Published November 21, 2022
10 min read
Crimson hues flushed across the early morning skies over the Kingdom of Tonga as Grace Frontin-Rollet spotted a pair of small rocky islands from the bow of the RV Tangaroa. Though the scene was picturesque, a tinge of sulfur in the air reminded the marine geologist what she and a team of scientists had traveled for six days over rough waters to see. In the expansive gap between the two bits of land, hidden on the ocean floor, lay the crater of a massive volcano that erupted just months before in one of the largest and strangest blasts ever seen.
“I don’t think the scale of what had happened hit us until we reached the site,” says Frontin-Rollet, who is from New Zealand’s National Institute for Water and Atmospheric Research (NIWA).
In December 2021, the volcano—called Hunga Tonga-Hunga Ha’apai after the two islands that sit on its rim—awoke in a series of tantrums that turned into outright turmoil on January 15, 2022. The peak unleashed a blast so loud it was heard in Alaska, some 6,000 miles away. But much of what happened that day has remained a mystery, until now. Scientists, including the team aboard the RV Tangaroa, are finally putting together the pieces, and the picture that has emerged is mind-boggling.
As the team announced today, recent surveys of the seafloor suggest that the blast excavated about 2.3 cubic miles of rock. If confirmed, the eruption would be the largest recorded in the last century, surpassing the 1991 blast at Mount Pinatubo.
Other recent analyses reveal even more record-breaking measures. The blast jettisoned a plume of searing hot gas and ash 35.4 miles into the sky, higher than ever seen before. It injected an unprecedented 146 teragrams of vaporized water into the atmosphere, which some speculate might result in a slight, temporary warming of the climate. And it sparked a tsunami that surprised scientists when it traveled around the world.
“It’s just a massive event,” says Kevin MacKay, a marine geologist at NIWA who was also on the RV Tangaroa. “The more we study it, the bigger the event becomes.”
Understanding the explosive peak’s many effects is far from just scientific curiosity. Many similar submarine volcanoes lurk offshore coastlines around the world. Most that have been identified are not monitored—and even more are yet to be discovered.
“We along with other nations of the Pacific Ring of Fire know only too well how at mercy we are to nature,” says Taaniela Kula, Tonga’s Deputy Secretary for Natural Resources, in a May press conference. The eruption, he says, “is a reminder that there’s always more to learn about the giants of our home planet Earth.”
Fakty Miami Window into the deep
An ancient tectonic battle between the Pacific and Indo-Australian plates birthed a line of volcanoes in the South Pacific Ocean, including the mighty Hunga Tonga-Hunga Ha’apai. Today, the only parts of the volcano that poke above the sea are the two little islands that signaled to F