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Sept. 27, 2021 - Clif High
33:02
Wave Woo - Explorers' Guide to SciFi World

Tsunami waves....how they work.

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Hello humans.
Hello humans.
27th of September.
People are getting a little weirded out by La Palma.
Canary Islands volcano.
And I thought we'd talk about wave woo.
Waves are really interesting.
I've been a sailor in on boats all my life.
Built my first boat, helped my father build my first boat.
Or help my father build his his boat when I was five years old, four years old even.
Built a number of boats myself, go out sailing and stuff, so live on the coast.
So we're going to talk about waves and the dynamics of waves.
So here's a sort of a picture of what's kind of going on.
This is like the volcano.
And here's the fissure.
And there's the smoke and stuff.
And this is the island, right?
And the water is over like this.
Here, let's put water in blue.
I've got them, might as well use them.
Anyway, so this is the island, and here's the water.
And it goes off.
Then there's a big distance, and here's water, and here's the east coast of the US.
We'll do this in a minute.
Anyway, so the island actually, of course, goes way the fuck down in the water like that to the bottom of the ocean.
And it's got a vent and spewing lava coming from way deep.
Now I'm going to show you this image here.
Let's see.
There we go.
So we're looking here at a picture of the um where the cursor is of the uh island, and then there's this is from somebody I don't not sure who it is.
Um showing you the speed at waves it says here 130 to 160 uh feet high, moving at a speed of 650 miles per hour and travel up to 12 and a half miles inland.
And I'm gonna dispute all of that.
This is a bunch of horseshit, guys.
It says over here in North Africa, Northwest Africa, waves would be over 300 feet high, and waves in the UK are gonna be uh 16 to 23 feet high.
Now that's actually might be accurate, okay, and I'll explain that in a bit.
But but let's get into this.
There's a bunch of different kinds of waves, okay?
There's tidal waves, uh, those are caused by tides.
There's displacement waves.
That would be like when you go to a pond and you throw a big rock in there and you get that big splash back and stuff.
You're displacing water by pushing it out of the way.
Then there's tsunamis, okay.
Tsunami is most often started by a displacement, but it's not a displacement wave.
Tsunami is force moving through the water.
Okay, so here's some interesting things about this.
This volcano, the the fear is that the um the magma, sorry about that.
The magma in the eruption is gonna go get so fierce that it'll crack off part of this this island, and that the island would would crack like something like this.
Let me go back to the other one here for a second.
Okay, so that the island, so that this part of the island would crack off and it would sort of slide off here, and that this mass would move down this way.
Okay, and so this mass up here of the island and everything on it is gonna maybe shift down here.
That's the fear.
Now, this appears to be an ordinary eruption.
Ordinary eruptions are good.
It means there's no building pressure down here that would blow this thing uh off that way, right?
It's because it's being released by the uh the eruption.
So this eruption is a good thing.
And um that yet the fear of it is I mean, people don't understand that it's much better to have it erupt and get get that pressure out of there than to just keep building the pressure and then it would blow and crack and everything would slide down.
That's what would cause a tsunami, but it's gonna cause a tsunami by displacing this amount of water with this mass and basically shoving the water this way, and that's that's what creates the tsunami.
Uh but here's the thing.
Like on this uh on this image here, there they're afraid of waves 130 to 160 feet high moving at a speed of 650 miles an hour.
Well, that's horseshit because 650 miles an hour is close to 700 miles an hour in the sound barrier.
And to move that fast that much, you're gonna have to displace a huge amount of air.
The friction would instantly erode it, but water does not work that way.
And I'll explain here what happens with these waves.
Alright?
So let's look at first what happens with a tsunami itself.
Alright, so if this were to occur, this mass here would slide down half the island, they're saying more or less, would slide down to the bottom of the ocean.
In doing so, it's gonna push out all that water and push it around on that big circle that we saw there and head some of it towards the east coast.
But is is this coming down here going to raise the water up a hundred and thirty feet to a hundred and sixty feet or something like that?
