CIGONDONG, INDONESIA/JAKARTA – As Indonesia reels from the carnage of yet another natural disaster, authorities around the globe are working on how they can prepare for the kind of freak tsunami that battered coasts west of Jakarta last month.
The Dec. 22 tsunami killed around 440 people along the coastlines of the Sunda Strait, capping a year of earthquakes and tsunami in the vast archipelago, which straddles the seismically active Pacific Ring of Fire.
No sirens were heard in those towns and beaches to alert people before the deadly series of waves hit shore.
Seismologists and authorities say a perfect storm of factors caused the tsunami and made early detection nearly impossible, given the equipment in place.
But the disaster should be a wake-up call to step up research on tsunami triggers and preparedness, said several of the experts, some of whom have traveled to the Southeast Asian nation to investigate what happened.
“Indonesia has demonstrated to the rest of the world the huge variety of sources that have the potential to cause tsunamis. More research is needed to understand those less-expected events,” said Stephen Hicks, a seismologist at the University of Southampton.
Most tsunami on record have been triggered by earthquakes. But this time it was an eruption of the Anak Krakatau volcano that caused its crater to partially collapse into the sea at high tide, sending waves up to 5 meters (16 feet) high smashing into densely populated coastal areas on Java and Sumatra islands.
During the eruption, an estimated 180 million cubic meters — around two-thirds of the less-than-hundred-year-old volcanic island — collapsed into the sea.
But the eruption didn’t rattle seismic monitors significantly, and the absence of seismic signals normally associated with tsunami led Indonesia’s geophysics agency (BMKG) initially to tweet there was no tsunami.
Muhamad Sadly, head of geophysics at BMKG, later said that its tidal monitors had not been set up to trigger tsunami warnings from nonseismic events.
The head of Japan’s International Research Institute of Disaster, Fumihiko Imamura, said he did not believe that Japan’s current warning system would have detected tsunami like the one in the Sunda Strait.
“We still have some risks of this in Japan … because there’s 111 active volcanoes and low capacity to monitor eruptions generating a tsunami,” he said in Jakarta.
Scientists have long flagged the collapse of Anak Krakatau, around 155 km (100 miles) west of the capital, as a concern. A 2012 study published by the Geological Society of London deemed it a “tsunami hazard.”
Anak Krakatau emerged from the Krakatoa volcano, which in 1883 erupted in one of the biggest explosions in recorded history, killing more than 36,000 people in a series of tsunami and lowering the global surface temperature by 1 degree Celsius (1.8 Fahrenheit) with its ash.
Broken warning system
Some experts believe there was enough time for at least a partial detection of last month’s tsunami in the 24 minutes it took waves to hit land after the landslide on Anak Krakatau.
But a country-wide tsunami warning system of buoys connected to seabed sensors has been out of order since 2012 due to vandalism, neglect and a lack of public funds, authorities say.
“The lack of an early warning system is why Saturday’s tsunami was not detected,” said disaster agency spokesman Sutopo Nugroho, adding that of 1,000 tsunami sirens needed across Indonesia, only 56 are in place.
“Signs that a tsunami was coming weren’t detected, and so people did not have time to evacuate.”
Nugroho said Monday that the death toll from the Dec. 22 tsunami had risen to 437, and the number of the injured had doubled to slightly over 14,000. He put the number of displaced people at nearly 34,000. Sixteen people were listed as missing.
President Joko Widodo last week ordered BMKG to purchase new early warning systems, and the agency later said it planned to install three tsunami buoys on the islands surrounding Anak Krakatau.
The cost of covering the country is estimated at 7 trillion rupiah ($481.10 million). That is roughly equivalent to Indonesia’s total disaster response budget of 7.19 trillion rupiah for 2018, according to Nugroho.
But other experts say that even if this network had been working, averting disaster would have been difficult.
“The tsunami was very much a worst-case scenario for any hope of a clear tsunami warning: a lack of an obvious earthquake to trigger a warning, shallow water, rough seabed and the close proximity to nearby coastlines,” said seismologist Hicks.
In the Philippines, Renato Solidum, undersecretary for disaster risk reduction, said eruptions from the country’s Taal volcano had caused tsunami before in the surrounding Taal Lake.
He said that what happened in Indonesia showed the need to “re-emphasize awareness and preparedness” regarding volcanic activity and its potential to trigger tsunami in the Philippines.
The United States has also suffered several tsunami caused by volcanic activity, including in Alaska, Hawaii and Washington state, according to the national weather service.
In Indonesia last year, a double quake-and-tsunami disaster killed over 2,000 people on Sulawesi island, and at least 500 more died when an earthquake flattened much of the northern coastline of the vacation island of Lombok.
Another active Indonesian volcano, Mount Agung, erupted Sunday on Bali, belching ash high into the air and over nearby villages. Mount Agung has been erupting periodically since it rumbled back to life in 2017, when it grounded hundreds of flights and left 120,000 visitors stranded.
In a country where, according to government data, 62.4 percent of the population is at risk of being struck by earthquakes and 1.6 percent by tsunami, attention is now focused on a continued lack of preparedness.
“Given the potential for disasters in the country, it’s time to have disaster education be part of the national curriculum,” Widodo told reporters after the latest tsunami.
For Ramdi Tualfredi, a high school teacher who survived last month’s waves, these improvements cannot come soon enough.
He said that people in his village of Cigondong on the west coast of Java and close to Krakatau had never received any safety drills or evacuation training.
“I’ve never received education on safety steps,” he said.
“The system … totally failed.”