Researchers Pinpoint Cause of Strange Scar in Australian Outback

A strange set of marks in the Australian outback is actually the footprint of a huge twister that went unnoticed until now, according to a team that recently reviewed satellite imagery of the marks.

Twisters, or tornadoes, or vehicles by which girls from Kansas get transported to the magical land of Oz—whatever you call them—are narrow, rapidly rotating columns of air that can cause devastating damage on the ground. Tornadoes are especially common in the central United States’ Tornado Alley, but have been reported on every continent but Antarctica. The recent finding is a cycloidal twist in the tale of the Western Australia-South Australia border, where twisters are not common, and showcases the extreme weather that happens on our planet—even when no one is around to see it.

The twister occurred sometime between November 16, 2022 and November 18, 2022, based on available satellite imagery. The marks suggest the weather event was 6.84 miles longer (11 kilometers) and up to 820 feet (250 meters) wide, with wind speeds exceeding 124 miles per hour (200 km/hr). The team’s research describing the weather event was published last week in the Journal of Southern Hemisphere Earth Systems Science.

Cycloidal marks scarring the Australian outback. Image: Google Earth

“It bears striking patterns called ‘cycloidal marks,’ formed by tornado suction vortexes,” said Matej Lipar, a researcher at Curtin University in Australia and lead author of the study, in The Conversation. “This suggests the tornado was no ordinary storm but in the strong F2 or F3 category, spinning with destructive winds.”

Tornadoes drop down to the ground from thunderclouds. They’ve been reported in every U.S. state but are more common in the Great Plains, where the winds often favor tornado formation, but the region only becomes warm and humid enough for thunderstorms in the spring. That’s why Hurricane Milton’s tornadoes caught many off guard when the  Category 3 storm touched down in Florida last month; Florida is not generally known for tornadoes, but the hurricane brought choice conditions for the twisters to form. The hurricane ultimately caused at least three dozen tornadoes due to a perfect storm of factors.

The 2022 Nullarbor Plain tornado was unusual compared to other tornadoes in southern Australia. Most tornado events in the area between 1795 and 2014 occurred south of Perth—Australia’s southwestern tip—and west of Adelaide, to the east. The recently investigated tornado happened between the two, about 12.4 miles (20 km) north of the Trans-Australian Railway.

Because the area is so sparsely vegetated, the scars caused by the twister were still visible in satellite images and on the ground in spring 2023, some 18 months after the event. The team believes the twister swirled clockwise in an eastward direction for 7 to 13 minutes, and moved consistently with a cold front that swept through the region at the time.

The event was not previously recorded because it occurred in an uninhabited area, and so didn’t cause damage to any buildings. But finding out about such a violent event in hindsight is its own kind of eerie, and a reminder of the intensity of Earth’s weather even absent a human presence.