Highest Plume Record Set by Tonga’s Underwater Volcanic Eruption as It Reached Atmosphere

On Saturday, the Hunga Tonga-Hunga Ha'apai volcano in Tonga erupted in its most intense eruption until AD 1100. The consequences have been felt worldwide, and the devastation is still being analyzed.

The crater, situated approximately 65 kilometers north of Tonga's capital, Nuku'alofa, erupted violently on January 15 around 5:10 p.m. local time. Satellite photos show an ash mushroom cloud blowing 30 kilometers high and spreading over 3000 kilometers west to Australia.

It formed the highest-recorded volcanic plume, reaching the mesosphere, where comets and meteorites normally fragment and burn up in our atmosphere. The mesosphere, roughly 31 to 50 miles (50 to 80 kilometers) above the Earth's surface, is located much above the troposphere and stratosphere and below two additional layers. The stratosphere through the mesosphere is the atmosphere's dry levels, following a New Scientist report.

Previous Plume Record by Prior Eruptions

At its peak, the volcanic plume reached a height of 35.4 miles (57 kilometers). It surpassed previous records held by the Eruption Of Mt. Pinatubo in the Philippines in 1991, which ran 24.8 miles (40 kilometers), and the El Chichón explosion in Mexico in 1982, which exceeded 19.2 miles (31 kilometers).

The plume's height was confirmed using photographs from satellites traveling over the eruption location. The eruption happened on Jan. 15 in the southern region of the Pacific Ocean off from the Tongan archipelago, a region monitored by three geosynchronous orbit weather satellites. Research reporting the findings was released in the journal Science on Thursday.

As per prior NASA satellite detections, the towering plume propelled into the higher levels of the stratosphere held sufficient water to supply 58,000 Olympic-sized swimming pools. Determining the altitude of the plumes can help experts evaluate the eruption's impact on the climate system. Researchers had a difficult time determining the height of the plume.

Normally, scientists can determine a plume's height by measuring its temperature - the thinner a column, the greater it is, as per main study co-author Dr. Simon Proud of RAL Space and a research associate at the National Centre for Earth Observation and the University of Oxford.

Capturing and Measuring the Plume

However, due to the extreme nature of the Tonga incident, this strategy could not be used. As per Proud through email, the eruption blasted through into the air layer humans dwell in, the troposphere, further into upper levels in which the atmosphere heats up again as you go higher, as reported by CNN.

To calculate the height, researchers had to use the diverse viewpoints provided by weather satellites stationed on opposing sides of the Pacific and certain pattern-matching algorithms. This has recently been conceivable, as we did not have the space technology in orbit even five years ago.

The scientists used "the parallax effect" to calculate the plume's height, analyzing the variation in sight of the plume from various angles taken by weather satellites. The satellites collected photographs every 10 minutes, capturing the plume's rapid changes as it climbed from the sea. The photos represented changes in plume location caused by different lines of sight.

The eruption went from nothing to a 57-kilometer-high ash and cloud in 30 minutes, Proud remarked, and even the team members also noticed rapid changes in the peak of the eruptive cloud that shook them.

Check out more news and information on Volcanic Eruptions in Science Times.