In January 2022, Tonga experienced a volcanic eruption confirmed to be the most enormous explosion that has even been documented through modern methodologies and instrumentations.
The impacts of the record-breaking Tonga eruption were so substantial that a subsequent tsunami occurred. Other than that, about 85,000 individuals were directly affected by the catastrophe. Given Tonga’s small population of just over 100,000, this number comprised a vast majority of the country’s entire population.
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The country had to shell out millions of dollars to deal with this devastating event. However, it may take a while for scientists to understand what occurred in this catastrophic eruption and what it speaks about potential volcanic threats and risks.
An unfamiliar volcanic eruption
Stationed satellites were able to capture the blast’s immense power. These observations have challenged accepted ideas and notions about eruptions and their physics. Numerous researchers experienced difficulties explaining why the volcano released a plume to such heights and yet emitted lesser amounts of ash than expected. Moreover, the ripples of shock waves across the ocean and atmosphere were unlike anything previously documented in today’s scientific community.
This eruption has forcibly led scientists to reconsider their previous ideas and notions about the risks posed by submarine volcanoes in the Pacific Ocean. Nico Fournier, a GNS Science, mentioned that this event “rips the Band-Aid on our lack of understanding of what’s happening underwater.”
Further understanding of the Tonga eruption
That being said, it has been roughly five months since the peak eruption occurred. In those months, researchers have started to gather findings on why the submarine volcano had such an explosive eruption and devastating aftermath. Evidence obtained by two research groups suggests that when the volcano’s center was collapsing, the volcano released a vast quantity of magma that violently reacted with the water. This led to the powering of numerous strong explosions and hundreds of smaller blasts.
Last May, volcanologist Shane Cronin from the University of Auckland spearheaded a team that traversed through the submarine volcano’s caldera. They noted that the caldera that was 4km wide had reduced its depth. Initially 200 meters below sea level, the depth was extended to more than 850 meters.
Cronin suggested that the enormous explosion could be attributed to the interactions between the water and the large quantities of magma when the eruption started. The immense temperature difference between the two meant that an explosion resulted as the water forcibly was in contact with the released magma. Cronin mentioned that each interaction had pushed water further into the magma’s edges. This, in turn, expanded the contact area and drove more explosions consecutively.
This work was presented in Vienna during the EGU (European Geosciences Union) meeting on May 26, 2020.
A separate group from New Zealand’s NIWA (National Institute for Water and Atmospheric Research) also studied the site. They took samples of ash from the volcano’s surrounding sea floor. Their samples revealed that the devastating eruptions were probably succeeded by dynamic pyroclastic flows, fiery ash streams, and lava that had rained down the caldera’s submerged sides. Team leader and marine geologist Kevin Mackay shared that the hot ash onrushing had turned the surrounding sea floor into a white desert that seemingly wiped out everything.
They noted how it seemed like nothing on the sea floor was able to survive. However, the samples are still undergoing analysis to gauge the damage. NIWA biogeochemist Sarah Seabrook shared that the collected samples are used to study the potential effects on ocean acidification and oxygen levels.
The future of Tonga
Tonga was left devastated by the eruption. The good news is that rebuilding and restoration have been taking place. Moreover, residents of affected nearby islands were offered a place by the king of Tonga where they could relocate.
Is the Tonga volcano still erupting?
On December 20, 2021, an eruption began on Hunga Tonga – Hunga Ha’apai, a submarine volcano in the Tongan archipelago in the southern Pacific Ocean.
The eruption reached a vast and powerful climax nearly four weeks later, on January 15, 2022.
Can volcanoes erupt into space?
The Tonga volcano blasted winds far into the atmosphere, almost reaching space. In 1979, NASA’s Voyager 1 spacecraft took the first close-up pictures of Io. A massive plume was seen erupting from its surface into space. It was a curiosity that Io had volcanoes — and they were active! This was the first time an erupting volcano had been found anywhere besides on Earth.