20 of the most surreal natural phenomena – explained
<p><strong>Behold</strong><br />I don’t know about you, but being cooped up in the house has made me yearn for the majesty of nature like I’ve never quite yearned in the past. Sure, prior to quarantine I might’ve gone weeks without seeing moss and not thought twice about it, but now that I cannot venture out of my home to see salt flats or rainbow eucalyptus trees, I am simply beside myself. But that doesn’t mean I can’t use this time to educate myself about them – I dare you to try to stop me from marvelling at Skógafoss waterfall in Iceland and other natural phenomena. Take a look at some of nature’s most dream-like creations, and maybe they’ll earn a spot at the top of your bucket list.</p>
<p><strong>Moonbows</strong><br />Much like rainbows, these colourful nocturnal arches occur when light (from the moon, in this case) reflects and refracts off water droplets in the sky. But moonbows are much more rare than rainbows – the natural phenomenon happens only when the moon is very low, the sky is dark, and rain is falling opposite the moon.</p>
<p><strong>Sun halos</strong><br />Similar to moonbows, sun halos, or a circle rainbow, form much higher in the sky when light reflects through ice crystals forming a perfect circle. They appear as a large circle of white or coloured light around the sun.</p>
<p><strong>Brinicles</strong><br />What Alec Baldwin describes on Frozen Planet as “icy fingers of death,” brinicles are underwater stalactites, or hollow icicles, that form when cold salt water freezes. In the right conditions, brinicles can reach and pool on the ocean floor, eventually freezing slow-moving bottom-dwelling creatures like starfish.</p>
<p><strong>Shooting stars</strong><br />Shooting stars are actually meteors, or small rocks that have entered the Earth’s atmosphere. The light you see is the particles heating up and burning. Stargazers can expect to see a shooting star every ten to 15 minutes.</p>
<p><strong>Sinkholes</strong><br />A perfect example of how a natural phenomenon can be dangerous is the Florida man who was swallowed by a sinkhole under his bedroom. Sinkholes most commonly occur when water, made acidic by contact with plants or carbon dioxide in the air, erodes soft rock such as limestone, gypsum or dolomite underground, forming a deep cavern.</p>
<p><strong>Whirlpools</strong><br />Formed at the meeting of opposing currents, whirlpools are often much more ominous in fiction than in real life. The most powerful whirlpools, called maelstroms, are formed in narrow, shallow straits with fast flowing water, or at the base of waterfalls, but the speed of the swirl rarely exceeds 30km/ph.</p>
<p><strong>Glowing beaches</strong><br />Some beaches around the world glow at night. This natural phenomenon is caused by phytoplankton in the water that gives off light when agitated by the movement of waves and currents. These microorganisms can be seen at beaches in Australia, Malaysia, Thailand and many more around the world. The image above is a long exposure shot of a blue fluorescent wave of bioluminescent plankton in Thailand.</p>
<p><strong>Light pillars</strong><br />Light pillars are colourful beams of light that shine down from the sky, typically during sunrise. They are sometimes also referred to as solar pillars or sun pillars. Light pillars occur in colder climates when light reflects off ice crystals in the air.</p>
<p><strong>Waterspouts</strong><br />Some might mistake a waterspout for a tornado moving over a body of water, but in reality, a waterspout is a type of cloud. Waterspouts are rotating columns of air over water and are much weaker than tornados. They mainly occur in tropical and subtropical climates.</p>
<p><strong>Volcanic lightning</strong><br />Thunderstorm lightning has nothing on volcanic lightning which appears during a volcano explosion. This lightning forms in the volcanic plume – the cylinder-shaped column of volcanic ash – after it erupts, according to National Geographic. The particles that make up the plume compress underground. Once these particles eject above ground the density changes. Plus, the friction between particles charges them. They separate as they go up, creating space for electricity or lightning to flow between particles, per National Geographic.</p>
<p><strong>Blood falls</strong><br />In Antarctica, the famous Blood Falls – a blood-red waterfall pouring out of the Taylor Glacier, are found in the McMurdo Dry Valleys. Scientists and geologists first thought that the water was the colour red because of algae, according to Atlas Obscura. Research by the University of Alaska Fairbanks, however, found the red colour is thanks to oxidised iron in the brine saltwater. We see the falls thanks to a fissure allowing the water to flow from the small, trapped body.</p>
