Photo credit: phys.org
Earlier this year, an exploration of satellite imagery by a caver led to a surprising discovery on the Nullarbor Plain: a massive, mysterious scar carved into the remote landscape.
This find piqued the interest of scientists, including my colleagues and me. A detailed investigation revealed that the scar was the result of a powerful tornado that had previously gone unnoticed. Our findings are detailed in new research recently published.
While tornadoes are often discussed in the context of the United States, they also occur in Australia, as confirmed by research detailing their presence across the continent. Without technological advancements, this instance of nature’s intensity might have remain hidden, underscoring the necessity of studying tornado remnants for better predictive capabilities regarding future events.
Australia’s Tornado History
Tornadoes are intense columns of air associated with thunderstorms, characterized by wind speeds that can surpass 200 kilometers per hour. They wreak havoc by uprooting trees, dismantling structures, and propelling debris over vast areas.
Every continent except Antarctica has reported tornado occurrences, with the United States’ Great Plains and the India-Bangladesh region being particularly prone to these phenomena.
The first recorded tornado in Australia dates back to 1795 near Sydney, although scientific confirmation of tornadoes came about much later, in the late 1800s.
In recent years, a significant tornado event occurred in 2013 when a tornado crossed northeast Victoria, reaching wind speeds between 250 and 300 kilometers per hour and causing destruction in Murray River townships. A notable series of tornadoes also emerged from a severe storm in 2016 in parts of South Australia.
Effective tornado prediction is crucial for community safety, which makes the Nullarbor tornado scar an important subject for study.
A Whirlwind Mystery
The Nullarbor Plain, a vast and dry region in southern Australia, was where the scar was identified by a man using Google Earth to search for caves and karst formations.
Karst landscapes are characterized by their limestone foundations, resulting in unique geological structures. The scar caught the attention of researchers within a collaborative network studying the Nullarbor’s geological features.
This scar extends from Western Australia into South Australia, located approximately 20 kilometers north of the Trans-Australian Railway and about 90 kilometers east-northeast of the former railway town of Forrest.
Through examining satellite images over time, we were able to ascertain that the tornado occurred sometime between November 16 and 18, 2022. Indicators such as circular patterns adjacent to the scar pointed to significant rainfall following the tornado.
In May of this year, we visited the site to analyze and document the scar and its surroundings firsthand.
Our findings have been published in the Journal of Southern Hemisphere Earth Systems Science.
What We Discovered
The scar measures 11 kilometers in length and spans between 160 and 250 meters in width. It features distinctive “cycloidal marks” created by the tornado’s suction vortexes, indicating that the tornado likely belonged to the strong F2 or F3 categories, with winds exceeding 200 kilometers per hour.
The duration of the tornado is estimated to be between seven and 13 minutes. Analysis suggests the winds were spinning in a clockwise direction, with the tornado moving from west to east, consistent with prevailing weather patterns at that time.
Weather data corroborated the cloud cover and rainfall intensity during the observed period in November 2022.
This tornado, differing from those that strike populated areas, did not inflict damage to homes or infrastructure, but it significantly altered the local landscape, contributing to soil erosion and vegetation loss.
Interestingly, 18 months later, the scar remains clearly visible in satellite images and on the ground, likely because of the slow growth of vegetation in the arid conditions of the Nullarbor.
Preparing for Future Events
This intriguing discovery on the Nullarbor Plain highlights the formidable and sometimes unpredictable forces of nature.
Historically, only three tornadoes have been officially documented in this region, likely due to its remote location and the lack of witnesses, combined with the fact that these events often do not impact human structures. Notably, like the recently discovered tornado, the other three also occurred in November.
Our research offers significant insights into tornado occurrences in this rarely studied area, enhancing our understanding of their conditions and frequency.
This study exemplifies the critical role of satellite imagery in identifying and assessing weather phenomena in remote locations, ultimately aiding in disaster forecasting and preparedness.
Finally, it serves as a crucial reminder that extreme weather can emerge with little warning, posing potential threats no matter where they occur.
More information: Matej Lipar et al, Tornado scar on the Nullarbor Plain, Australia, Journal of Southern Hemisphere Earth Systems Science (2024). DOI: 10.1071/ES24023
Source
phys.org