Following the eruption on the 14th local time, the submarine volcano of Hunga Tonga-Hunga Ha'apai in the South Pacific island nation of Tonga re-erupted again on the 15th. Soon after, a four-foot -tall tsunami hit the Tonga capital, Nuku'alofa, and people flocked to higher ground, witnesses said they were accompanied by volcanic ash falling from the sky.
According to foreign media reports, the extent of casualties or losses due to the interruption of communications in the country is still difficult to assess.
According to the Mainichi Keizai Shimbun, the scale of the eruption is very large, and the energy released is about the same as 1,000 Hiroshima atomic bombs. "China Meteorological Enthusiasts" posted that this may be one of the world's strongest volcanic eruptions since Pinatubo in the Philippines in 1991.
↑ Hon Aha Apay Island volcanic eruption.
At present, the tsunami caused by this "epic" volcanic eruption has reached many countries along the Pacific coast. According to the latest news of the CCTV news client on the 16th, according to the global water level monitoring data, the volcanic eruption triggered a transoceanic tsunami, affecting the entire Pacific coastal region. In short, this eruption of a volcano in the South Pacific has stirred up nearly half the planet. So why is this eruption so violent? What happens next?
Stir up nearly half the planet
As of 11:30 a.m. on January 16, 2022 (Beijing time), countries such as Chile, Japan and New Zealand on the Pacific coast 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.
More than 800 kilometers away in Fiji, "great thunder" can be heard. New Zealand, more than 2,300 kilometres away, has issued warnings about storm surges triggered by volcanic eruptions, and "strong winds and unusual waves may occur in parts of the country". A New Zealand weather forecaster tweeted: "The energy release (from the eruption) is simply amazing, and it is said that sonic booms have been heard all over New Zealand. ”
↑ On January 16, Tutukaka, New Zealand, a tsunami warning was issued after a volcanic eruption, and fishing boats at the pier were seriously damaged.
In addition, the tsunami also reached Santa Cruz, California, 4,000 kilometers away, and the sea rose and flooded into people's homes, and there were also large waves along the coast. On January 15, local time, the Chilean Naval Marine Survey bureau reported that the tsunami had reached the Pacific coast of northern Chile in the afternoon of the same day, and a number of coastal cities were hit by huge waves of more than two meters, and some urban areas were inverted with seawater.
↑Image of an undersea volcano eruption in Tonga taken by the Japanese meteorological satellite Haima 8 on January 15.
Japan, which is 8,000 kilometers away, has also been affected, and the Japan Meteorological Agency has continuously issued tsunami warnings in the early morning of the 16th. This is the first time Japan has issued a tsunami warning since November 2016. According to the height of the tsunami observed at the observation point in Iwate Prefecture, The highest of Kuchi Port is 1.1 meters, the kamaishi is 40 centimeters, the Big Boat Ferry is 30 centimeters, and the Miyako is 40 centimeters.
A "once-in-a-millennium" massive volcanic eruption
The Hunga Tonga-Hunga Ha'apai volcano is reportedly part of the volcanic arc of the highly active Tonga-Kemadek Islands and is located 65 kilometers north of Tonga's capital, Nuku'alofa, at an altitude of about 100 meters. But hidden beneath sea level is a giant undersea volcano about 1,800 meters high and 20 kilometers wide.
The submarine volcano has erupted regularly over the past few decades, only to "surface" after the 2009 eruption to form a new island. One of the most serious eruptions was in late 2014 and early 2015, when the volcano erupted several times and paralyzed Tonga's air traffic. It was after this eruption that Hunga Tonga-Hunga Ha'apai was born.
↑This submarine volcano did not "surface" until 2009.
Shane Cronin, a volcanologist at the University of Auckland, explained that the eruptions in late 2014 and early 2015 formed a new volcanic cone that connected the nearby islands of Hunga Tonga and Hunga Ha'apai to form an island about 5 kilometers long.
According to CCTV News, after December 20, 2021, the volcano suddenly began to be active, but on January 11 this year, it entered a brief dormancy period, followed by two consecutive days of eruption on the 14th and 15th.
Cronin said the eruption was one of the largest volcanic eruptions in Tonga in the past 30 years, "spreading horizontally and producing a lot of ash." He also pointed out that this is also one of the large-scale eruptions of the volcano".
