WELLINGTON, New Zealand—The deafening boom that followed the violent eruption of an undersea volcano near Tonga acted like a warning bell for island residents to flee inland, a response that likely reduced the death toll when tsunami waves crashed the coastline not long after.
Tongan officials said the Pacific nation’s practice of running tsunami drills had also played a part in saving lives, even as the island archipelago sustained extensive damage to property, with the majority of houses on some islands being completely destroyed. The confirmed death toll from Saturday’s explosion and tsunami, which was felt as far away as the U.S. West Coast and Japan, so far is three.
Tsunami warning systems in the oceans are designed to detect waves caused by earthquakes and may not register the rarer event of a tsunami caused by an eruption. But some specific actions by Tonga’s meteorological service in the hours before the major eruption may have primed people to respond quickly to signs of danger or prompted them to stay away from the coastline.
Lesser eruptions at the undersea volcano were reflected in tidal gauges and prompted the agency to post cautionary information on its
page around sunrise on Saturday. In the late afternoon on Saturday, not long after a more significant eruption, it announced a tsunami warning for all of Tonga. Around the same time, thunder-like sounds were heard across the archipelago—a precursor to the cataclysmic explosion, and lightning could be seen.
“We expect tsunamis, tropical cyclones and earthquakes to happen on our islands,” said Lord Fatafehi Fakafanua, the speaker of Tonga’s parliament. “However, the reality is nobody expected a volcanic eruption of this magnitude.”
Out of 181 countries, Tonga ranks only behind Vanuatu and the Solomon Islands for its vulnerability to natural disasters in the World Risk Index, which informs planning by governments and other policy makers.
The explosion of the Hunga Tonga-Hunga Ha’apai volcano, located around 43 miles to the north of Tonga’s main island, shot ash and gas nearly 20 miles into the air, according to satellite data collected by the National Aeronautics and Space Administration. Much of that ash has fallen on Tonga’s islands, including airport runways and wharves, complicating initial efforts to reach and evacuate communities or bring them emergency supplies.
After reports of the eruption, a Red Cross disaster coordinator in Suva, Fiji, was on the phone to Marika Moala, a disaster coordinator on Tonga’s main island, Tongatapu, where three-quarters of the around 100,000 population lives. As they talked, Ms. Moala was running up and down one of Tonga’s few hills, helping people to get to higher ground.
“Big traffic jam in Tongatapu and police, Red Cross are helping traffic to move and get more people to higher ground,” said the notes of the conversation, which were provided by the Red Cross.
“Waves has (sic) come through the coastal side of the city toward the palace, but confirmed that they’re not huge damaging ones yet. More updates to come,” the notes say.
An Australian air force plane arriving in Tonga to deliver aid.
Photo:
Handout/Getty Images
Not long after the conversation, Tonga’s primary internet and telecommunications connection with the world was severed and it wasn’t until Wednesday morning that the Red Cross had contact with its Tonga team again.
Tsunami waves may have been as high as nearly 50 feet at islands closest to the volcano, according to a Tongan government statement. Some 43 miles south of the volcano at the capital Nuku’alofa, tidal gauges measured them at more than 3 feet. Despite being relatively low, they were powerful enough to cause severe property damage around the coast and toss vehicles.
“People tend to look at some of the footage and think the waves aren’t very big, but tsunami waves are very different,” said Katie Greenwood, head of the Pacific delegation of the International Federation of Red Cross and Red Crescent Societies. “They just push, push, push and each wave behind it brings more volume.”
Planes transporting aid from Australia and New Zealand landed in Tonga on Thursday after ash was cleared from the runway of a key airport. Water was among the supplies onboard, as sources such as stored rainwater have likely been contaminated with ash. A New Zealand navy vessel is expected to reach Tonga on Thursday, the government said, significantly expanding the scope of the humanitarian effort. A second New Zealand vessel, HMNZS Aotearoa, is expected to arrive on Friday and can produce more than 18,000 gallons of water a day through desalination.
Tonga is frequently battered by tropical cyclones and was also affected in 2009 by a tsunami that was centered on Samoa. Debris carried by tsunami waves also can kill.
Government officials and humanitarian organizations say this familiarity with natural disasters and continued preparedness likely contributed to the rapid reaction and saved lives. Despite being spread over dozens of islands, Tonga’s population is also tightly knit together by religion, extended family and respect for its monarchy.
The sound of the final eruption that triggered the tsunami was “like a bomb exploding,” said Marian Kupu, a reporter with radio station Broadcom Broadcasting.
“Our ears were ringing, we couldn’t even hear each other,” she said. “Personally I wasn’t scared,” she said. “The only thing that kind of scared us was that the disaster was different from the previous ones, which is always tropical cyclones.”
There is frequent conjecture in disaster, academic and wider circles about the effectiveness of tsunami warnings, said Ms. Greenwood. But in this case it seems clear that training and preparation in Tonga has reduced the catastrophic effects, she said.
Not everyone, however, could run from the waves.
Lisala Folau, who walks with the help of crutches, and a niece, were swept off tiny Atata island about 6 miles north of the capital Nuku’alofa, according to the transcript of an interview with Broadcom radio.
Mr. Folau clung to debris for hours, finally making it to shore at a village near the capital early Sunday morning, but his niece, Elisiva, didn’t survive.
“We floated at sea, just calling out to each other,” Mr. Folau said, according to the transcript. “It was dark and we could not see each other. Very soon I could not hear my niece calling any more.”
Write to Stephen Wright at [email protected]
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