No, it's not because there's mathematic rules about how water behaves.
So I'm gonna I'm gonna take this part off and we're gonna go to the receiving beach.
Okay.
We see that this what happens here is that the water is displaced by this amount of mass, but it does not raise up that much.
The reason that it doesn't raise up that much is because it is twofold.
One of the reasons is that the impetus is this way and not upwards, and so this is a force wave that is created.
And literally, as this comes down here, there's a few molecules of water that are moved a few um hundreds of feet this direction, and in doing so, they impel this force wave that starts off and it goes like this, and it goes like this through the water.
It is just a sine wave going through the water, and a certain amount of a tsunami rises out in the middle of the ocean, a certain amount of the tsunami will rise up off of the surface of the water.
Okay, but water has this three-quarter rule.
And uh we'll get into that in a second.
But this certain amount of the force here, even if this force here were to be say 900 feet deep, right?
900 feet uh deep sine wave, it's only gonna rise up here maybe 18 inches.
Uh not much more than 18 inches.
I was actually out in a tsunami wave in a boat off the east coast of uh would have been probably South Carolina at that point, um back when they were building the barrier islands, and uh we encountered a tsunami at the um uh out in the water, and it was reasonably deep water, and the tsunami for us was a maybe uh three inch, four inch lifting of our boat, and that was it.
This went right underneath our boat.
It was no big deal.
Uh we didn't know until later that it was a tsunami that rose up a couple of feet on uh the Bahamas and in some of the islands there.
The the issue about the tsunami is the danger of a tsunami, the real danger of them is that it's this amount of water being displaced, it is the force.
So this is the force that is being transmitted through the water moving that fast.
That's the danger.
And yes, over here it says 650 miles per hour.
No, usually tsunamis don't don't they max out at about 500 miles an hour and they'll even slow down because the more deep the water is, the the force has a room to expand downward and it uses itself up because it can't push the water up much more than 18 inches maximum, and it will always seek to go and expand out as much as it can within the mass of the water and dissipate itself as it's going on.
So there will not be a hundred and thirty-foot high wave rushing across the Atlantic Ocean at the um at any place.
There will be a large wave near the island as the displacement occurs, there will be a rising up of the water that will then flush back in and fill in this gap.
That's the actual displacement wave that is created when this goes off.
The resulting tsunami travels through the water as force, and you won't even see it.
Boats, big boats wouldn't even necessarily feel it underneath their keels, right?
It's not gonna knock them over or anything like that.
It does Not rise up out of the water.
Okay, so now let's let's go to the receiving beach.
Now that we understand that tsunamis are really transmitting through the water this way as force, they're not moving the individual atoms of water in the ocean.
That's not how tsunamis work.
But the danger of tsunami is the force, the sheer amount of force, okay, because the tsunami, I think it was in like the early 60s in Hawaii, rose up four inches and drowned 60 people on a beach in Hawaii, like 64 people were killed or something like that.
Have to go check my numbers.
But it was just a little tiny tsunami.
But the the thing about a tsunami is all that force keeps coming.
So it was only four inches high, crawled up the beach only four inches, but these people were trapped up against a cliff, and as that tsunami kept coming up on the beach, they couldn't get away from it, and the water kept piling up around them and knocked them over and drowned them, even though it really at their area rose up barely four feet.
But they couldn't get away from the force of it all, and the force just crushed them and they drowned in it.
But as it crawled up the beach, it was only four or five inches high.
And here's what happens with the tsunamis, okay.
So get this out of here.
Alright, so over on the east coast, it is true that a tsunami can run up inland 30 or 40 miles if you've if it's got a river there.
And that's because the tsunami is traveling up the the uh river and actually traveling through the water and moving the water in the river up further into the river through this force wave that's that comes on up.
So it has that natural channel.
Can a tsunami climb up huge amounts of height and rush into inland?
No.
Here's what happens with with tsunamis and uh stuff.
