Tonga volcanic eruption highlights crucial role of satellites in crises

Before and after satellite images of the city of Nuku’alofa, Tonga captured by Maxar Technologies. The city covered in ash after the eruption. Maxar Technologies

Significant damage was reported in Tonga this week, days after a massive nearby volcano violently erupted, triggering earthquakes, a tsunami and a massive ash cloud that blanketed the entire Pacific island nation.

The Hunga Tonga Hunga Ha’apai volcano, located just 40 miles north of Tonga’s capital, Nuku’alofa, erupted on Saturday evening. It is the largest volcanic eruption recorded on Earth in over 30 years.

Communication was completely cut off in the first hours after the eruption as the only fiber optic undersea cable that connects Tonga to the rest of the world was severed during the disaster. A second submarine cable that connects the islands of Tonga was also damaged, the Associated Press later reported.

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So far during the crisis, satellites, which sit safely above the Earth’s atmosphere, have been a crucial, and sometimes the only, tool for the outside world to get a glimpse of the latest in Tonga, a country of about 106,000 people.

The first clear view of the dramatic eruption was captured by Japan’s Himawari 8 weather satellite. Images showed a plume of ash, steam and gas spewing up to 13 miles into the atmosphere like a giant mushroom above of the South Pacific.

San Francisco-based Earth imaging company Planet Labs PBC had been monitoring the Hunga Tonga Hunga Ha’apai volcano since late December after a smaller vent erupted. The December eruption increased the volcano’s above sea surface by almost 45% due to ashfall, dramatically changing its appearance in just a few days. Scientists believed the volcano was calming down, Planet Labs said in a blog post days before the Jan. 15 eruption.

Other satellite images of Tonga released Monday and Tuesday, including those captured by Planet Labs and Colorado-based Maxar Technologies, showed the stark difference before and after the eruption. Maxar’s images from Nuku’alofa showed the capital covered in thick volcanic ash and smog after the eruption and houses and public facilities damaged by the tsunami.

The only people in Tonga who have managed to contact the outside world are those who have access to satellite phones, although the connection is unstable due to the thick ash cloud blocking signals from time to time, according to the President of Tonga Cable Ltd., Samuela Fonua. .

Natural disaster experts point out that the crisis highlights just how vulnerable cable-dependent telecommunications infrastructure is for remote countries like Tonga.

“Events in Tonga underscore once again just how fragile the global network of submarine cables is and how quickly it can disconnect,” wrote Dale Dominey-Howes, professor of hazard and disaster risk sciences. at the University of Sydney, in an article for United. Press International published on Tuesday.

“Cables cluster in narrow corridors and pass between so-called ‘critical choke points’ such as the Hawaiian Islands, the Suez Canal and Guam, Dominey-Howes explained, “making them vulnerable to a number of natural hazards, including volcanic eruptions, underwater landslides, earthquakes and tsunamis.

Tonga is particularly vulnerable to this type of disruption as there is only one cable connecting the country to Fiji, located approximately 500 miles away.

“This is not the first time a natural disaster has severed critical undersea cables, and it won’t be the last,” Dominey-Howes warned. “Governments and telecommunications companies should find ways to diversify the way we communicate, for example by using more satellite systems and other technologies.”

Tonga volcanic eruption highlights crucial role of satellites in natural disasters


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