Indonesia. Amid the ongoing eruption of Mount Merapi in Central Java, the authorities have warned that two other volcanoes are on heightened alert, while a third has produced 117 small eruptions since Wednesday.
The eruptions from Anak Krakatau, in the Sunda Strait, were audible as far as Serang district in Banten, about 40 kilometers away. The volcano is on Level 2 alert, meaning “beware.”
The two others, Mount Karangetang on Siau Island in North Sulawesi and Mount Ibu on Halmahera Island in North Maluku, are a level higher on “standby,” just one level below a full alert on Level 4.
Karangetang is considered the most active volcano in the archipelago, with 41 major eruptions since 1675. Its last eruption, on Aug. 6, is believed to have killed four people.
Hendrasto, an official from the Volcanology and Geological Disaster Mitigation Agency (PVMBG), said on Friday that Anak Krakatau, raised to Level 2 alert in October last year, had begun to erupt again last month.
He dismissed reports that Mount Galunggung in Tasikmalaya, West Java, and Mount Dempo in Pagaralam, South Sumatra, had exhibited increased volcanic activity as well.
State news agency Antara previously quoted Slamet, head of the Dempo monitoring post, as saying there had been dozens of volcanic earthquakes in the area. However, Hendrasto said the quakes were relatively small and would not affect the status of the volcano.
“Both volcanoes are on Level 1, which is the ‘normal’ level,” Hendrasto said.
“There have been some minor volcanic earthquakes, but those are still normal and simply indicate that the volcano is active.”
There are a total of 18 active volcanoes across the country.
In Sumatra, they include Mount Sinabung in North Sumatra, Talang in West Sumatra, Kaba in Bengkulu, Kerinci in Jambi and Anak Krakatau.
Sinabung began erupting on Aug. 29 after lying dormant for 400 years.
Its last major eruption, on Sept. 7, spewed volcanic ash more than 5,000 meters into the atmosphere.
The Level 2 volcanoes in Java are Papandayan in West Java, Slamet in Yogyakarta and Semeru and Bromo in East Java.
“Papandayan has been on ‘beware’ status since 2008, while Semeru’s level was reduced to Level 2 from Level 3,” Hendrasto said.
Also on Level 2 alert are Batur in Bali, Sangeang Api and Rinjani in West Nusa Tenggara, and Egon and Rokatenda in East Nusa Tenggara. Further east, we also have to “beware” of Soputan and Lokon in North Sulawesi, and Dukono and Gamalama in North Maluku.