How Do Tidal Bores Work?



Today's episode is brought to you by IBM. SMART is open open is smart i._B._M.'s combining their industry expertise with open source leadership of Red Hat. Let's unlock the world's potential. Let's put smart to work learn more at I._B._M.. Dot Com slash slash red hat welcome to brain stuff production of iheartradio. Hey brain stuff lauren Vogel. I'm here. The Alaskan coast is as dramatic as it is vast and it spans over thirty three thousand miles or over fifty four thousand kilometers the forty-ninth U._S. state owes. Its very name to this sweeping ocean border. Alaska is an English language corruption of an Alouette term that according to one translation means the shore where the sea breaks its back and if you drive out to a place called Kernigan arm in the Gulf of Alaska at just the right time you get to watch some aquatic action. That's pretty spectacular attorney can arm waterway is a northern branch of the cook inlet the cuts into the Greater Anchorage area. Here the water normally flows out toward the inland but shortly after low tide waves move in the opposite direction and travel upstream and these waves can epic in scale the biggest waves are up to ten feet or three meters tall. This is is a well known example of bore tides also known as tidal bores or just bores and writing them has become a rite of passage for many surfers in the Pacific northwest while this phenomenon has been seen at numerous locales around the world it requires a very specific specific set of conditions but before we dive into those it might be a good idea to go over some basic title science by and large tides are gravity's handiwork due to the gravitational influence of our moon plus the inertia of our movement through space the ocean is always bulging out a bit on opposite sides of the planet while Earth rotates at passes through these tidal bulges that means your favorite seaside beach will experience high tide when it enters each old and low tide as it travels between them. So plan your sand castle contests accordingly because earth finishes a new rotation around its axis once every twenty four hours most coastal areas witness to high tides and two low tides per day but there are loads of exceptions the layout of Continents Islands and Peninsulas impedes tides in certain places a parts of the Gulf coast for example only see one daily set of high and low tides no matter where you are though the tides will vary in strength from day to day all over the world during full moons in new moons when the Earth Moon and sun are arranged in a straight line high tides are especially high and low tides are really low. We call these extreme tides spring tides which despite the name occur all year round not just in the springtime but let's turn back to turn again arm although it's shallow and narrow the turn again feeds into a broad bay mainly cook inlet on this wide expanse the difference between high and low tides. I e the tidal range. Can Be Stark the cook inlet water level at high tide. Maybe thirty five feet or ten and a half meters higher than it was during the preceding low tide and these are exactly the ingredients needed to produce tidal bores after a low tide on cook inlet water funnels into the tournament arm generating bore waves that barrel inland sometimes travelling at speeds up to twenty four miles per hour. That's nearly thirty nine kilometers per hour since bores only happened when the circumstances are just right not all waterways the touch the ocean can get them in total. There are eighty or so rivers around the globe that undergo tidal bores the phenomenon tends to be at its most dramatic during spring tides whereas the turning and arm has twice daily tides the Amazon River only receives chiefs bores on the days of new and full moons once the spring tides arrive water from the Atlantic comes charging up the Amazon River temporarily reversing its natural flow waves generated by this process have been known to journey about five hundred miles or eight hundred kilometers. There's inland code AROCCA. The Amazon Boers attained considerable size measuring upwards of thirteen feet or four meters tall in some cases the strongest poor Arocca events of all take place every year on the equinoxes to to prepare for these searches local residents move their boats and livestock safely away from the Amazon accidents do still happen though Jacques Cousteau wants lost a boat depar- AROCCA waves while filming in South America Tidal bores impact ecosystems wherever they occur trees he's rocks and river bottom sediment get pushed around by the waves and those aren't the only things they turn up down in the Amazon current reversals can leave stunned or dead animals floating in the water attracting hungry piranhas strong bores are also prone to object fish from rivers stranding them on beaches or launching them into the air. That's why Alaskan Bald Eagles Australian sharks and Malaysian crocodiles like to scavenge in the wake of tidal bores big boars attract humans as well Sao Domingos Dough K._p._m.. Community the borders the Amazon has been. Hosting the Brazilian National Per Arocca Surfing Championship since one thousand nine hundred nine Alaskan wave chasers flocked tiny arm shortly before or after every spring tide when the boers are their largest. Oh and there's one last thing we should mention about boar tides they roar the waves produce a great deal of turbulence wildest placing sediment scraping up shoals and unleashing loads of air bubbles at all those sources APP and you've got a recipe for thunders low-frequency booms the can be heard of vast distances episode was written by Mark Van Chigney and produced by tyler playing brain stuff is a productive iheartradio's has works for more on this and lots of other swell topics visit our home planet has networks dot Com and from our podcast iheartradio visit the iheartradio APP apple podcasts or wherever you listen to your favorite shows your network decades pioneering television broadcast once and never seen again. There was nothing else like this on early television generation of American musicians.

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