On January 15, an undersea volcano erupted violently on the island of Hong Aha Apay in the South Pacific island nation of Tonga, spewing ash and steam 19 kilometers into the atmosphere, forming a huge mushroom cloud. According to the BBC, the sound of the eruption spread throughout the South Pacific, and even some residents as far away as the United States heard the sound of the eruption.
The volcano triggered a transoceanic tsunami that devastated the Tongan capital. Japan has issued consecutive tsunami warnings, the first Tsunami warnings since November 2016. New Zealand, the United States, Canada, Fiji around Tonga, and Samoa have also issued tsunami warnings of different levels.
Tonga "lost contact" under the tsunami
On Saturday evening local time, the sky in Tonga was obscured by a cloud of volcanic ash, as if it were night, and volcanic ash fell from the sky. In the afternoon, huge waves swept through Tonga's waterfront streets and buildings, and a 0.8-metre-high tsunami was observed locally. Residents have fled to higher ground, King Tupou VI of Tonga has been evacuated from the palace, and electricity and internet have been cut off almost completely.
Data map: January 15, 2015 local time, Tonga, Hong Aha Apay Island volcanic eruption scene. Figure/IC photo
The United States Geological Survey (USGS) estimates that the tsunami caused by the volcano is equivalent to an earthquake of magnitude 5.8. As local networks remain unstable and there are currently no reports of damage caused by the tsunami, Tongans abroad are also very anxious.
Some aid agencies said authorities required people to wear masks and drink bottled water under the extremely thick ash and smoke. New Zealand Prime Minister Ardern said Tonga's capital was covered in thick volcanic ash, polluting local water sources and fresh water was a key need.
New Zealand was still unable to send military reconnaissance aircraft on Sunday because of the ash cloud at 19 kilometres, and they hoped to send military reconnaissance aircraft to Tonga on Monday, followed by resupply aircraft and naval vessels.
According to the Associated Press, because Tonga has not experienced a COVID-19 outbreak so far, its international aid situation is somewhat complicated. But Ardern said New Zealand's military personnel had been fully vaccinated against COVID-19 and expressed a willingness to abide by any vaccination agreement designated by Tonga.
United Nations Secretary-General António Guterres is deeply concerned about this. The United Nations Office for the Pacific region is also closely monitoring the situation and will provide support when needed.
Underwater volcanoes continue to erupt
The Beijing News reporter learned today (January 16) from the Tsunami Warning Center of the Ministry of Natural Resources that according to the statistical analysis of historical volcanic activity events, the current eruption activity may last for weeks or months.
The volcano is located about 30 km south-east-east of The Island of Funu Afoou in Tonga, on the subduction boundary between the Pacific Plate and the Indo-Australian Plate, and is part of the volcanic arc of the Tonga-Kolmadec Islands. The volcano was formerly an undersea volcano that erupted in 2009 to form a new island. The volcano has erupted several times in 2014, 2015, 2019 and 2021. As of January 16, 2022, volcanic eruptions continue.
On January 15, 2022 local time, satellite images released by the New Zealand High Commission showed images of the eruption of a volcano under the tonga seaflo. Figure/IC photo
According to local tonga media (Matangi Tonga news), when the volcano began to erupt earlier on the 14th, scientists had observed large-scale explosions and lightning around the volcano.
Planet Labs, a company that has been observing the volcano since last December, has taken satellite images showing that ash has formed an expanding island near Tonga. "The area of the island has almost expanded by almost 45% due to volcanic ash."
Hans Schwaiger, a geophysicists research institute at the Alaska Volcano Observatory, explains that there is not much difference between the undersea volcano and the volcano on the ground, but when the underwater volcano erupts, the sea water increases the explosiveness of the eruption.
The volcanic activity affected many countries
It is not only Tonga that has been affected by this eruption. According to the latest monitoring results, the Tsunami Warning Center of the Ministry of Natural Resources analyzed that the volcanic eruption triggered a transoceanic tsunami that affected the entire Pacific coastal region.
Countries along the Pacific coast, such as Chile, Japan and New Zealand, have monitored significant tsunami waves, with a maximum tsunami wave amplitude of 1.5 meters. Tsunami waves were monitored in the coastal waters of China in the early morning of the 16th, of which the largest tsunami amplitude at Shipu Station in Zhejiang Province was about 20 cm, and the tsunami amplitude at the rest of the tide stations was less than 15 cm. This process did not have a catastrophic impact on china's coast.
The Japan Meteorological Agency said that at 23:55 on the 15th, a tsunami of 1.2 meters was observed in Amami City, Kagoshima Prefecture, Japan, and then a tsunami of less than 1 meter was observed in a large area on the Pacific side. The Meteorological Agency warned of repeated arrivals and called on local residents to stay in safety until the alarm was lifted. At 2:26 local time on the 16th, a 1.1-meter tsunami was also observed in Kuci Port, Iwate Prefecture, Japan.
On January 16, 2022, local time, in Murdo City, Kochi Prefecture, Japan, drone aerial photographed the local port, and some ships capsized. Figure/IC photo
Japan has issued consecutive tsunami warnings. At 00:15 local time on the 16th, the Japan Meteorological Agency issued a tsunami warning for the Amami Islands and the Tugalla Islands, and at the same time issued a tsunami alert to the Pacific coastal areas of the Japanese archipelago. At 2:26 a.m., the tsunami tide level was observed at Kuci Port in Iwate Prefecture, and the Meteorological Agency subsequently issued a tsunami warning for Iwate Prefecture by 3:00 p.m.
Tonga's neighboring countries Fiji and Samoa subsequently issued tsunami warnings, as well as tsunami warnings on the west coast of the United States and the state of Hawaii, British Columbia in Canada, and the North Island of New Zealand.
In California, U.S., local residents saw waves rise several feet in minutes. In southern California, waves have damaged local boats, flooded low-lying streets and parking lots, and floated vehicles on the water.
Dave Snider, tsunami early warning coordinator at Alaska's National Tsunami Warning Center, said authorities in Hawaii, Alaska and the Pacific Coast advised residents to move to higher shorelines and heeded instructions from local officials.
Snyder noted, "We've never issued an alert within such a long stretch of coastline, and I can't remember exactly when it was last time." He added that the event of a volcanic eruption affecting an entire ocean basin is highly unusual, but he also predicts that the tsunami situation in the United States and the rest of the world will continue to improve.
Japan has lifted all tsunami warnings.
Beijing News reporter Hou Wuting Zhang Jianlin
Edited by Lei Zhang Proofreader Lucy