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Distress signal detected in low******
An eruption occurs at the underwater volcano Hunga Tonga-Hunga Ha'apai off Tonga, on January 14, in this screen grab obtained from a social media video.。
A distress signal has been detected in a low-lying Tongan island following the volcanic eruption and tsunami, the United Nations said on Tuesday as the first death was reported.。
The UN Office for the Coordination of Humanitarian Affairs expressed concern for two islands, Mango and Fonoi, after surveillance flights confirmed "substantial property damage" from Saturday's eruption but there had been no contact with residents.。
"An active distress beacon had been detected from Mango," the OCHA said. The island is home to more than 30 people, according to Tongan census figures.。
The agency said extensive damage had been reported on the western beaches of Tonga's main island, Tongatapu, with several resorts and houses either destroyed or seriously damaged and two people were missing.。
No details of the missing were released but the brother of a British woman who was swept away by the tsunami said his sister's body had been found.。
Nick Eleini said the family was "devastated" that Angela Glover had died wile trying to rescue her dogs.。
"Earlier today my family was sadly informed that the body of my sister Angela has been found," Eleini said in a statement.。
Angela Glover, 50, and her husband lived in Tonga where she ran an animal welfare charity providing shelter and rehoming stray dogs.。
"I understand that this terrible accident came about as they tried to rescue their dogs," Eleini said.。
Three days after the eruption, information coming out of the Pacific archipelago is scarce with most communication links severed.。
New Zealand MP Jenny Salesa, whose electorate has a large number of Tongan residents, said everyone was praying for the people of Tonga.。
"They're really just worried about their safety," she told Radio New Zealand.。
"It's basically not knowing whether they are well, not knowing whether any of their family members are missing or (have) been washed out to sea. It's basically that lack of communication that is worrying to people back here in New Zealand."
The New Zealand and Australian air forces conducted surveillance flights over Tonga on Monday and were preparing further flights to carry emergency supplies to the Pacific kingdom.。
The OCHA said that while communication issues meant they could not fully assess the impact of the eruption and tsunami, there was concern about the contamination of drinking water and crops, and the need for safe water supplies.。
Greek divers discover Italian World War Two submarine wreck******
Greek divers have discovered the wreckage of an Italian submarine 80 years after it was sunk by the Allied Forces in the Aegean Sea during World War II.。
The Jantina, which had sailed from the Greek island of Leros with 48 sailors on board, sank on July 5, 1941, after being hit by torpedoes fired by British submarine HMS Torbay.。
She was discovered last month by Kostas Thoctarides, one of Greece's best-known divers, and his team, south of the island of Mykonos at a depth of 103 meters using a remotely operated underwater vehicle, the ROV Super Achilles, which carried out a detailed visual inspection of the wreckage.。
"Naval history is like a puzzle, and this is part of that puzzle," Thoctarides said. "The confrontation of two submarines is a rare naval event."
Jantina's identity was verified using records from Italy's Naval History Office, he said.。
She is the fourth submarine located and identified by maritime expert Thoctarides.。
How the Tonga eruption is helping space scientists understand Mars
NASA scientists say that the eruption of a submarine volcano in Tonga is helping them to understand how features formed on the surfaces of Mars and Venus.
The unusual explosion — which has been calculated at more than 500 times the force of the atom bomb dropped on Hiroshima, Japan, in 1945 — is offering researchers a rare chance to study how water and lava interact.
Studying the Hunga Tonga–Hunga Haʻapai volcano and its evolution in recent weeks is “important for planetary science”, says Petr Brož, a planetary volcanologist at the Institute of Geophysics of the Czech Academy of Sciences in Prague.
The knowledge “might help us to reveal results of water–lava interactions on the red planet and elsewhere across the Solar System”, he says.
The volcanic island, which began to form from ash and lava expelled from an undersea volcano in early 2015, piqued the interest of researchers including James Garvin, chief scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, because of its similarity to structures on Mars and possibly also Venus. “We don’t normally get to see islands form,” explains Garvin, but this one offered “a front-row seat”.
这座火山岛于2015年初由海底火山喷出的火山灰和熔岩开始形成，这激起了美国宇航局戈达德航天飞行中心首席科学家詹姆斯·加文（James Garvin）等研究人员的兴趣，因为它与火星上的结构相似，也可能与金星上的结构相似。 “我们通常不会看到岛屿形成，”加文解释说，但这个火山岛提供了“前排座位”。
Volcanic islands typically last for just months before being eroded away. But Hunga Tonga–Hunga Haʻapai survived for years, allowing Garvin’s team to use satellite observations and seafloor surveys to study how such islands form, erode and persist1. The researchers wanted to use that knowledge to understand how small conical volcanoes found on Mars may have formed in the presence of water billions of years ago.
Submarine eruptions differ significantly from those that occur on land, and can produce different landforms, says Brož. The presence of large quantities of sea water can make the explosions more violent, while also rapidly cooling the lava and restricting the amount of gas emitted from it.
Many volcanoes on Mars are thought to have erupted with steady flows of lava, but some could have been explosive, like Hunga Tonga–Hunga Haʻapai, says Joseph Michalski, a planetary scientist at the University of Hong Kong.
The marine environment also mimics some aspects of the low-gravity settings on small planets such as Mars and “can shed unique light on Martian features that formed in lower gravity”, he adds.
Last weekend’s violent explosion was preceded by a series of small eruptions starting in December, which increased the size of the island. That excited Garvin’s team. The researchers were in the process of submitting a paper describing the island’s slow erosion and a theoretical model for what makes it so stable — but “then BOOM. We had to hit reset,” says Garvin.
Teams around the world are now monitoring the island using optical, radar and laser satellites to measure what is left. The International Space Station’s Global Ecosystem Dynamics Investigation instrument has also collected data, says Garvin.
The vast majority of the island is now gone, says Daniel Slayback, a geographer at the Goddard Space Flight Center, who has visited Hunga Tonga–Hunga Haʻapai. “It’s kind of shocking to see,” he says. “It’s pretty dramatic.”
Garvin is hopeful that the giant chamber of magma deep under Earth’s crust that formed Hunga Tonga–Hunga Haʻapai will eventually create another island for researchers to study. If that happens, “we’ll measure it, and describe it and build a story about it”.