There's basic, we're gonna there's many different kinds of beaches, okay?
But we're gonna look at basically two different kinds of beaches.
Uh we're gonna look at uh the steep beach, all right, and then so this would be the water down here, and this is a steep beach that rises on up, and then you've got dunes and stuff back up in here.
Okay, as the tsunami comes on up here, there is this rule, the 75%.
It's not really 75, it's close to it, it's like 72 and a half or something, but you got the water out here, and as the um as the force wave rolls through it, it comes on up here, and as we can see, when it starts hitting the beach, it starts becoming constrained.
Okay, so just like in it's in a bathtub or something, if you're pushing on water, pushing it down onto the bottom of the bathtub, it will rise up on that edge.
And that's what happens.
As the force wave comes down here, it starts moving this amount of water up, starts trying to lift this water up.
The force wave will come on up, you'll see the water start to rise here.
First, actually, it withdraws it because as it comes on in, it pulls the water out, and then it pushes it back into you.
But the tsunami wave actually at this point starts climbing the beach, that's what it is actually called.
It climbs the beach.
And so the next wave down here is like this, and then it comes on up here.
But if this area right here, the distance of the of the grade, the angle of the surface rising on this steep beach, if this distance right here is greater,
and so it so it's horizontally it's it's going this far from here to here, if that distance A is greater than 75% of the mass of water as it rises up, that will be a cresting wave.
So, in other words, if this distance here were to actually bring the height of the water up this high in a theoretical sense, it won't get that high because it's 75% of this mass can be supported outside of the water at maximum.
So if this is your total distance of the force wave, you can only get this much to stick up above the surface of the of the water before it becomes a cresting wave.
So it would be like one fingers, it'd be like right there, so it would crest right here.
So this wave would crest right there.
And so if this next one right here is like that, well, you can only get 75% of this mass right there, and so this wave would only come on up that high.
So that's going to be the height of your tsunami.
And so based on the on the shape of the beach, and this distance A, which would be the increment relative to the sine wave that it is crossing, how much land it's it's cross, how much uh ground under the water it's crossing with each and every cycle, that determines how high the tsunami can get.
So in this case, right here, say that we do have La Palma crush off, right?
And you're you live on the east coast, but you've got a steep beach.
That is you've got blue water down here at say uh 25 or 30 feet, right uh uh out from the out from the edge of the beach.
So you can swim out 30 feet, and then it is much deeper than 30 feet out at 30 feet distant.
If you've got that kind of a steep beach, then Lapoma might be able to produce a tsunami.
Well, theoretically, a steep beach like this can never produce the height of a wave that's this will be the uh highest kind of a wave you can get is on a steep short short run beach into land like this, and so you would get the maximum force of the wave here, and you might be able to get 80 feet high, okay.
But here's the thing.
So that would be that would be an 80-foot-high wave, and that would be exceptional.
That would be very exceptional.
Most tsunamis will never ever ever, when they come up on land, get over 40 feet, because the this area right here in the in the way in which land and moving up the water erodes the force.
Tsunamis at this stage keep coming, they keep coming, but as they because this mass just keeps coming and coming for maybe 30 minutes, 40 minutes, 20 minutes, an hour, even you know, can even be very large, could be an hour.
And so you just get to keep kidding inundated with water.
But every single one of these force lines as they come through the water up here, even though this is all frothy, will have this same effect.
So, in this particular kind of a shape of a beach, it would be very hard to see that this would rise up, say much more than 10 feet off of the the beach up here where we would have houses and stuff based on this steep of a run.
Now, most beaches are not this kind of steep.
This is very uh unusual, right?
But this is what it takes to get a very uh tall tsunami.
And so you'll see these very rare tall tsunamis in places where you have this kind of a configuration.
Usually those will be river deltas that have like um that are like fjords, like uh the uh Bay of Bundy up in uh Canada up there, and some of these areas, you'll get you get these sort of fjord river basins that are rock uh that will support this kind of action and they'll raise very tall waves, but never more than 80 feet.
