Tonga volcano eruption disrupted satellites halfway around the world

A massive volcanic eruption in Tonga last year was so powerful that it disrupted a moon on the other side of the globe. Researchers warn that similar phenomena could again cause dangerous interference in the future unless we learn how to predict seismic activity more accurately.

The January 2022 eruption of Hunga Tonga Hunga Ha’apai volcano was the most explosive of the 21st century, creating a tsunami 90 meters high and sending ash up to 57 kilometers into the sky. Atsuki Shinbori of Nagoya University and others now reveal that it also disrupted satellite communications thousands of miles away.

GPS satellites have long been known to be vulnerable to an effect called the equatorial plasma bubble (EPB). These are areas of low pressure that bubble up and rise through the atmosphere. During the day, the sun’s rays ionize the highest part of the atmosphere, a layer called the F region, located 150 to 800 kilometers above the Earth’s surface. This increases the density of the ionosphere due to the strength of the sun. At the equator it increases even more than elsewhere.

At night, these ions recombine to form EPBs, which can affect the transmission of radio waves in the atmosphere that carry GPS signals. Scientists have previously discovered that EPBs can also be formed by wind, and researchers have long theorized that EPBs are also formed by volcanic activity.

“Previously, it was not possible to clearly connect them. Now, with the spread of the Internet, a wide variety of observational data has become available, making integrated data analysis possible,” says Shinbori. .

Scientists noticed deterioration in GPS signals during Tonga’s eruption. Shinbori and his colleagues are now analyzing the data to prove the correlation. They used data from the Arase satellite, which detects EPB, the Himawari-8 satellite, which monitors pressure waves, and ground-based ionospheric observations. They found evidence of EPB in low-latitude regions from near the equator in Asia after the arrival of pressure waves generated by volcanic eruptions. Shinbori says more accurate predictions of volcanic activity are essential to mitigating the effects of satellite destruction.