Watch this video first ► • How the tides REALLY work Learn more at Waterlust.com Join marine physicist Dr. Patrick Rynne as he explores the science behind tidal bores and see what happens when he tries to surf a bore in Canada!
i live 10 minutes away from moncton and apparently in the 60's the wave was a lot bigger but construction work down river messed it up. hardcore surfers would come from all over to surf it
Very interesting. I've heard explanations for tidal bores, but they were missing the all-important detail about the speeds matching, so the explanations didn't sink in for me. Now that I've watched both videos, this one and the "How the Tides Really Work", I've given a little more thought to something I've been wondering about for years concerning tides - where does the water come from at high tide, and where does it go at low tide? I'm talking about the individual water molecules, and in the open ocean. Obviously a relatively narrow channel connecting a large body of water to the ocean will have large tidal currents flowing in and out through the channel. But in the open ocean, it's not so obvious. Clearly the high/low water molecules don't come from the region where the tide is currently low/high, since that's a few thousand miles away. So it must be analogous to filling a kitchen sink with water, where the required water is already in the pipes of your house. After some thought, my conclusion is that the individual water molecules travel such a small distance that you can say the water doesn't move (i.e., flow) at all. Here's my reasoning. Consider a square mile of open ocean in an area where the water depth is a one hundred feet, and the tide on a particular day is 10 feet between low tide and high tide. A additional volume of water one mile long by one mile wide by ten feet high is a huge amount of extra water. Consider a vertical slice of this volume that is one mile long by one inch wide by one hundred feet deep. If you could pick up this slice of water and place it on top of the adjacent water, the water level would be one hundred feet higher. So to make a ten foot height increase, you'd only need to move a one-tenth inch slice of water and spread it over the adjacent inch of water. Nothing in this thought experiment depends on the choice of a one-inch slice, it could just as easily be a thousandth of an inch or a millionth of an inch. So the individual water molecules don't have to move at all, they essentially stay in place, with some percentage of them rising in height. This seems really counterintuitive, that such a huge volume of water could appear and disappear with essentially zero water current flow. Is this analysis all wet?
I appreciate your video, but please know the photo of the aircraft with the cloud around it at 5:27 is not a sonic boom, it is caused by pressure and humidity.
Great educational videos! This and the accompanying tide video were extremely helpful in helping me understand just what the heck is going on. Now to search through your content to see if you've done a video on standing waves...
I have lived about 5 metres from a river with a tidal bore for 20yrs, the river Parrett in Somerset. I can see it from my window and regularly walk along the bank side paths. In all that time Ive only ever seen the bore twice lol. The local authorities have now started to build a tidal barrier which will unfortunately likely put a stop to it
LOL, the closing comment was backwards: you don't "observe science in action in the real world", you observe nature in action and verify or disprove the scientific models that have been created to describe the particular phenomenon.
tsunamis are not rough waves, they are long waves caused by some external perturbation such as landslides, rock slide, ice slide or some kind (not all) of earthquakes. Not all tsunamis are dangerous, only the big ones. Rough waves are more special that are rare and their height is 2 as the highest surrounding waves, the nature of those is still studied and explained on statistics levels. Cool video esp the surfing part!!! If I understand well it is more the case of wave (tide) on current (river) and the interaction - not just slope varying in right way. It makes the amplitude got up and makes wave steeper till it breaks. On youtube there is another cool video explaining hydraulic jump and the subcritical, critical and supercritical speeds.
That has got to be one of the best "explained" videos I've ever watched on RU-vid. The way it was explained along with visual aid was perfect for my non scientific brain to comprehend. That video of the surf with multiple camera at work was amazing. The tidal bore resembled the tsunami waves Ive seen on videos. Very fascinating phenomenon. That's for teaching me something new today!! Subbed your channel and love the merch you have. Will def be getting something for the comiNg summer season.
I think the explanation of sonic booms isn't quite right. Any plane going faster than the speed of sound makes a sonic boom, it's not just planes going at exactly the speed of sound. So I'm not sure that a tidal bore needs the speed of two types of wave to happen to match.
