What caused this seven-mile scar in the Australian outback?

What caused the seven-mile scar in the Australian outback seen on Google Earth?

Written by Matej Riper & The Conversation US

The following essay is reproduced with permission. conversationan online publication covering the latest research.

Earlier this year, a cave explorer was poring over satellite images of the Nullarbor Plain when he discovered something unexpected. It was a huge mysterious scar carved into the barren land.

This discovery intrigued scientists, including my colleagues and myself. Upon further investigation, it was determined that the scar was created by a violent tornado that no one knew existed. A summary of the survey results is provided below. new research It was published today.

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Tornadoes are a known threat in the United States and other countries. But they also happens in australia.

Without the power of technology, this amazing example of the power of nature would have gone unnoticed. It’s important to study the aftermath of tornadoes to predict and prepare for the next big twister.

Australian tornado history

tornado A violently rotating column of air falls to the ground from a thunderstorm, with wind speeds often exceeding 200 kilometers per hour. They can cause massive destruction, uprooting trees, tearing buildings apart, and throwing debris long distances.

Tornadoes have been reported on every continent except Antarctica. It most commonly occurs in the Great Plains region of the United States and northeastern regions of India and Bangladesh.

The first tornado observed by Australian settlers occurred outside Sydney in 1795. However, it was not confirmed by Western scientists that tornadoes occurred here until the late 1800s.

Cases documented in Australia in recent decades include: 2013 tornado We crossed northeast Victoria and continued on to the New South Wales border. It brought winds of 250 to 300 kilometers per hour and caused damage to towns on the Murray River.

Then, in 2016, a severe storm occurred, at least 7 tornadoes Located in central and eastern South Australia.

It is important for scientists to accurately predict tornadoes and issue warnings to local communities. That’s why the Nullarbor tornado scar was so useful for research.

swirling mystery

The Nullarbor Plain is a remote, dry, treeless stretch of land in southern Australia. The man who discovered the scar was searching for Nallaver using Google Earth satellite imagery. cave or other karst features.

Karst is a landform characterized by unique topography beneath limestone. The discovery of this scar came to the attention of my colleagues and I through a collaborative network of researchers and explorers studying the Nullarbor karst.

The scars extend from Western Australia across the border to South Australia. It is located 20 km to the north. Trans-Australian Railway It is located 90 kilometers east-northeast of Forrest, a former railroad settlement.

We compared satellite images of the scene over several years and determined that the tornado occurred between November 16 and 18, 2022. A blue circular pattern appeared next to the scar, indicating puddles from heavy rain.

My colleagues and I then visited the site in May of this year to examine and photograph the scar and surrounding landscape.

Our results are as follows published in Southern Hemisphere Earth System Science Journal.

what we found

The scar is 11 kilometers long and 160 to 250 meters wide. You can see an impressive pattern called the “cycloid mark” formed by the tornado’s suction vortex. This suggests that the tornado was not an ordinary storm, but a strong storm. F2 or F3 A category that rotates with destructive winds exceeding 200 kilometers per hour.

The tornado probably lasted between 7 and 13 minutes. The characteristics of the scar suggest that the swirling winds within the tornado were moving clockwise. The tornado also appears to have moved from west to east, which is consistent with the direction of a strong cold front in the area at the time.

Local weather observations also recorded intense cloud cover and rainfall during that period in November 2022.

Unlike tornadoes that hit populated areas, this one did not cause any damage to homes or towns. But it nevertheless left its mark, eroding soil and vegetation and reshaping the Earth’s surface.

Remarkably, the scars were still clearly visible on satellite images and on the ground 18 months after the incident. This is probably because vegetation grows slowly in this arid landscape and has not yet covered the erosion.

anticipate and prepare

This fascinating discovery on the Nullarbor Plains shows how powerful and unpredictable nature can be, sometimes without us even realizing it.

Only three tornadoes have ever been recorded on the Nullarbor Plain. This is likely due to the remoteness of the area with few witnesses and the event causing no damage to property or infrastructure. Interestingly, these three tornadoes occurred in November exactly like this one.

Our study provides valuable insight into tornadoes in this remote and little-studied region. This will help you understand when and under what conditions these types of tornadoes occur.

It also highlights the importance of satellite imagery to identify and analyze weather phenomena in remote areas and help predict and prepare for the next big event.

And finally, this result is a stark reminder that extreme weather events can occur anywhere at any time.

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