During Tonga’s Hunga Volcano eruption on January 15, 2022, a staggering 200,000 lightning flashes, illustrated as blue dots, were observed. Recent studies into the intensity of the eruption-induced lightning reveal it was the most potent ever documented, shedding new light on the eruption’s evolution. The study was conducted by Van Eaton et al. (2023) and published in the Geophysical Research Letters.
At the height of the eruption, a record-breaking 2,600 lightning flashes were produced per minute. The lightning also served as a tool for scientists to explore the ash cloud, revealing new details about the eruption’s timeline.
The eruption lasted for approximately 11 hours, exceeding previous estimations by several hours. Remarkably, the volcanic plume generated the highest-altitude lightning flashes ever measured, reaching 20 to 30 kilometers (12 to 19 miles) above sea level. The lightning also exhibited a unique “surfing” behavior across the colossal waves within the volcanic plume.
On January 15, 2022, the Hunga Volcano’s eruption in Tonga set new records. The research indicates that the eruption spawned a hyper-intense thunderstorm, leading to the most intense recorded lightning. This thunderstorm produced nearly 200,000 lightning flashes within the volcanic plume over the eruption’s duration, peaking at over 2,600 flashes per minute.
The underwater volcano’s eruption in the southern Pacific Ocean created a plume of ash, water, and magmatic gas rising to at least 58 kilometers (36 miles) high. While providing valuable information about the eruption’s magnitude, the plume also obscured the vent from satellite view, complicating the tracking of the eruption’s progression.
High-resolution lightning data from four separate sources were combined to peer into the plume, revealing new phases of the eruption’s life cycle and the unusual weather patterns it produced.
Alexa Van Eaton, a volcanologist at the United States Geological Survey and the study’s lead, commented, “This eruption initiated a hyper-intense thunderstorm unlike any we’ve ever seen.” These results underscore a novel method for real-time volcano monitoring, improving ash hazard advisories for aviation.
The eruption’s unique storm formation was a result of highly energetic magma blasting through the shallow ocean, according to Van Eaton. The molten rock vaporized the seawater, which rose into the plume, leading to electrifying collisions between volcanic ash, supercooled water, and hailstones, creating ideal conditions for lightning.
By combining data from light and radio wave sensors, the researchers were able to track the lightning flashes and estimate their heights. The eruption generated just over 192,000 flashes, with some reaching extraordinary altitudes of 20 to 30 kilometers (12 to 19 miles) high.
Van Eaton stated that these findings not only clarified the eruption’s duration but also revealed its temporal behavior. The lightning data was instrumental in determining the eruption’s phases and the previously unknown 11-hour activity duration.
The research indicates that integrating lightning intensity with eruptive activity can lead to enhanced monitoring and nowcasting of aviation hazards during significant volcanic eruptions. This is particularly vital for remote, submarine volcanoes where obtaining reliable initial information about volcanic plumes is challenging. Utilizing all long-range observations, including lightning, can improve early detection and mitigate potential hazards.
Van Eaton and her colleagues were intrigued by the formation of concentric lightning rings centered on the volcano, which expanded and contracted over time. “The scale of these lightning rings was mind-boggling. We’ve never seen anything like it before; there’s nothing comparable in meteorological storms,” she said.
The researchers attributed the formation of these rings to intense, high-altitude turbulence. The plume injected a substantial mass into the upper atmosphere, creating ripples in the volcanic cloud akin to pebbles dropped in a pond. The lightning appeared to ‘ride’ these waves, forming 250-kilometer-wide rings.
Adding to the eruption’s intrigue, it represents a type of volcanism known as phreatoplinian, which occurs when a large volume of magma erupts through water. This eruption style was previously only known from the geological record and had never been observed with modern instruments. The Hunga eruption changed this status quo.
Van Eaton likened the observation of this eruption style to “unearthing a dinosaur and seeing it walk around on four legs. It’s quite breathtaking.”
The referenced study, titled “Lightning Rings and Gravity Waves: Insights Into the Giant Eruption Plume From Tonga’s Hunga Volcano on 15 January 2022” was conducted by Alexa R. Van Eaton, Jeff Lapierre, Sonja A. Behnke, Chris Vagasky, Christopher J. Schultz, Michael Pavolonis, Kristopher Bedka, and Konstantin Khlopenkov, and was published in Geophysical Research Letters on June 20, 2023.
Frequently Asked Questions (FAQs) about volcanic lightning
What was the significance of the lightning activity during Tonga’s Hunga Volcano eruption?
The lightning activity during Tonga’s Hunga Volcano eruption was significant because it was the most intense ever recorded, providing new insights into the eruption’s progression. It allowed scientists to monitor the volcanic plume, understand the duration of the eruption, and track its behavior over time. The lightning data also revealed previously unknown phases of the eruption, aiding future volcanic hazard monitoring.
More about volcanic lightning
- Geophysical Research Letters: Link to the study
- Tonga’s Hunga Volcano Eruption: News article
- United States Geological Survey: Official website
- Lightning Phenomena: Wikipedia article