indonesian volcano threatens to erupt

Experts on edge as Indonesia's volcanoes rumble to life

Wed Nov 7, 2007 11:08am GMT
By Ahmad Pathoni

JAKARTA (Reuters) - Indonesia's top volcano watcher, Surono, has had a frantic time in the past month. No fewer than four volcanoes on his watch have suddenly rumbled to life, giving the 52-year-old geophysicist and his staff many sleepless nights.

The head of Indonesia's Centre for Vulcanology and Geological Hazard Mitigation and his colleagues are keeping a close eye on the famous Anak Krakatau, or "Child of Krakatau", and on Java's Mount Kelud, which is particularly hard to monitor because of its crater lake.

Last week, Surono, who obtained his doctorate from France's Universite de Savoie and speaks French, decided to move his office temporarily from the peaceful hill-top city of Bandung in West Java to a monitoring post near Mount Kelud.

While Surono kept a close watch on Kelud, whose crater lake has turned from blue to white because of all the sulphur bubbling up from inside the volcano, some of his colleagues have been dispatched to the Sunda strait separating Java and Sumatra to monitor Anak Krakatau.

The island volcano is a popular tourist attraction, but now tourists have been told to stay away as Child of Krakatau is spewing ash. The volcano was gradually formed after its famous "parent" Krakatau blew up in a massive eruption in 1883, triggering tsunamis and killing thousands of people.

Alerts have also been issued for Mount Soputan, in North Sulawesi, which erupted last month spewing columns of ash 1,000 metres high, and Mount Karangetan off Sulawesi island.

"I have had many sleepless nights. But I have no complaints. This is my life choice and I have to take the risk," said Surono, who admits he has taken to catnapping in his car to catch up on lost sleep.


HIGH ENERGY
Indonesia has the highest number of active volcanoes of any country, sitting on a belt of intense seismic activity known as the "Pacific Ring of Fire".

Kelud lies about 90 km southwest of Surabaya, the capital of East Java province and Indonesia's second-largest city. An estimated 350,000 people live within 10 km (6 miles) of the 1,731-metre (5,700-foot) volcano, farming on the rich volcanic soil in the area.

Surono's office raised Kelud's alert status to the highest level on October 16, as its activity increased and an eruption appeared imminent. The authorities tried to persuade nearby villagers to evacuate the area, but with mixed success.

The volcano's name means "sweeper" in Javanese, a reference to the fact that when it erupts, it sweeps away everything in its path. About 5,000 people died in 1919 when it spewed scalding water from its crater lake.
At the Kelud monitoring post, Surono oversees a team of 22 scientists including geophysicists, and computer and seismic experts. It is the biggest team devoted to monitoring a volcano in the country.

On Saturday, the volcano experts initially thought that Kelud, which was obscured by cloud, had erupted. The lake's temperature had surged and the frequency of tremors went off the scale of the monitoring equipment and could no longer be read by instruments.

But a few hours later, the scientists changed their minds and they are still waiting for the volcano to blow.

"The complexity of Kelud is very high. Its character is hard to comprehend," Surono said.


SUPERSTITIOUS
Since Kelud's activity increased last month, the volcano has released energy four times as strong as when it erupted in 1990, when about 30 people were killed, Surono said.

But so far, the energy has only sent boiling water spilling from the crater lake down one side, he said.

As the number of tremors soared and the temperature of the crater lake suddenly jumped on Saturday, Surono ordered his team to evacuate the post, fearing for their safety.

"They are valuable assets and they must survive to protect the safety of the people," said Surono. But he is concerned that many residents living nearby underestimate the danger.

Many villagers in Java are superstitious, and in this particular area they believe that as long as they turn off the lights and do not speak ill or loudly, the spirit of the volcano will calm down.

Some also say that they know the character of the mountain well and can take care of themselves in the event of an eruption.