Now, most tsunamis are in the 40-foot or lower category, so you never get 160-foot wave, you're never gonna get a 300-foot wave that's gonna overtop a city.
Miami is safe, it's not gonna get well.
Miami is not necessarily safe, Florida isn't safe, but it's never gonna get giant wave from a tsunami that would would overtop it.
If a meteor came down close enough to Miami, you could get a displacement wave that would overtop Miami, but it would have to be fucking close.
Um, and it'd have to be giant and big.
So we're not facing that kind of thing here.
We're facing a regular eruption that probably won't cause this mountain to split.
If it does split, it will be a slide, which will produce a displacement and not or a tsunami by way of a displacement, but it won't be a propulsive displacement.
And so we'll get this kind of an effect on the waves.
Now, if you live on the more normal kind of beaches, which are a little bit flatter, you get this other effect, okay, and that is this.
Um the tiny kind of beach I live on, so my house is up here, it's a little house up here like this.
Um this cliff here is 155 feet, and then I got a long oh well that's too too flat, but I got a long flat beach.
So this is the dunes up here, and so my my beach up here is probably pretty close to a lot of beaches that are sand and gravel based.
And it's it's a long flat beach.
So my estimation is that uh from my viewpoint, 155 feet up, my horizon is approximately 13 miles out.
And at 13 miles out, I suspect that maybe we're talking 100 feet deep.
Maybe it's it's very shallow.
So it's really flat up here.
So anyway, in this kind of scenario, even if out here it went very very steep, as the force wave from the volcano would come down and expand and come down and then starts becoming constrained, it's going to start trying to rise up here.
And from my viewpoint up here, what I would see would be the water raising up here in the far distance and crashing, and then raising and crashing, and then raising and crashing, and then raising and crashing.
Because here it's going to have to crash in a much smaller distance than this, because it as it runs this way, it's going to go like that.
It'll raise it up and it'd basically be continually crashing tsunami wave here because the beach is so shallow that 75% of the force wave at this point with that depth of beach would be eight feet, maybe, right?
So for me, I would get at most maybe a four foot or an eight-foot tsunami that would be dissipating itself furiously as it as it climbed up the beach.
Because it would climb up rapidly here, but then this area here would degrade based on that 75% rule.
That's just because water is slippery and it falls around itself, so you can lift up a certain mass, and then that's it.
And so it's 75% of this distance here is basically so wherever the wherever you are in relation to this area right here, you can only get 75% of this distance rising up here.
Now, maybe on your beach, that 75% represents uh uh you know that this distance here is 20 feet, and that 75% over here, 15 feet, translated to you, is like enough to drown your ass, you know, especially since this is continuing and it's going to trap you up against these cliffs.
And it's going to try and climb up the cliffs here, but it won't make it just simply because the water can't support itself.
It can't really do that.
So tsunamis are deadly, they're terrible, they can drown people, they get destructive as hell, but they don't overtop cities and stuff.
Now, the problem is really that they do like going up rivers.
So if this volcano were to go uh sliding and half of it goes slide off, then we would find that all of the river basins all along the east coast of the United States, uh all along Britain, uh all of Europe, Africa, all of these river basins would potentially be conduits to funnel that mass of water up them, and that could travel some considerable distance.
So it's not unheard of to have tsunamis go a hundred miles up a river basin.
If you've got navigable water deep enough in that river, it'll it'll travel up there as far as it possibly can.
And it'll raise water up on the sides of the river, just like I was showing here, instead of hitting it in a front face, it'll just keep pushing it up on the sides of the river and can overflow and flood areas, and you get salt marshes.
We have an area here called the ghost forest.
The area I live in has been hit by a major tsunami in the 1700s that that sent a tsunami all the way across the Pacific to hit Japan, and when it hit Japan, it was like a 10-foot tsunami and it was very deadly and killed lots of people because there was just no warning at all from them because it was as a result of a volcano here.
