Thousands of tourists still stranded as Bali volcano continues spewing ash
A volcano with a deadly history is continuing to erupt on Bali, one of the world's most popular resort islands, spitting ash more than two miles high and stranding tens of thousands of tourists for a second day.
Lava is welling in the crater of Mount Agung, but it remains unclear how bad the eruption might be or how long it could last.
Authorities have raised the alert to the highest level and told 100,000 people to leave an area extending six miles from the crater as it belches grey and white plumes into the sky.
Agung's last major eruption in 1963 killed about 1,100 people.
Officials extended the closure of Bali's international airport for another 24 hours due to concerns that jet engines could choke on the thick volcanic ash, which was moving across the island.
Airport spokesman Ari Ahsanurrohim said more than 440 flights were cancelled on Tuesday, affecting nearly 60,000 passengers, about the same as Monday.
Without aircraft, getting in or out of Bali requires travelling hours by land and boat to an airport on another island.
Experts said a larger, explosive eruption is possible or Agung could stay at its current level of activity for weeks.
"If it got much worse, it would be really hard to think of. You've got a huge population centre, nearly a million people in Denpasar and surroundings, and it's very difficult to envision moving those people further away," said Richard Arculus, a volcano expert at Australian National University, adding that an eruption in 1843 was even more explosive than the one in 1963.
"There are many examples in history where you have this kind of seismic build-up - steam ejections of a little bit of ash, growing eruptions of ash to a full-scale stratosphere-reaching column of ash, which can presage a major volcanic event," he said.
A Nasa satellite detected a thermal anomaly at the crater, said senior Indonesian volcanologist Gede Swantika. That means a pathway from the storage chamber in the volcano's crust has opened, giving magma easier access to the surface.
Indonesian officials first raised the highest alert two months ago when a rash of seismic activity was detected at the mountain.
More than 100,000 people living near the volcano fled their homes, many abandoning their livestock or selling them for a fraction of the normal price. The seismic activity decreased by the end of October, prompting authorities to lower the alert level.
Tremors increased again last week and officials upped the alert and ordered another large-scale evacuation, with nearly 40,000 people now staying in 225 shelters, according to the Disaster Mitigation Agency in Karangasem.
Tens of thousands of villagers have remained in their homes because they feel safe or do not want to abandon their farms and livestock.
Flows of volcanic mud have been spotted on Agung's slopes, and Mr Arculus warned more are possible as it is the rainy season on Bali.
"They're not making a lot of noise. It's just suddenly coming like a flash flood out of nowhere," he said. "You do not want to be near them. Stay out of the valleys."
Indonesia sits on the Pacific "Ring of Fire" and has more than 120 active volcanoes.