Tanah Karo: An Indonesian volcano that had been dormant for more than four centuries erupted for the second day in a row Monday, spewing out towering clouds of ash and forcing the evacuation of more than 21,000 people.
Some airplanes had to be diverted because of poor visibility.
Villagers living along the slopes of Mount Sinabung in North Sumatra province have packed up their belongings and headed to emergency shelters, mosques and churches, said Andi Arief, a presidential adviser on disasters.
Their abandoned homes and crops were blanketed in heavy, gray soot, and the air was thick with the smell of sulfur.
Sinabung last erupted in 1600, so observers don`t know its eruption pattern and admitted over the weekend that they had not been monitoring it closely before it started rumbling days ago in the lead-up to Sunday`s first, less-powerful blast.
Like other volcanoes along the Sumatra fault line — the meeting point of the Eurasian and Pacific tectonic plates that have been pushing against each other for millions of years — it has the potential to be very destructive, said disaster researcher Erick Ridzky.
A larger blast has the potential to darken skies across the region, he said, affecting air traffic in nearby Singapore and Malaysia. Already, several domestic flights heading to the provincial capital of Medan had to be diverted, according to Bambang Ervan, spokesman for the Transportation Ministry.
"The problem is, we really have no idea what to expect," said Surono, a government volcanologist who uses only one name, after the mountain`s alert was raised to the highest level. "We don`t know what set it off, how long it will continue or whether we should expect pyroclastic flows or more powerful eruptions."
So far, 21,000 people have been evacuated, said Arief, and food, emergency tents, and medicine were on the way to the scene. The government also has set up public kitchens for refugees and handed out more than 17,000 respiratory masks.
Indonesia is spread across 17,500 islands and is prone to volcanic eruptions and earthquakes because of its location within the so-called "Ring of Fire" — a series of fault lines stretching from the Western Hemisphere through Japan and Southeast Asia.
It is also home to some of the largest eruptions in recorded history.
The 1815 explosion of Mount Tambora buried the inhabitants of Sumbawa Island under searing ash, gas and rock, killing an estimated 88,000 people.
Krakatoa in 1883, which was heard nearly 2,000 miles (3,200 kilometers) away, sent surges of gas and burning ash that, combined with a tsunami, left 36,000 dead.