Underwater Researchers Uncover Mysteries in the World’s Largest Underwater Volcano

However, in 2022, that island was obliterated in the largest volcanic eruption in recorded history. So, what exactly are we hoping to learn from this seismic event? 

The appearance of this new island offered a unique opportunity to learn more about how complex organisms eventually colonize islands. However, the island didn’t last for long since it was destroyed by a different eruption in January 2022. 

In a recent study, researchers reported evidence of a surprising microbe community in Hunga Tonga-Hunga Ha-Pai. These organisms had the ability to metabolize atmospheric gases and sulfur, much like the organisms living in deep-sea hydrothermal vents and hot springs.

They had assumed they would find cyanobacteria or organisms similar to those on glacier retreats. Essentially, they thought they’d find colonizing species. However, they stumbled upon a unique bacterial group that metabolizes atmospheric gases and sulfur.

Quickly after the island’s formation, plants colonized it. The team believes it was likely from seeds in bird droppings.

They did note, however, that the microbes found in the volcano’s cone provided far less diversity versus the microbes from the vegetated ground. They were also very different organisms altogether. 

Instead, they believed that the bacteria came from far beneath the surface of the Earth. Their beliefs stemmed from the fact that the hydrogen sulfide gas was the thing fueling the unique organisms they had discovered.

Though they had seen organisms like this before, it was rare having the opportunity to investigate this type of system. It was forming from a blank slate or new organic matter. 

Many scientists flocked to those islands to study life there, though they mainly focused on plants and animals rather than studying microbes. 

However, the main difference is that these volcanic eruptions do not usually form islands. The team was presented with what may have been a once-in-a-lifetime opportunity to study microorganisms on this scale at the earliest stages of an island’s formation. For the team, it was a dream come true.

Surprisingly enough, this volcano produced what would be the largest eruption in the 21st century. It also took the world record for the highest plume of ash and steam ever. Luckily, scientists learned from the island before it was obliterated. 

It was so strong that people in Alaska could hear it, even from over 6,000 miles away. The tsunami that ensued created 15-meter waves and did an estimated $90.4 million in damages in Tonga.

What puzzled them was that only ¾ of the material from the blast was deposited 12 miles surrounding the volcano, with much of it missing.

Essentially, the material shot upward into the atmosphere, where it remained, circulating for many months. 

The research vessel was set to sail in April 2022 to discover more about the unusually violent eruption. At this point, the once large island was split into two smaller islands — Hunga Tonga and Hunga Ha’apai.

Erica is a self-described “seafloor detective,” using cutting-edge echolocation technology to find underwater volcanoes and learn more about what influences act as catalysts for these massive underwater eruptions. 

With it, Erica wanted to procure rock samples and mud sediment from the seafloor and operate the multibeam echosounder to map the seafloor using acoustic pulses. She likened the technology to dolphin echolocation, allowing them to build geometry and space based on readings.

Before the massive eruption, the island didn’t give scientists much to look at. However, beneath the water’s surface, the volcano stretched over two kilometers deep and 20 kilometers wide, painting a much larger portrait of discovery possibilities.

However, a decent portion of the volcanic material was shot straight up into the stratosphere, leaving the volcano looking much like it did before the eruption. 

The volcano’s hot magma was mixed with the cold ocean water, creating steam. Compared to water, steams take up about a thousand times more volume. This gave the team a clue as to why the volcano was so incredibly eruptive.

Localized waves were a result of the initial blast, though air pressure changes created a meteotsunami that traveled faster than the speed of sound. This pressure wave likely traveled across the globe anywhere from three to four times over.

Now, with the new data gathered from the Tonga region, the team can better refine their sensor technology. 

She also noted that this was the first time she measured the data from an event using modern instrumentation.

A new global initiative from the Nippon Foundation, Seabed 2030, aims to use these findings to map the entirety of the ocean floor. 

They can also help in the recovery of the surrounding marine ecosystem. 

Erica Spain says that by mapping, observing, and understanding our ocean, we can better understand how we impact it.