Thu, 14 Apr 2005

Increased activity spotted in two more volcanoes

The Jakarta Post, Bandung/Padang/Jakarta

Two volcanoes in the western part of the island of Java have registered increased activity on Wednesday, only a day after the Mt. Talang volcano erupted in West Sumatra, sparking fear that more terrifying natural disasters would soon rock the country.

A government official imposed an alert status for Mt. Anak Krakatau in the Sunda Strait on Wednesday morning after 32 mild earthquakes rattled the volcano's crater. An alert status is issued whenever a series of earthquakes in the area of a volcano occurs, followed by an increase in temperature.

"Over the past two weeks, mild earthquakes have occurred two to nine times a day, but suddenly today 32 earthquakes were registered," said Surono, a volcanology and geological disaster mitigation official.

Similarly, increased activity was also found in the Mt. Tangkuban Perahu volcano near Bandung, some hundreds of kilometers east of Mt. Anak Krakatau. While on normal days earthquakes from the volcano happened between two and seven times a day, on Wednesday 100 earthquakes were recorded, according to Surono.

On Wednesday, Government officials asked 150 local and foreign tourists to stay away from the crater of Mt. Tangkuban Perahu.

Kuswardi, the chief of a volcano observation post, said that the areas around the volcano had been closed to the public since 8 a.m. on Wednesday. "We are afraid that the volcano will erupt suddenly," said Syamsul Rizal, a senior official with the directorate. In the meantime, residents had to watch out for possible emissions of poisonous gases from the volcano's crater, Syamsul added.

The volcano, a smoldering 2,076-meter high mountain located near densely populated Bandung city, last erupted two years ago. The other volcano, Anak Krakatau, last erupted four years ago, spewing hot ash and black smoke.

Syamsul has speculated that the Mt. Talang eruption and the increased activity on Mt. Tangkuban Perahu and Anak Krakatau were closely related to the series of huge earthquakes that rocked Aceh and Nias island recently.

The first earthquake that hit Aceh province on Dec. 26 last year registered 9.3 on the Richter scale, while another quake on March 28 that jolted the island of Nias registered 8.7.

"The two huge earthquakes have created a domino effect. They have stirred instability on the west Sumatra plate," said Syamsul. The earthquake happened after the Indo-Australia plate pushed the Euro-Asia plate in the western part of Sumatra, making the area unstable. The movement, that unleashed hot energy, has melted rocks inside the earth and turned it fluid, pushing magma to the surface, according to Syamsul.

Meanwhile, volcanic activity has decreased at Mt. Talang in Solok regency, West Sumatra, a day after it erupted on Tuesday.

Dalipa, a volcano observer, said that between Tuesday evening until Wednesday afternoon, no significant eruptions have occurred at the volcano.

The situation was quite different to early Tuesday morning, when a large eruption spewed ashes up to a kilometer high. Ash fell as far as 10 kilometers away, and reduced visibility to five kilometers. The eruption was believed to have been triggered by a 6.7 tremor that jolted the island of Siberut in West Sumatra on Sunday.

Separately, governors from across the archipelago attended a lecture on earthquakes at the State Palace. Wednesday evening's lecture was held at the invitation of President Susilo Bambang Yudhoyono, and is aimed at providing knowledge for governors on earthquakes and volcanic eruptions so that they can be better prepared if such disasters strike their areas.