↑ According to reports, hidden under sea level is a huge submarine volcano about 1800 meters high and 20 kilometers wide. Picture according to "Chinese meteorological enthusiasts"
He explained that researchers found evidence of the past two large-scale eruptions in the Hunga crater in sediments on the ancient island. "We found that these chemical compositions matched volcanic ash deposits on Tongatapu Island, the largest island 65 kilometers away, and then determined by radiocarbon dating that large-scale volcanic eruptions occurred approximately every 1,000 years, the last time in 1100 AD." Cronin said.
Given this information, the January 15 eruption appears to fit the timeline for a "mass eruption."
Experts: Previously, small eruptions were "charged" for larger eruptions.
"Looking back at the chemical processes of past volcanic eruptions, we now believe that small-scale volcanic eruptions mean that magmatic systems are slowly accumulating themselves in preparation for large-scale eruptions." Cronin said.
"We examined the volcanic islands in 2016 and found that these historical eruptions were just a prelude to important events." he said. While mapping the seafloor, they found a crater hidden 150 meters underwater — a crater-like depression about 5 kilometers in diameter. He explained that small eruptions such as those in 2009 and 2014/15 occurred mainly at the crater rim, but large eruptions came from the crater itself, and the power of the large-scale eruptions caused the erupting magma to collapse inwards, further deepening the crater.
According to the news released by "Chinese meteorological enthusiasts", a few days before the volcanic eruption on January 15, 2022, Hunga Tonga-Hunga Ha'apai (Hunga Tonga-Hunga Ha'apai) rose sharply and then collapsed rapidly, and there are many indications that the island has completely disappeared after the eruption.
↑ There are many indications that the island of Hong Aha Apay has completely disappeared after this volcanic eruption. Picture according to "Chinese meteorological enthusiasts"
In general, Cronin explains, when the magma of an undersea volcano slowly rises into seawater, a vapor film forms between the magma and the water, even at temperatures as high as 1200°C. This film provides an insulating layer to the outer surface of the magma, allowing it to cool. However, when magma filled with volcanic gas erupts from the ground, the magma quickly enters the water, quickly destroying the vapor film, bringing the hot magma into direct contact with cold water.
Volcano researchers call this the "fuel coolant interaction," which resembles a weapons-grade chemical explosion. Extremely violent explosions tore the magma apart, triggering a chain reaction in which new magma fragments exposed the hot internal surface to water, and the explosions were repeated repeatedly, eventually spewing out volcanic particles, causing supersonic explosions.
↑"Volcanic Eruption Intensity Index" (VEI) in relation to volcanic ash quantities. The VEI6 eruption of Mount Pinatubo in the Philippines was the strongest eruption in nearly a century.
"Chinese meteorological enthusiasts" posted that all indications are that the intensity of this volcanic eruption is likely to reach the upper end of the "Volcanic Eruption Intensity Index" (VEI) level 5, and may even reach VEI6, which may be one of the strongest volcanic eruptions in the world since Pinatubo, Philippines, in 1991.
Latest: Seismic activity is strengthening again The submarine volcano may erupt again
Volcanic eruptions have reportedly continued as of January 16, 2022. Cronin warned that studies of historical eruptions of the same volcano suggest that current eruptions could last for weeks or months. The people of Tonga must be alert to further volcanic eruptions, "especially tsunamis that occur in a short period of time, and should avoid low-lying areas." ”
According to the latest news from "China Meteorological Enthusiasts", the Suva Seismic Observatory in Fiji, which is approaching in recent hours, has observed another strengthening trend in seismic activity, suggesting that submarine volcanoes may erupt again.
In addition, as one of the strongest volcanic eruptions in the past 30 years, the volcanic eruption of Tonga will have some climatic effects. The climate of southern Australia, southern Brazil, New Zealand, Argentina, Chile and South Africa will bear the brunt of the climate in the mid-to-high latitudes of the southern hemisphere; volcanic eruptions are located near the ENSO monitoring area, and the volcanic eruptions are remotely correlated through the sea and air, affecting wind currents, and even adding fire to the La Niña turn neutral trend to spawn El Niño.
Red Star News reporter Xu Huan
Edited by Zhang Xun
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