In this satellite image taken by Himawari-8, a Japanese weather satellite, and released by the agency, shows an undersea volcano eruption at the Pacific nation of Tonga, Jan 15, 2022. (PHOTO / JAPAN METEOROLOGY AGENCY VIA AP)
Days after Pacific island nation of Tonga was devastated by a massive eruption of an underwater volcano emergency aircraft from Australia and New Zealand were still unable to land due to a thick blanket of volcanic dust now covering the islands.
The eruption on Jan 15 had triggered a Pacific-wide tsunami alert and cut off all communications with the island kingdom.
China and several other countries had offered help to Tonga with Chinese Foreign Ministry spokesperson Zhao Lijian saying that the Red Cross Society of China had decided to provide $100,000 of emergency humanitarian aid in cash
China and several other countries had offered help to Tonga with Chinese Foreign Ministry spokesperson Zhao Lijian saying at his regular press briefing on Jan 17 that the Red Cross Society of China had decided to provide $100,000 of emergency humanitarian aid in cash.
READ MORE: Tsunami-hit Tonga suffered extensive damage, fears death toll to rise
He said China was closely monitoring the situation and had expressed “deep sympathies and sincere condolences” to the government and people of Tonga.
The eruption took place off the small island of Hunga-Tonga-Hunga-Ha’apai about 65 km north of Tongatapu, Tonga’s main island and home to many of the Pacific nation’s 105,000 residents.
With limited communications from Tongatapu to the outside world, damage is said to be widespread with no information as to how many people may have died. Tonga is made up of 170 islands and atolls with many of them uninhabited.
This combination of this satellite images provided by Maxar Technologies shows an overview of Hunga Tonga Hunga Ha'apai volcano in Tonga on April 10, 2021, top, on Jan 6, 2022, middle, and Jan 18, 2022, showing what’s left after the Jan 15 eruption. (SATELLITE IMAGE ©2022 MAXAR TECHNOLOGIES VIA AP)
Richard Arculus, a volcanologist with the Australian National University in Canberra, said it will take some time to gather all the data, but on the Volcanic Explosivity Index, which measures the explosiveness of volcanic eruption, it would be on par with the Mount Pinatubo eruption in the Philippines in 1991, and the Krakatoa incident in 1883, in Indonesia’s Sunda Strait, which killed more than 36,000 people and generated a 37-meter high tsunami.
Both those eruptions were around 5 to 6 on an index of 1 to 8.
"You rarely get a chance to see a volcano explode. (As) a satellite was just overhead at the time, (it) caught the full impact and power of the explosion," Arculus said, referring to the latest Tonga incident.
He said debris from the explosion was thrown 20 kilometers into the atmosphere.
Arculus had been part of a research team that mapped some 40 underwater volcanoes around the Tongan chain of islands in 2004.
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Scientists said the explosion could be heard in Alaska, over 9,000 km away, and that the sound wave spread out across the Pacific at 1,200 km an hour.
Measuring around 1,800 meters high and 20 km wide, the Hunga-Tonga-Hunga-Ha'apai volcano was hidden under the water. Satellite imagery on Jan 17 showed ash covering the whole of Tonga and parts of Fiji, New Caledonia, Vanuatu and Samoa.
Shane Cronin, a professor of vulcanology with the department of earth sciences at the University of Auckland, said the Hunga-Tonga-Hunga-Ha'apai volcano has erupted regularly over the past few decades. But those eruptions were small, dwarfed in scale by the latest incident.
Writing for the academic website The Conversation, he said: “Our research into these earlier eruptions suggests this is one of the massive explosions the volcano is capable of producing roughly every thousand years.”
Andrew Tupper, principal consultant with Natural Hazards Consulting, an Australia-based hazard warning and response consultancy, said the volcanic eruption near Tonga only reinforces the urgent need “for global cooperation on hazards of all kinds.”
“The eruption produced ash, gas, acid rain, tsunami and more. The tsunami wave heights were partially tracked through tide gauges that Australia has supported in the Pacific, and the atmospheric clouds through satellite data operated and shared by Japan and others,” Tupper told China Daily in an email.
“Our cooperation as a global community helps us all manage these events, including the impacted countries. But there’s lots more to do as we work to manage natural hazards together, better, globally.”
Heather Handley, a volcanologist and adjunct associate professor at Monash University in Melbourne, said the volcano is located in the Tonga-Kermadec volcanic arc and part of the so called "Pacific Ring of Fire".
“Here at the plate boundary the Pacific Plate is being pushed down and under the Indo-Australian Plate,” she said in an email.
This handout photo taken on January 17, 2022 and received on Jan 18 from the New Zealand Defence Force shows crew on a P-3K2 Orion aircraft surveying an area in Tonga, after the eruption of the Hunga-Tonga – Hunga-Haa'pai volcano on Jan 15.
(HO/ NEW ZEALAND DEFENCE FORCE / AFP)
“The down going plate heats up as it descends and starts to 'sweat'. This releases fluids into the overlying mantle and causes it to melt. The fluid-rich magma then rises to the surface to form a volcano and the fluids involved in the formation of the magma form gas bubbles at shallower levels in the crust and fuel explosive eruptions in these tectonic settings.”
Handley said it is unclear “at this stage” whether the influx of seawater into the vent added to the explosiveness of the eruption.
“What we don’t know is whether the volcano will produce another large-scale eruption or whether activity will decline. But volcanic activity, however, is likely to continue over the coming days,” she said.
Chris Firth, a volcanologist with Macquarie University, said apart from tsunamis, the other major cause for concern will be what he called “ash-fall”, alluding to worries about layers of ash falling on neighboring islands.
“This ash covers buildings and infrastructure making recovery difficult, buries gardens and impacts plants with consequences for food supply, and is likely to contaminate water supplies. Ash is also hampering rescue and relief efforts as aircraft cannot fly through it,” he said.
“The volcano appears to have quietened (down) for now. However, eruptions of this magnitude are not usually over so quickly and the volcano may continue to be active over coming weeks or months,” Firth added.
karlwilson@chinadailyapac.com