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A man scouring Google Earth found a mysterious scar in the Australian outback – and now scientists know what caused it

<div class="theconversation-article-body"> <p>By <a href="https://theconversation.com/profiles/matej-lipar-1372667">Matej Lipar</a>, <em><a href="https://theconversation.com/institutions/curtin-university-873">Curtin University</a></em></p> <p>Earlier this year, a caver was poring over satellite images of the Nullarbor Plain when he came across something unexpected: an enormous, mysterious scar etched into the barren landscape.</p> <p>The find intrigued scientists, including my colleagues and I. Upon closer investigation, we realised the scar was created by a ferocious tornado that no-one knew had occurred. We outline the findings in <a href="https://doi.org/10.1071/ES24023">new research</a> published today.</p> <p>Tornadoes are a known threat in the United States and elsewhere. But they also <a href="https://doi.org/10.1016/j.atmosres.2016.03.011">happen in Australia</a>.</p> <p>Without the power of technology, this remarkable example of nature’s ferocity would have gone unnoticed. It’s important to study the tornado’s aftermath to help us predict and prepare for the next big twister.</p> <h2>Australia’s tornado history</h2> <p><a href="https://doi.org/10.1007/978-3-642-05381-8">Tornadoes</a> are violent, spinning columns of air that drop from thunderstorms to the ground, bringing wind speeds often exceeding 200 kilometres an hour. They can cause massive destruction – uprooting trees, tearing apart buildings and throwing debris over large distances.</p> <p>Tornadoes have been reported on every continent except Antarctica. They most commonly occur in the Great Plains region of the United States, and in the north-east region of India–Bangladesh.</p> <p>The earliest tornado observed by settlers in Australia occurred in 1795 in the suburbs of Sydney. But a tornado was not confirmed here by Western scientists until the late 1800s.</p> <p>In recent decades, documented instances in Australia include a <a href="https://knowledge.aidr.org.au/resources/tornado-murray-river-townships-victoria-2013/#:%7E:text=Tornado%20%2D%20Murray%20River%20townships%2C%202013&text=At%20approximately%208.00pm%20on,border%20of%20New%20South%20Wales.">2013 tornado</a> that crossed north-east Victoria and travelled up to the New South Wales border. It brought winds between 250–300 kilometres an hour and damaged Murray River townships.</p> <p>And in 2016, a severe storm produced <a href="https://theconversation.com/severe-thunderstorms-are-sweeping-through-southern-australia-but-what-makes-a-thunderstorm-severe-241555#:%7E:text=In%202016%2C%20huge%20rotating%20supercell,after%20taking%20down%20six%20towers.">at least seven tornadoes</a> in central and eastern parts of South Australia.</p> <p>It’s important for scientists to accurately predict tornadoes, so we can issue warnings to communities. That’s why the Nullarbor tornado scar was useful to study.</p> <h2>A whirlwind mystery</h2> <p>The Nullarbor Plain is a remote, dry, treeless stretch of land in southern Australia. The man who discovered the scar had been using Google Earth satellite imagery to search the Nullabor for <a href="https://doi.org/10.1007/978-3-031-24267-0_11">caves</a> or other karst features.</p> <p>Karst is a landscape underlain by limestone featuring distinctive landforms. The discovery of the scar came to the attention of my colleagues and I through the collaborative network of researchers and explorers who study the Nullarbor karst.</p> <p>The scar stretches from Western Australia over the border to South Australia. It lies 20 kilometres north of the <a href="https://www.nma.gov.au/defining-moments/resources/trans-australian-railway">Trans-Australian Railway</a> and 90 kilometres east-north-east of Forrest, a former railway settlement.</p> <p>We compared satellite imagery of the site over several years to determine that the tornado occurred between November 16 and 18, 2022. Blue circular patterns appeared alongside the scar, indicating pools of water associated with heavy rain.</p> <p>My colleagues and I then travelled to the site in May this year to examine and photograph the scar and the neighbouring landscape.</p> <p>Our results have been <a href="https://doi.org/10.1071/ES24023">published today</a> in the Journal of Southern Hemisphere Earth Systems Science.