Hunga Tonga-Hunga Ha'apai Erupts

A powerful volcanic eruption has obliterated a small, uninhabited South Pacific island known as Hunga Tonga-Hunga Ha'apai. Damage assessments are still ongoing, but preliminary reports indicate that some communities in the island nation of Tonga have been severely damaged by volcanic ash and significant tsunami waves.

The volcano had sporadically erupted multiple times since 2009. The most recent activity began in late December 2021 as a series of Surtseyan eruptions built up and reshaped the island, while sending bursts of tephra and volcanic gases spewing from the vent. Relatively powerful blasts shook Hunga Tonga-Hunga Ha'apai on January 13, but it was an even more intense series of explosions early on January 15 that generated atmospheric shock waves, sonic booms, and tsunami waves that traveled the world.

Several Earth-observing satellites collected data during and after the eruption. Scientists affiliated with NASA's Disasters program are now gathering imagery and data, and they are sharing it with colleagues around the world, including disaster response agencies.

The sheer power of the eruption was quickly apparent in satellite imagery. As shown in the animation above, a vast plume of material created what volcanologists call an umbrella cloud with crescent-shaped bow shock waves and a vast number of lightning strikes.

"The umbrella cloud was about 500 kilometers (300 miles) in diameter at its maximum extent," said Michigan Tech volcanologist Simon Carn. "That is comparable to Pinatubo and one of the largest of the satellite era. However, the involvement of water in the Tonga eruption may have increased the explosivity compared to a purely magmatic eruption like Pinatubo."

NOAA's Geostationary Operational Environmental Satellite 17 (GOES-17) captured the images for the animation above. The natural-color views from the satellite's Advanced Baseline Imager were acquired between 5 and 8 p.m. local time (04:00 to 07:00 Universal Time) as the volcanic plume expanded upward and outward over the South Pacific. (NASA builds and launches the GOES series of satellites for NOAA.)