I experienced one of these in Moblie Bay in Alabama while kayak fishing in the marsh. It had been dead silent for hours and we heard water rushing. We look behind us and there are 3 waves stacked on top of each other. They pass us and we noticed the water on the shore was about 6" higher than it had been. The wind was blowing out and the tide was coming in. I believe the wind had pushed all of the water out of the small creek when suddenly the tide overcame it and all of the water came in at once. It was very neat to experience.
Abstract : The energy that dominates the earth is very great, some of it is natural, like the heat of the sun and volcanoes, and some of it is human action, by cutting down trees, without replacing them and cultivating in their place... There are five forces that control or dominate the planet... 1- The first theory (horizontal dynamic movement) and its end... The occurrence of storms, rain, floods and snow, at unexpected times and places, is because of the expiration of this theory, which needs to be balanced... 2- The second theory (vertical dynamic movement) and its end... This movement or force controls or dominates the earthquakes, earth cracks, drying up of rivers and lakes, earth openings, mountain collapses, and the emergence of drinking water springs on the ground... It becomes out of control... These phenomena increased due to the end of this theory... The third theory: it is water that rotates the earth... The fourth theory: the Earth's axis of rotation has tilted 2° degrees... The fifth theory: The Earth has a new orbit... These studies had completed and sent on July 26th 2000 YOUSIF A TOBIYA
Now, now, now...The Earth is more than 50,000 km away from the Moon, and is close to the Sun and the planets. Therefore, the Moon’s terrain cannot be seen with the naked eye like before...The Earth will be lost in the depths of infinite space... This phenomenon confirms my fifth theory (the earth has been lost in the depth of space)... Yousif A Tobiya
You all talk about tsunami, but you do not know when? it's going to happen? I will explain and discuss this phenomenon at any scientific conference... Yousif A Tobiya
You can imagine the Earth without water, as water balances the shape of the Earth, its rotation around itself, and around the sun. Tides are considered a safety valve for the Earth and its rotation. As the water melts, the Earth slows down its rotation. Water has increased due to the melting of the ice caps in the poles and the Himalayas, and thus, the rotational force also increases... Now: The length of the year now is [365 1/4 +_(2 minutes)]... These studies were completed and sent on July 26, 2000... Yousif Ayoub Tobiya
I live in Anchorage, and there are people surfing the tidal bore in Turnagain Arm all the time. I'm not aware of anyone who's died or been injured doing that specifically, scary though I'm sure it is. However, because our tides are so drastic, people will try to walk to islands and other coasts during low tides. Unfortunately, the Cook Inlet's bottom is fine glacial silt that acts as a non-Newtownian fluid: If you run across it, it's hard as concrete, but if you stop and stand there it'll slurp you up. People die on a somewhat regular basis from that, maybe once or twice a decade. They start sinking, can't get out (a man was torn in half when a helicopter tried to pull him out many years ago), and drown. Great video!
I’ve been to Turnagain and surf so I was warned not to go out on the mudflats there as people allegedly have died in the past …they weren’t surfers they were clamming or something and got stuck in the mud when the tide came in
Thanks for the explanation (and the demonstration)! We came across this video trying to understand what we accidentally witnessed - the Lupar river changing direction right in front of our eyes while holidaying in Borneo, Malaysia. They also have an annual tidal bore festival in which one of the activities IS surfing the wave! (Look for Benak festival in Sri Aman)
Good video. Driving through Scotland I was lucky enough to arrive at the Connel Bridge just as the tidal bore, known as The Falls of Lora, was coming in. There were some kayakers on the water in river running kayaks. I'm a sea kayaker so I could understand some of what was going on. The kayaker closest to the north shore was really struggling, though the current and bore didn't look any more difficult than beach landing through surf. Clearly there were more forces than it appeared (from shore. I was in the car park) He was rescued and towed ashore by his friends while others retrieved his yak and paddle. And I would expect most of these bores to be muddy, possibly sandy. After all what flattens out into a long slope better than mud and sand?
must admit I've never heard the Falls of Lora called a tidal bore, only a tide race. Usually the waves are more like standing waves under and around the bridge, rather than running through on their way miles inland. More like the Swellies than the Severn. I've sea kayaked there once; the currents and eddylines were ferocious! But it is impressive watching the experts play...
