Wellington (AFP) - Tonga finished removing a thick coat of volcanic ash from an international runway Wednesday after days of painstaking effort, clearing the way for desperately needed emergency aid to arrive in the isolated, disaster-stricken nation.
UN crisis coordinator Jonathan Veitch told AFP the runway on the Pacific kingdom's main island, once buried in five to 10 centimetres (two to four inches) of ash, was again operational.
It is "cleared but not in use yet", he said, adding that Tonga could receive much-stalled flights from Australia and New Zealand from Thursday.
Three people were killed when the Hunga Tonga-Hunga Ha'apai volcano exploded on Saturday, triggering tsunami waves that ripped down homes and caused widespread flooding.
The overwhelmed Tongan government has called the dual eruption-tsunami "an unprecedented disaster" and reported that waves as high as 15 metres (50 feet) destroyed almost every home on some outlying islands.
More than 80 percent of the archipelago's population of 100,000 have been impacted by the disaster, the United Nations said Wednesday, and initial assessments indicate an urgent need for drinking water.
When the underwater caldera exploded, it fired debris 30 kilometres (19 miles) into the air and deposited ash and acid rain across the kingdom of 170 islands -- poisoning water supplies.
"Water supplies across Tonga have been severely impacted by ashfall and saltwater from the tsunami," said Katie Greenwood of the International Federation of Red Cross and Red Crescent Societies.
She said there was a "mounting risk of diseases such as cholera and diarrhoea".
Cleared for landing
For days, Australia and New Zealand have had military transport C-130 aircraft laden with supplies ready to go.
But Tonga authorities were only able to clear about 100-200 metres of the runway daily.
Ash particles pose a threat to modern jet aircraft, including by melting and accumulating in the engines.
Both countries have also sent help by sea, with Royal New Zealand Navy ships HMNZS Wellington and HMNZS Aotearoa expected to arrive in Tongan waters Friday.
They are carrying water supplies and a 70,000-litre-a-day desalination plant, as well as navy hydrographic and dive personnel to survey shipping channels.
Australia's helicopter landing vessel HMAS Adelaide is expected to soon set sail to the disaster zone.
China also said it would send emergency supplies.
"Relief efforts are scaling up, but it is difficult to reach remote areas to assess people's needs and provide assistance, and there are logistical challenges" with relief deliveries, UN spokesman Stephane Dujarric said Wednesday in New York.
There are fears for the island's food supplies, with a tearful national assembly speaker Fatafehi Fakafanua saying "all agriculture is ruined".
"It's very sad to hear, so on top of the water that we need in Tonga, it seems that we'll be facing a food shortage," he told the Pacific Media Network.
Incommunicado
The eruption was one of the most potent in decades, releasing a pressure wave that traversed the planet, travelling at supersonic speeds of about 1,230 kilometres per hour, New Zealand's National Institute of Water and Atmospheric Research said.
It broke a vital undersea communications cable that links Tonga with the rest of the world.Partial communications were restored Wednesday with mobile phone network provider Digicel announcing "international calls service is back up".
There had been little news from the islands since Saturday, except for a handful of messages delivered through satellite phones, with a complete restoration of services weeks away.
"US cable company SubCom advises it will take at least four weeks for Tonga's cable connection to be repaired," New Zealand's foreign ministry said.
The Red Cross finally reached its team in Tonga via satellite phone Wednesday.The organisation sent an emergency team to the hard-hit islands of Mango, Fonoifua and Namuka.
A village on Mango was destroyed, and only a few houses remained standing in several other villages across the archipelago, authorities said.
Neighbouring countries have relied on surveillance flights and satellite images to assess the scale of the disaster.
The latest images showed vast areas covered in ash, roads inundated, walls toppled and buildings smashed.
Satellite images show there is now open water where most of the volcanic structure stood above sea level before the eruption.
A 65-year-old woman in Mango was one of three people confirmed dead, along with a 49-year-old man and a British national.Multiple injuries were also reported.
Tongan navy vessels carrying health workers and supplies of water, food and tents were being deployed.
"The evacuation process has begun," the government said.
Tongans abroad have been mobilizing to help.
Olympian Pita Taufatofua launched a GoFundMe campaign which has raised more than US$350,000.Other athletes have also set up relief campaigns online.
The volcano disaster is likely to "knock Tonga back a few steps," Tongan rugby international Ben Tameifuna told AFP."Tonga is going to take as much help as it can."
