The Volcanic Eruption on Tonga
On Saturday, January 15th the small South Pacific island nation of Tonga was hit with a devastating volcanic eruption and ensuing tsunami. The eruption was massive, spewing ash and lava 30 km into the air and causing a giant sonic boom. The sonic boom was heard soon after in nearby Fiji, and hours later as far away as Alaska thousands of miles away. The Hunga Tonga-Hunga Ha’apei volcanic eruption was the largest in the world in 30 years, since the Mount Pinatubo eruption in the Phillipines in 1991.
What were the seismic events that led up to the eruption? According to Professor Shane Cronin of the University of Auckland, this was a once in a millennium event but one that was due. The last major eruption was in 1100 AD, and before that in 200 AD, so the eruption now was almost exactly due. The island had began to have small rumbblings and eruptions back in December 2021 which were foreboding of the big event. As of January 7, the volcanic landmass was above sea level, but by the morning of January 15 (just before the eruption), the island had sunk into the ocean and was ready to explode. The caldera sat 150 to 200 meters below sea level, which was the right depth for there to be quite explosive iteractions between the hot magma and cooler seawater. It was a recipe for disaster that led to the large eruption.
Tonga’s main island, approximately 40 miles south of the volcano, was taken by surprise and not prepared at all. The tsunami from the blast was to the island within minutes, and caused major damage along the shorelines. There was one death with a woman being swept away by the waves. Then came the ash and debris raining down. Within hours, several ash totally covered the northern part of the island. Days later, the island is still a complete disaster zone. Many homes are damaged, the island is largely without internet and connectivity to the world, and flying aid there amid the smoke anda sh has been challenging until the last few days. The most immediate concern has been the contamination of existing water sources and flying fresh water to the island. Needless to say, teh eruption will have a devastating impact on Tonga’s ecosystem and way of life for years to come.
Luckily for the rest of the world, the eruption was not quite big enough to trigger blocking of the sun and affect global temperatures. It is amazing that volcanic eruptions can have the capability to do this, but it is precisely what happened after the massive 1812 eruption of Mount Tambora — global temperatures cooled by several degrees Celsius for a few years. Events like this are eye-opening and show the immense power of forces on Earth, sometimes unfortunately, in this case, to the detriment of countries like Tonga.