</p> <figure class="align-center "><img src="https://images.theconversation.com/files/633465/original/file-20241121-17-bx4uhg.png?ixlib=rb-4.1.0&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/633465/original/file-20241121-17-bx4uhg.png?ixlib=rb-4.1.0&q=45&auto=format&w=600&h=315&fit=crop&dpr=1 600w, https://images.theconversation.com/files/633465/original/file-20241121-17-bx4uhg.png?ixlib=rb-4.1.0&q=30&auto=format&w=600&h=315&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/633465/original/file-20241121-17-bx4uhg.png?ixlib=rb-4.1.0&q=15&auto=format&w=600&h=315&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/633465/original/file-20241121-17-bx4uhg.png?ixlib=rb-4.1.0&q=45&auto=format&w=754&h=395&fit=crop&dpr=1 754w, https://images.theconversation.com/files/633465/original/file-20241121-17-bx4uhg.png?ixlib=rb-4.1.0&q=30&auto=format&w=754&h=395&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/633465/original/file-20241121-17-bx4uhg.png?ixlib=rb-4.1.0&q=15&auto=format&w=754&h=395&fit=crop&dpr=3 2262w" alt="map of Australia's southwest coast with dots showing recorded tornadoes" /><figcaption><span class="caption">Map showing tornado events in Western Australia and South Australia between 1795 and 2014. The location of the tornado scar in the study is shown with a red dot.</span> <span class="attribution"><span class="source">Source: Severe Thunderstorm Archive/Australian Bureau of Meteorology</span></span></figcaption></figure> <h2>What we found</h2> <p>The scar is 11 kilometres long and between 160 and 250 metres wide. It bears striking patterns called “cycloidal marks”, formed by tornado suction vortexes. This suggests the tornado was no ordinary storm but in the strong <a href="https://ntrs.nasa.gov/citations/19720008829">F2 or F3</a> category, spinning with destructive winds of more than 200 kilometres an hour.</p> <p>The tornado probably lasted between seven and 13 minutes. Features of the scar suggest the whirling wind within the tornado was moving in a clockwise direction. We also think the tornado moved from west to east – which is consistent with the direction of a strong cold front in the region at the time.</p> <figure class="align-center "><img src="https://images.theconversation.com/files/622894/original/file-20241002-20-xzi4qn.jpg?ixlib=rb-4.1.0&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/622894/original/file-20241002-20-xzi4qn.jpg?ixlib=rb-4.1.0&q=45&auto=format&w=600&h=340&fit=crop&dpr=1 600w, https://images.theconversation.com/files/622894/original/file-20241002-20-xzi4qn.jpg?ixlib=rb-4.1.0&q=30&auto=format&w=600&h=340&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/622894/original/file-20241002-20-xzi4qn.jpg?ixlib=rb-4.1.0&q=15&auto=format&w=600&h=340&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/622894/original/file-20241002-20-xzi4qn.jpg?ixlib=rb-4.1.0&q=45&auto=format&w=754&h=428&fit=crop&dpr=1 754w, https://images.theconversation.com/files/622894/original/file-20241002-20-xzi4qn.jpg?ixlib=rb-4.1.0&q=30&auto=format&w=754&h=428&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/622894/original/file-20241002-20-xzi4qn.jpg?ixlib=rb-4.1.0&q=15&auto=format&w=754&h=428&fit=crop&dpr=3 2262w" alt="spiralling masks in dry earth" /><figcaption><span class="caption">‘Cycloidal marks’ in the tornado scar, caused by multiple vortexes.</span> <span class="attribution"><span class="source">Google Earth satellite imagery</span></span></figcaption></figure> <p>Local weather observations also recorded intensive cloud cover and rainfall during that period in November 2022.</p> <p>Unlike tornadoes that hit populated areas, this one did not damage homes or towns. But it left its mark nonetheless, eroding soil and vegetation and reshaping the Earth’s surface.</p> <p>Remarkably, the scar was still clearly visible 18 months after the event, both in satellite images and on the ground. This is probably because vegetation grows slowly in this dry landscape, so hadn’t yet covered the erosion.</p> <h2>Predict and prepare</h2> <p>This fascinating discovery on the Nullarbor Plain shows how powerful and unpredictable nature can be – sometimes without us knowing.</p> <p>Only three tornadoes have previously been documented on the Nullarbor Plain. This is likely because the area is remote with few eye-witnesses, and because the events do not damage properties and infrastructure. Interestingly, those three tornadoes occurred in November, just like this one.</p> <p>Our research provides valuable insights into the tornadoes in this remote and little-studied region. It helps us understand when, and in what conditions, these types of tornadoes occur.</p> <p>It also emphasises the importance of satellite imagery in identifying and analysing weather phenomena in remote locations, and in helping us predict and prepare for the next big event.</p> <p>And finally, the results are a stark reminder that extreme weather can strike anywhere, anytime.