Java's Mount Merapi volcano threat level rises

Nov. 5 (UPI) -- Authorities in Indonesia on Thursday boosted the threat level for the Mount Merapi volcano, which is near a densely populated area on the island of Java.

Government volcano-watchers elevated Merapi's status to level three of the country's four-tier alert system.

"The potential danger is lava erupting out of the volcano, with volcanic material and hot ash clouds spewing as far as 5 kilometers," the Geological Disaster Technology Research and Development Center said Thursday.

The city of Yogyakarta, with a population of 3 million, is situated about 15 miles south of Merapi and about 70,000 people live close to the volcano.

The agency halted mining in rivers within a 6-mile radius of the volcano's peak and asked that tourist activities, including climbing to the top of the volcano, be suspended. Only disaster officials and researchers will be allowed to venture into the restricted area.

Mount Merapi, more than 9,600 feet tall, is one of the active volcanoes in the Pacific Ring of Fire.

Merapi is classified by geologists as a stratovolcano, possessing a cone surrounded by hardened layers of lava and ash. The volcano is more active because it has an unstable lava dome, which can collapse, causing eruptions.

Most recently, Merapi has been in a slow-motion erupting state since 1987, but the volcano has had 68 historic eruptions since 1548.

In June, the volcano sent smoke and ash into the air, but no one was killed.

Government researchers said the volcano might dribble incandescent lava down its slopes in an effusive eruption, or the volcano could experience a more dangerous explosive eruption that would send lava into the air.

In 2010, an explosive eruption killed about 300 people living near the volcanic epicenter and 400,000 people had to flee from their homes.

"If the eruption is an explosive eruption, the strength will not be the same as the 2010 eruption," Hanik Humaida, head of the disaster center said Wednesday, as reported by the Jakarta Post. "But whether it is effusive or explosive, the eruption of Merapi must be anticipated."

Residents reported lenticular cloud formations above the mountain this week, caused by volcanic activity.

Government disaster staff have prepared at least 35 emergency shelters and are prepared to activate an emergency warning system by phone.

Areas in Java that could be affected by the eruption include Cangkringan district in Sleman regency, Yogyakarta, Dukun district in Magelang, Selo district in Boyolali and Kemalang district in Klaten, the Jakarta Post reported.