The Tongan volcano eruption

The Tongan eruption was out of this world

(Quite literally; here's how the eruption is helping us understand Mars)

Satellite imagery shows the Hunga Tonga-Hunga Ha'apai volcano on Jan. 6, 2022, before the eruption on Jan. 14th, 2022 in Hunga Tonga-Hunga Ha'apai Islands, Tonga. Photo credit: Maxar via Getty Images

On January 15th we all spectated from our screens the plumes of ash that engulfed Tonga as a volcanic eruption devastated the unsuspecting archipelago. Half-submerged underwater, the volcano named 'Hunga Tonga-Hunga Ha'apai' has not only changed the lives of 100,000 Tongan citizens, but also the frontiers of Volcanology as we know it. The explosion was calculated to be 500 times the force of the Hiroshima atomic bomb, and for the 11 hours that the eruption lasted, a tsunami was further triggered and reverberations from the eruption circled the globe several times.

These reverberations have further shaken the foundations of volcanology, questioning our true understanding of seismic activity. Imaging says the eruption is one of the largest ever in satellite era, with a diameter of 650km (that's almost the size of Spain!), yet researchers are scratching their heads over the amount of ash emitted, which was much lower than the expected amount for an eruption of this magnitude. While the eruption itself has rendered volcanologists clueless, it could pave the way to certainty beyond Earth when it comes to other planets that also have volcanoes. Prior to the explosion, the volcanic island of Hunga Tonga-Hunga Ha'apai had already attracted the eager eyes of chief scientist James Garvin and his team of researchers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. It is rare to observe the real-time formation of islands, so when an underwater volcano in 2015 began to expel ash and lava, Garvin's team had a front row seat in watching the formation of the island. Unlike most volcanic islands which erode away months after formation, Hunga Tonga Hunga Ha'apai persisted for years, allowing Garvin and his team to analyse its changes using satellite imaging and seafloor surveys. Following its eruption however, the vast majority of the island disappeared, with teams now monitoring the island using optical, radar and laser satellites to measure what is left. This all contributes to a greater understanding of the formation of volcanoes in Mars, which are suspected to have formed in the presence of water. Scientists aren't quite sure if or when volcanoes on Mars erupted, nor what the nature of these eruptions are like, but Hunga Tonga-Hunga Ha'apai reduces this level of speculation. Take the marine environment surrounding Hunga Tonga-Hunga Ha'apai for example, which also mirrors the low-gravity settings found on Mars and thus “ can shed unique light on Martian features that formed in lower gravity" , according to planetary scientist Joseph Michalski at the University of Hong Kong.

500times the force of the Hiroshima atomic bomb

Lily Pfaffenzeller