There is no perfect balance of the wave speed and tide speed... So long as the tide rises fast enough and the wave speed is slow enough, you get the bore. This reminds me much more of a hydraulic jump. Fast supercritical water flowing in one side, hydraulic jump, subcritical water behind. The shallow water wave speed is √(gh); if the point where the ocean surface is equal to the river height moves faster than that, then there is no way for the information to propagate upstream. The river water upstream doesn't know that the tide has risen, it just keeps flowing as usual until the wave comes in - basically a shock wave.
That star represents Crissy Field Marsh, in San Francisco, California. Records show a tidal bore can form there around high tide, but we're not sure if it's still a regular occurrence.
That's an interesting theory. There was a tidal bore in the Seine a while ago, but works on the shore destroyed it. I'm not sure at how those works could have ruined the wave. Ideally according to the theory you present, there wouldn't be any tidal bore if there was absolutely no perturbation already in the water. For a plane, you can imagine any air molecule hitting the plane would create a perturbation. But I think even Ideally, with a perfectly continuous fluid, you would still have a shockwave. I would say those perturbations are not real, they might be a way to visualise the dispersion the compression front experiences through the medium it propagates in.
Spot on observations! The metaphor of the airplane and sound barrier is, to a degree, a simplification as it doesn't get into the finer details of how the waves are created in the first place. It's value really is in illustrating that there is a difference between shallow water wave propagation and the motion of the tidal front. What we don't present is HOW the upstream flow of water plays a role in wave formation, as we felt getting into those details would make the video too dense for the average viewer to appreciate. We couldn't find a clear and succinct way of explaining that aspect of the phenomenon, but it's something we hope to tackle in an upcoming video that explains how river surfing works, as the underlying physics are similar. Really appreciate your thoughtful comment and observations!
@@Waterlust Thank you! I heard a while ago that tidal bores were not yet clearly understood, but I never got even the beginning of the explanation for their formation. So I'm really greatful for that. On your river wave topic, I remember having annoyed my fluid dynamics teacher with Tcheaupo waves that looked like they were sucking the water in front of them, my theory at the time was that it might explain part of why they broke so square, but that was a purely math free interpretation, so, not confirmed. It just looks like the front of the wave goes under the average height. Once I thought that if an ocean wave broke it was because the top of the wave was at a higher height compared to the bottom, so it meant it should go faster as stated by the propagation equation. After that, a teacher gave us the very same explanation which didn't reassure me but on the opposite made me question that simplistic theory. Since it's highly non linear, I doubt it's that simple and the only explanation. Now I think the flow coming from the front of the wave participates in the rising of the face, like how a river wave is created when it goes over an obstacle and sort of bounce back after that. The same type of waves exist in the air and are used by sail plane. If you search on john john Florence's page, or his brother Nathan, you will find and incredible shorebreak that is so hollow, it litteraly sucks the water in front of it, accumulate waves, and then a 50 cm wave becomes a 2m pipe. Here it is ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-SfUWAc_J_9o.html Look at the view, it's incredible.
You're missing the coolest tidal bore!! Anyone who wants to see some good examples look at Skookumchuck Rapids in BC or look up the tidal bore coming through the discovery Islands off of Vancouver Island, It's pretty gnarly
A tidal bore is like you, in sync speed-wise with the rotation of the Earth and the momentum of the gravitational effects of the moon at its strongest. It's as if the Earth was moving under you while you stayed lifted up above it based on the moon pulling you up in a malleable situation support-wise. You surfed the Earth.
@@Waterlust It's not really true though. The rotation of the earth is a speed of about 1,000mph at the equator. Zero at the poles, presumably 500mph ish at a the 45 degree latitude of Fundy Bay.
It’s a home built trailer using a kit from a company called Chesapeake Light Craft. We have a series of videos on our channel documenting the build. Here is a link to an overview video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-nER79I4iSxc.htmlsi=V5jWVWeP8-4gVXZv
Plenty of ways to fund one’s work that has nothing to do with driving positive change. That just happens to be what we focus on…and we wouldn’t call that work depressing, we find it inspiring