</p> <hr /> <p><em>Hero Image: Author supplied/Google Earth</em></p> <p><em>This article has been amended to clarify that a reference to early tornado observations relates only to the period after British colonisation.</em><!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/239867/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> <p><em><a href="https://theconversation.com/profiles/matej-lipar-1372667">Matej Lipar</a>, Adjunct Research Fellow, School of Earth and Planetary Sciences, <a href="https://theconversation.com/institutions/curtin-university-873">Curtin University</a></em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/a-man-scouring-google-earth-found-a-mysterious-scar-in-the-australian-outback-and-now-scientists-know-what-caused-it-239867">original article</a>.</em></p> </div>

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On board the Indian Pacific: The magic of the Nullarbor

<p><strong><em>Justine Tyerman continues her journey on the famous trans-continental Indian Pacific train from Perth to Sydney. On Day 2 of her epic 4352km, three-night, four-day trip from the Indian Ocean to the Pacific Ocean, she hears and sees ghosts… </em></strong></p> <p>When hostess Nikki knocked on my cabin door at 5.40am on Day 2 of my Indian Pacific train journey across Australia, I seriously regretted agreeing to such an early call on a chilly winter morning. But then I squinted through a slit in the venetian blinds and witnessed a magical sight - dawn on the Nullarbor Plain. Suddenly wide awake, I leapt from my cosy bed, pulled on every merino and down thing I could find in my case, and bolted down the corridor, hooking my camera strap on the cabin door handle in my haste and almost decapitating myself.</p> <p>The train had stopped at the Outback settlement of Rawlinna for a sunrise breakfast and the early birds among my fellow passengers were already outside, huddled around a series of open fires burning brightly in half drums. Our onboard entertainer Mattie was playing a lively rendition of the Indian Pacific theme song:</p> <p><em>From the waters of the western sea to the eastern ocean sand, the Indian Pacific spans the land…</em></p> <p>and Nikki was carrying huge trays of delicious bacon and egg sliders, vegemite pinwheels and hot drinks around the hungry masses. I’ve never seen food consumed with such speed and gusto.</p> <p style="text-align: center;"><img style="width: 500px; height:281.25px;" src="https://oversixtydev.blob.core.windows.net/media/7820118/image_.jpg?width=500&amp;height=281.25" alt="" data-udi="umb://media/078cc2a215f044289e1e87ec913e52f1" /></p> <p style="text-align: center;">Caption: <em>A farm house belonging to Rawlinna Station, Australia's largest sheep station.</em></p> <p>Rawlinna is home to the largest sheep station in Australia - the 2.5m-acre Rawlinna Station, established in 1962, runs 70,000 sheep. It’s a popular disembarkation spot for jackaroos and jillaroos, young novices looking for experience on Outback farms.</p> <p>With a slider and pinwheel in hand, I took the opportunity to get some much-needed exercise and walked to the tail end of the Indian Pacific, 700 metres away, talking photos of the sunrise from every angle I could think of - including under the train and between the wheels. I’d love to have been an eagle, like the emblem on the carriages, soaring high above the train to get an aerial perspective of the long silver streak against the red earth. A drone would have done the trick!</p> <p>On the Nullarbor, there are virtually no trees and the horizon is dead flat… or ever so slightly curved. The word is derived from the Latin ‘nullus’ meaning nothing or none, and ‘arbor’ meaning tree. Known to the Aboriginal people as ‘Oondiri’ meaning ‘the waterless’, the Nullarbor was created about 25 million years old when it emerged from the sea. The plain is staggering in size covering an area of nearly 20 million hectares, twice the size of England.</p> <p style="text-align: center;"><img style="width: 500px; height:281.25px;" src="https://oversixtydev.blob.core.windows.net/media/7820117/image_.jpg?width=500&amp;height=281.25" alt="" data-udi="umb://media/eff378dabcf9456ab869bc9ebcb66e05" /></p> <p style="text-align: center;">Caption: <em>I was mesmerised by the landscape of the Nullarbor.</em></p> <p>For a Kiwi accustomed to landscapes crowded with hills and mountains, the sight of a flat horizon was literally unbelievable. I was staggered by the austerity of the straight line illuminated by the glow of the dawn.