By: Chloe Wu
On January 15, 2020, an underwater volcanic eruption in the South Pacific region of Tonga amazed scientists with its power. The eruption propelled dust and ash beyond the stratosphere, the second highest layer of the atmosphere. It also initiated a tsunami that was as tall as the Statue of Liberty. Recently, scientists have recorded lightning strikes at the highest altitudes in history caused by the eruption from a year ago.
Lightning flashes caused by the eruption plumes were recorded to be 20 to 30 kilometers up in the sky, thus occurring in the stratosphere. Most lightning flashes occur in the troposphere, which is 12 to 18 kilometers high in the sky. At its peak, the storm can produce 2600 lightning flashes per minute.
Alexa Van Eaton, a volcanologist at the U.S. Geological Survey led a team to observe and collect data about the altitudes of the lighting strikes. Eaton states, “We’ve never seen anything like this sheer rate of lightning before—and at such high altitudes.” (Smithsonian)
Eaton’s team collected different types of data about the lightning strikes. They were able to collect data about the radio waves created by the lightning. Their data revealed that the lightning strikes formed 20 kilometers above sea level, which is higher than normal. Starting up that high causes the air pressure to form channels of hot plasma in the lightning, revealing that the lightning strikes were caused by the eruption.
Sam Purkis, a geologist at the University of Miami states, “This is a fascinating study and shows how the Tongan eruption influenced the Earth system in ways that you might not immediately associate with a volcanic explosion.” (Smithsonian)
The volcano, located near the islands of Hungo Tonga and Hunga Ha’apai, has been active since December 19, 2021. However, its activity peaked on January 15, 2022. The tsunami caused following the eruption killed six people in total – four in Tonga and two in Peru. The eruption affected 80% of Tonga’s population.
As more data is collected from the lightning strikes, scientists are working hard to analyze their observations of this awe-inspiring phenomenon. The aftermath of the underwater volcanic eruption made history and serves as a powerful reminder of our dynamic planet.