<p><strong>Frozen lake bubbles</strong><br />Lake Abraham in Alberta, Canada, features some beautiful frozen, trapped, bubbles of methane. Methane bubbles form in water when bacteria feasts on leaves and animals in the water. The bacteria eat the matter and ‘poops’ out methane, which turn into floating bubbles in frozen water, according to Smithsonian Magazine.</p>
<p><strong>Salt flats</strong><br />There are some well-known and beautiful salt flats, also known as salt lakes in Western Australia, South Australia, the Northern Territory and Victoria. No matter their location, salt flats are all thanks to the evaporation of water and the concentration and precipitation of salts and other minerals dissolved in it, according to the New York Times. They can differ in their water source which could be a lake, groundwater, or one of many other water sources.</p>
<p><strong>Glow-worm caves</strong><br />Even worms, although small and slimy, are a natural phenomenon – especially glow-worms and their caves. Most of these caves are in New Zealand and Australia. The Waitomo Caves in New Zealand are the most well-known, having formed more than 30 million years ago. The science behind the glow-worm caves is interesting. In fact, they technically aren’t ‘glowing worms’ at all. According to the New York Times, fungus gnat eggs hatch, their larva constructing mucus. That mucus coughs up silk strings collecting droplets of more mucus. This is the net that illuminates and attracts flies or other victims for the worms.</p>
<p><strong>Rainbow eucalyptus trees</strong><br />Rainbow eucalyptus or rainbow gum trees hails from the Philippines and Indonesia. The colourful tree stripes are actually strips of old and new bark. As the thin bark layers peel away, they reveal younger ones with brighter colours. The youngest bark is green then purple, red and brown as the tree ages and loses chlorophyll. Eventually, the bark becomes totally brown again before repeating the shedding cycle, according to nature.com.</p>
<p><strong>Travertine terraces</strong><br />Travertine forms as a result of calcium carbonate precipitation from geothermal waters, according to New Zealand’s University of Waikato. The travertine builds up forming terraces over time. When hot water full of carbon dioxide flows through limestone, it dissolves. It carries calcium carbonate to the surface of the travertine, per Atlas Obscura. Still, more research shows there might be other reasons for their formation. Bacteria in the water could catalyse the minerals, forming the terraces, according to Science Magazine.</p>
<p><strong>Sandstone waves</strong><br />These sandstone waves were originally dunes in Arizona, USA. Dating back more than 190 million years, the ‘waves’ are made up of intersecting troughs of sandstone turned to rock. According to Atlas Obscura, the dunes form vertically and horizontally, and slow erosion, thanks to wind and rain over time, reveals their wave-like look. Sandstone waves are a must for avid hikers in the American Southwest.</p>
<p><strong>Desert roses</strong><br />Desert roses are a special crystal group formed by rain or flooding in desert regions where there are trapped sand particles. Switching between wet and dry conditions forms the crystals while trapping grains of sand. Although most form from gypsum, baryte and celestite roses exist, too.</p>
<p><strong>Nacreous clouds</strong><br />Nacreous clouds look like light waves of various colours. They are rare since they’re only visible within two hours after sunset or before dawn. However, they’re more common during winter time in places with high altitudes, like in Antarctica, Scandinavia, Iceland and Canada.</p>
<p><strong>Permafrost explosions</strong><br />This natural phenomenon is thanks to frozen, trapped methane, similar to the bubbles seen here in Lake Abraham, Canada. Heating these larger-scale bubbles results in huge bursts, according to Business Insider. The warming temperatures in Arctic zones thaw the ice, releasing the gas and creating permafrost explosions.</p>
<p class="p1"><em>Written by Beth Dreher. This article first appeared on <a href="https://www.readersdigest.com.au/culture/20-of-the-most-surreal-natural-phenomena-explained?pages=1"><span class="s1">Reader’s Digest</span></a>. For more of what you love from the world’s best-loved magazine, <a href="http://readersdigest.com.au/subscribe"><span class="s1">here’s our best subscription offer</span></a>.</em></p>