</p> <p>It’s the polar opposite of train travel in Switzerland. There the landscape is demanding, constantly yelling ‘Look at me, Look at me’ – you dare not blink let alone go to the bathroom for fear of missing something spectacular. Here there is an absence of anything to focus on. The vast terracotta landscape is scattered with stubbly grey-green vegetation and white rocks as far as the eye can see. The nothingness is soothing.</p> <p>Back onboard, I stayed in my cabin for a while, gazing out the window, hypnotised by the wilderness. The rocking motion and the landscape flickering by was incredibly relaxing and soporific. It gave my busy brain the time and space to wander, drift and range free.</p> <p>It was such a novelty. Nowhere have I experienced such nothing-to-do-ness.</p> <p>There was no wifi and only sporadic internet signal which turned out to be a blessing. There were times when I switched my phone off completely which would have been unheard of at home. No computer, no housework, no laundry, no cooking, no gardening, no deadlines… it was sheer bliss.</p> <p style="text-align: center;"><img style="width: 500px; height:281.25px;" src="https://oversixtydev.blob.core.windows.net/media/7820116/image_.jpg?width=500&amp;height=281.25" alt="" data-udi="umb://media/a1f0e10d2d3f401686e676b9054c41f2" /></p> <p style="text-align: center;"><em>The Indian Pacific streaking across the Outback.</em></p> <p>I also relished the absence of choices. The days were entirely mapped out for me. I didn’t have to navigate or make decisions about what direction to take. I could not possibly get lost on this trip.</p> <p>It seemed to lower my heart rate and allow me to quieten the incessant voices in my head. A feeling of great peace enveloped me.</p> <p>I became so accustomed to the lack of visual stimuli, I nearly leapt out of my skin when I spotted emus and kangaroos fleeing the noisy intrusion of the train. Apparently some camels appeared while I was snoozing- I was quite annoyed with myself for having nodded off.</p> <p>Having missed the camel sighting, I was egged on by my new Aussie mates (NAMs) to sample them for lunch instead. They no doubt thought I’d baulk at the idea but the camel tagine with coconut rice and coriander was very tasty and surprisingly tender. The wild berry, mint and natural yoghurt parfait sprinkled with almond and hazelnut crumble was pretty good too.</p> <p>Mid-afternoon on the second day of our journey, we stopped to take on water and fuel at Cook, population four, in the middle of the Nullarbor.</p> <p>Cook is seriously remote – it’s 1138 km from Adelaide, 1523 km from Perth and 100 km on an unsealed track to the closest major road, the Eyre Highway. The nearest town is Ceduna, a five-hour drive and the local doctor is at Port Augusta, a 12-hour drive.</p> <p>Once a thriving town of 200 residents, Cook is now a ghost town, its school, hospital, tennis courts, swimming pool, golf course, shops and houses lying eerily quiet and empty.</p> <p>Small service settlements like Cook were established 30km apart on most remote sections of track on Nullarbor to support the trans-Australia rail link, completed in 1917. But the town effectively closed down in 1997 when the railway was privatised. As the population dwindled, Aussie humour still prevailed with signs like: ‘If you’re Crook, come to Cook’ and ‘Our hospital needs your help. Get sick.’</p> <p>There’s a long-drop with ‘EFTPOS Here’ written on the corrugated iron wall and ‘Deposits Only’ beside the wooden toilet seat.</p> <p style="text-align: center;"><img style="width: 333.3333333333333px; height:500px;" src="https://oversixtydev.blob.core.windows.net/media/7820115/image_.jpg?width=333.3333333333333&amp;height=500" alt="" data-udi="umb://media/3f75c4d30a944f628cab7a71621ef994" /></p> <p style="text-align: center;">Caption: <em>A sign near the abandoned hospital at Cook - 'Our hospital needs your help. Get sick.’</em></p> <p>The town’s twin jail cells were a sobering sight. Built to hold the unlawful or unruly until the next train transported them out, the buildings were matching ‘his’ and her ‘cells’ with a small barred window at the top and a peephole in the padlocked door. With summer temperatures reaching 49 degrees C, imagine the heat inside those corrugated iron boxes. I doubt there was much recidivism!</p> <p>Many of the buildings were condemned so we were warned to steer clear of them. I tried to visualise children running around in the school grounds and the residents playing tennis, golf and swimming in the pool but all I could see and hear were faint shadows and echoes… ghosts perhaps?</p> <p>Others ventured into the desert but over lunch one of my NAMs pointed out the window at the scrub and mentioned the words ‘taipan’ and ‘lots’ in the same sentence so I stuck to the track.