"(But) people don't understand that an upcoming eruption may be entirely different from the previous ones," Surono said.

http://uk.reuters.com/article/reutersEdge/idUKNOA73978120071107?pageNumber=3

 

[Gert van der Hoek]

Re: Thousands to be evacuated as Indonesian volcano threatens to erupt

Indonesian volcano calms, alert status lowered

MOUNT KELUD, East Java (AP): Indonesia lowered the alert status of the Mount Kelud volcano on Thursday, meaning that thousands of people who have fled its slopes for government shelters may return home.

Kelud on the densely populated island of Java has been on top alert for several weeks.

"The volcano no longer has the energy needed for an explosive eruption that would threaten the lives of people living nearby," chief volcanologist Surono said in explaining the decision to downgrade Kelud's status.

In 1990, Mount Kelud spewed searing fumes and lava that killed more than 30 people and injured hundreds. In 1919, a powerful explosion that reportedly could be heard hundreds of kilometers away killed at least 5,160.

Thousands of people from villagers close to Kelud's crater lake have heeded evacuation orders and been staying at tent camps or government buildings, but many have ignored the warnings and remained in the danger zone.

The government volcano agency said Kelud remained on the second highest alert level and told villagers to remain alert because the mountain was very unpredictable. It said that villagers could return home, but not to venture close to the crater which was still emitting smoke. (**)

http://www.thejakartapost.com/detailgeneral.asp?fileid=20071108130556&irec=0

 

[Gert van der Hoek]

Re: Thousands to be evacuated as Indonesian volcano threatens to erupt

Mt. Kelud lava dome seen as warning sign

Indra Harsaputra, The Jakarta Post, Surabaya

Geologists from 10th November Institute of Technology (ITS) in Surabaya on Thursday say the lava dome that has formed on Mount Kelud's lake crater is not a new phenomenon, and could indicate an eruption is imminent.

They said a similar lava dome was reported before the 1919 eruption that claimed more than 5,000 lives.

They also warned the lava dome could amplify the intensity of an eruption and the damage to surrounding areas.

Geologist and head of the School for Disaster Studies at ITS, Amien Widodo, said documents from the Dutch colonial administration described the formation of a lava dome on Kelud.

"The said the lava dome, comprised of andesite lava, disintegrated and was thrown up during the eruption in the form of large rocks and pebbles, followed by a sand shower," he told The Jakarta Post on Thursday.

He added that the depth of the lake crater increased due to the magmatic pressure from the lava pocket. However, the documents did not specify the depth of the lake in detail.

The current depth of the lake crater is 38 meters, holding about 2.5 million cubic meters of water.

"The eruption in 1919 is recorded as the most fatal in the volcano's history, taking a toll of 5,160 lives," said Amien.

He said the presence of the lava dome, along with tremors and discharges of ash up to 120 meters high, must be taken as a serious warning sign.

"In theory Mount Kelud is ready to erupt. The higher the dome grows, the greater the possibility of an eruption," said Amien.

He said it was difficult to gauge the mountain's current Volcanic Explosive Index (VEI), but data from previous eruptions showed Kelud's VEI ranged from three to five.

A magnitude five VEI eruption took place in 1856. The force of that explosion was similar to explosions by the Philippines' Mount Pinatubo in 1991 and Mount St. Helens in the U.S. in 1980.

By comparison, the legendary eruption of Mount Krakatau in 1883 was a magnitude six VEI. The eruption killed more than 36,000 people.

"It's difficult to predict when Mount Kelud will erupt, but a number of theories imply that a full moon could have an influence on volcanic activity," said Amien.

Head of the Volcanology and Geological Disaster Mitigation Center's Volcano Observation Division, Agus Budianto, said there was every possibility Mount Kelud would erupt.

The lava dome is expanding daily and now covers 90 percent of the lake crater, reaching 300 meters in diameter and a height of 120 meters.

"We will constantly monitor Mount Kelud," Amien told the Post.

Sugihwaras village administrative chief in Ngancar district, Kediri regency, Susiadi, said residents were still going about their daily activities, but there had been growing concerning since Kelud was placed on top alert status on Oct. 16.

"Residents have held a traditional jaranan ritual to appease the mountain. They were told that Mount Kelud would erupt before the end of the year," said Susiadi.

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