BANGKOK/MANILA -- In an infamous incident in 1982, all four engines on a British Airways Boeing 747 failed when it encountered a dry cloud of volcanic ash from Indonesia's Mount Galunggung. "We are all doing our damnedest to get them going again," the captain told his passengers. "I trust you are not in too much distress." The crew succeeded, but not before the airliner had glided from 37,000 feet to 12,000 feet.
The chances of such an incident repeating itself have been virtually eliminated by better ground warning systems, improved avionics and the demands of aviation insurance, but volcanic disruption remains potentially immense. Some 100,000 flights were canceled over six days in April 2010 when Iceland's Mount Eyjafjallajokull fouled up busy trans-Atlantic corridors and European airspace, and 10 million travelers had flights canceled. A serious eruption in Southeast Asia could wreak havoc on the archipelagic, tourism-dependent economies of Indonesia and the Philippines, and affect routes to Australia and New Zealand.
Indonesia has more active volcanoes than anywhere else on earth, and therefore the most people living in proximity to them -- partly because fertile land is a common byproduct of eruptions. Fatalities have, however, been dramatically reduced. The Center for Volcanology and Geological Hazard Mitigation, or PVMBG, has upgraded monitoring and evacuations, and the National Disaster Mitigation Agency, established after the 2004 Indian Ocean tsunami, has improved overall disaster relief coordination. After Mount Agung came back to life in November, up to 140,000 people were moved to safe areas without incident.
The U.S. Geological Survey credits PVMBG with an "enviable" record. "Indonesia has had many more recent evacuations than any other nation, and fatalities have been avoided in all but a few eruptions," it said. Particularly dangerous are extended intermittent eruptions that tempt villagers into danger zones to tend fields and livestock. North Sumatra's Mount Sinabung has been erupting since 2013 and claimed the lives of 23 locals. Visitors who venture too close to fast-moving pyroclastic flows face certain death. In 2013, an eruption killed five climbers who had ignored warnings and ascended Mount Mayon in the lush province of Albay, southeast of Manila.
Government agencies must walk a fine line in addressing safety concerns without spooking precious tourists. Sometimes they get it wrong. In early 2005, the head of Thailand's Meteorological Department was dismissed for failing to issue a tsunami alert after misreading the situation. "We didn't think there would be subsequent seismic waves, because a similar quake of 7.6 on the Richter scale, which hit Sumatra [in November 2002] did not affect Thailand," a department official told reporters. The department's reticence was partly a result of its being excoriated earlier for damaging Thailand's tourism prospects by even mentioning tsunamis.
Building collapses are usually the most lethal component of an inland earthquake. Nepal's magnitude-7.8 temblor in April 2015 struck early in the morning as people slept, bringing down or damaging some 600,000 structures and killing over 9,000. The 2005 magnitude-7.6 quake in Pakistan left over 90,000 dead, including some 19,000 children who were killed in collapsing school buildings.
Japan's exemplary quake-resistant building codes are not replicated in much of Asia. Countries like Thailand and Malaysia rarely experience even minor tremors. In Indonesia, the public works ministry has codes for earthquake-proof structures, but implementation is questionable. An industrial zone along the coast of Banten Province four hours outside the capital contains chemical plants that lack earthquake mitigation. The environmental impact could be "enormous," Indonesian earthquake geologist Danny Hilman Natawidjaja said.
He highlighted the lack of evacuation drills in the event of quakes and tsunamis. "The Padang earthquake in 2009 is a disastrous example of how evacuation education failed. Fearing tsunami, they used cars instead of running on foot to higher places -- resulting in traffic gridlock."
The Philippines may also be at risk. If the feared West Valley Fault generated a magnitude-7.2 quake in Manila, it would bring down an estimated 170,000 residential buildings and 10% of government structures, killing or severely injuring over 150,000 people there and a further 50,000 in surrounding areas. "The first thing you need to do is a retrofitting program, but it is not as easy as you think," Renato Solidum, head of the Philippine Institute of Volcanology and Seismology, told the Nikkei Asian Review.
Although President Rodrigo Duterte has not alluded to earthquakes again since his address in July, Clark Green City has been given priority for Manila's decongestion and disaster preparedness. The former U.S. military base 100km north of Manila is being developed as an alternative administrative site. The transportation ministry moved there in July last year, and construction of a backup government center has begun.
Nikkei staff writers Cliff Venzon in Manila and Erwida Maulia in Jakarta contributed to this report.