</p> <p>The residents were obviously an optimistic bunch. In 1982, volunteers planted 600 saplings in ‘The Greening of Cook’ campaign. A few survived, a testament to their endeavours, and are now the tallest trees on the Nullarbor.</p> <p style="text-align: center;"><img style="width: 0px; height:0px;" src="/nothing.jpg" alt="" data-udi="umb://media/afadd04e036643c8816b67d06379e017" /><img style="width: 299.9669093315685px; height:500px;" src="https://oversixtydev.blob.core.windows.net/media/7820114/image_.jpg?width=299.9669093315685&amp;height=500" alt="" data-udi="umb://media/afadd04e036643c8816b67d06379e017" /></p> <p style="text-align: center;"><em>Caption: Justine at Cook on the Nullarbor Plain.</em></p> <p>Cook is located on the longest stretch of straight train track in the world – there are no corners for 478 km from Loongana in Western Australia to Ooldea in South Australia. When the train finally came to a slight bend in the track by late afternoon, I peered out the window and could just make out the tail-end carriage.</p> <p>After Cook, there was even less vegetation but I never once felt tempted to pick up my book. I was contented to chat in the lounge with my NAMs or daydream in my cabin.</p> <p>That’s one of the wonderful aspects about train travel. You can choose to socialise or not as you please. Some passengers enjoyed the solitude and privacy of their cabins while others frequented the lounge and bar from dawn until well after dark.</p> <p>I also enjoyed listening to the stories broadcast on my cabin radio and reading about the colourful characters associated with the history of the train.</p> <p>Daisy Bates was one such person. An Irish immigrant who arrived in the country in 1882, she lived in a tent in Western and South Australia working tirelessly as an advocate for Aboriginal rights against the assimilation policy of the day. Dressed in a long Victorian gown, boots, veil and gloves, she was known as the Great White Queen of the Never Never, and spent 40 years documenting Aboriginal culture, history, beliefs and customs.  </p> <p>Daisy lived for a time at the railway siding at Ooldea and died at the grand old age of 91.</p> <p>When the Aboriginal people first encountered the steam train at Ooldea, they thought it was great white snake carrying wicked spirits.</p> <p style="text-align: center;"><img style="width: 0px; height:0px;" src="/nothing.jpg" alt="" data-udi="umb://media/54afe32d91df4f44a54e8850f489d763" /><img style="width: 500px; height:281.25px;" src="https://oversixtydev.blob.core.windows.net/media/7820113/image_.jpg?width=500&amp;height=281.25" alt="" data-udi="umb://media/85da58e3ed0c4a61a3637960f7c57006" /></p> <p style="text-align: center;">Caption: <em>Sunset in the desert. What an awesome sight.</em></p> <p>People-watching was another of my favourite pastimes. A couple of mysterious chaps caught my eye. They looked like secret agents in a spy movie and would have fitted well in an Agatha Christie thriller.</p> <p>By dusk, the landscape had changed to undulating red sand dunes dotted with ragged, wind-sculpted gum trees. I watched as the dying sun flickered behind the gums and sank below the horizon. A knock on my door from one of my NAMs signalled it was high time I joined them in the lounge where Mattie was leading a lively singalong session. Barman Brendan was so busy mixing cocktails, his hands were a blur.</p> <p>Dinner was another delicious feast with three or four choices for each of the three courses – the highlight for me was the spicy Asian dumplings entrée, one of my all-time favourite dishes.</p> <p>We trundled on sedately through the night at an average speed of 85km/h with a top speed of 115km/h. The swaying motion was enough to make me feel mildly wobbly whenever I disembarked on terra firma but was a wonderful sedative at bedtime. Train travel is great therapy for insomniacs.</p> <p><em>Read Justine’s account of </em><span style="text-decoration: underline;"><strong><em><a href="http://www.oversixty.com.au/travel/domestic-travel/what-it-s-like-travelling-across-australia-on-board-the-indian-pacific">Day 1 on the Indian Pacific</a></em></strong></span><em>. To be continued… Look out for the next part of the Indian Pacific travel series next Wednesday.</em></p> <p><em>Justine Tyerman was a guest of Rail Plus and Great Southern Rail.</em></p> <p><em>* </em><em>The Indian Pacific is a four-day, three-night 4,352km, 65-hour journey from Sydney to Perth and vice versa operated twice a week by Great Southern Rail. <a href="https://www.railplus.co.nz/australia-by-rail/australias-great-train-journeys/indian-pacific/itinerary.htm"><strong><u>Find more information here. </u></strong></a></em></p>

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