But that uh tsunami in the 1700s on my coastline, the the back tsunami, which is what Africa and even the Canary Islands would face, that back tsunami here created what's known as the Shahalus ghost forest.
The salt water came in so far up a river area that it overtopped all of the rivers, and the salt was just laid there and it killed all these trees.
The tsunami killed the trees, and then the salt also did it, and it's just this weird salt marsh with all these dead uh old growth cedars and and spruce, giant giant damn trees.
You can go paddle your your kayak through there, and it's spooky and it's really interesting.
Um that was like maybe 15 miles in.
So there's evidence of it going up the river 15 miles.
Most of the damage is on the coast with the ghost forest.
But uh it was a considerable amount of area that that you know, hundreds of acres that got uh inundated just off this one river, and of course it hits all the rivers around.
So this is not to be taken lightly, but there's no indication that there's building pressure that would force that section of the island to move.
There's no way for anybody to know how it would crack as to where the uh chart over here is uh not accurate, all right.
So there will not be 300-foot high waves over northwest Africa.
We don't have that situation.
We won't have any overtopping.
Brazil might get uh 300 miles of uh tsunami going up the Amazon, right?
But uh it might only be uh 18 inches high or eight inches high by the time it gets there.
It will move at about 500 miles an hour, but that's about as fast as anything can move through the water from a force wave.
Um at as it approaches the 700 miles an hour where we get into 770, which in air is the um the sonic uh barrier, the sound barrier, um, it's really speed really starts degrading.
So it'll be fast, 500 miles an hour.
It travels at about the same speed as the 747 airplane.
So it'll get across there in a fair number of hours, should that occur.
Um, but and most of the east coast would indeed, along all of the river basins, and so you could expect, for instance, that the Chesapeake, you know, Washington, DC, would get hit really hard because it's got uh muddy bottoms, uh silted muddy bottoms,
so all that stuff's gonna get churned up and add to the mass, and that will um aid it to climb a lot more into the um into the inland, but it won't won't go in much beyond Washington, DC and the river deltas there, might go up a few miles, but not too many.
Uh let's see, Roanoke, um Norfolk, um Hampton Roads, all of those places are vulnerable.
Miami and those um areas would be vulnerable, but they're not going to get a giant overtopping, they're gonna get some form of a tsunami should this occur.
The tsunami again might at the point that it reaches them based on the beaches, uh, might only be you know inches, but even a foot, even 12 inches of a tsunami is going to be terrible if it goes has to go roaring through the area of um you know any infrastructure, right?
It'll it'll just do damages to bridges and all of this just because of the sheer amount of force.
The good news is that that force dissipates as it goes along, and every bump and hill and mountain, it's got to go over.
Then there's another issue here, okay.
So most people are not aware of this, but we have this situation.
If we were to look at North America, let's make Florida, Florida, and over here is Joe's house.
Uh, and here is the Chesapeake, okay.
So here would be D Washington, DC, more or less, 33rd degree parallel.
Okay, so this is the Atlantic.
I can't put that there.
I'm gonna sing it.
So uh the Canary Islands are on the other side of the Atlantic.
All right, so if this is England and that's basically Europe and France, and here we have Africa.
Okay, so in the Atlantic Ocean, there's this thing that's the mid-Atlantic ridge.
all right And it's and it's really it's it's not a mid-Atlantic ridge, it is a giant mountain range.
And this giant mountain range runs down the middle of the Atlantic Ocean and it shades over towards South America and and uh Brazil uh in moving.
Uh this mid-Atlantic ridge, if this thing pops off, it's gonna have to, it'll the force wave would travel the uh bottom of the ocean, and then it will encounter the mid-Atlantic ridge as a mountain range.
So it would encounter the foothills of that mountain range out here and would still be dealing with the foothills back over here.
And it will have to rise up and dissipate its force through all of these mountains, which are buried underneath the Atlantic Ocean as it's coming over here.
So you can assume rightly that the mid-Atlantic ridge, all of those mountains are going to absorb a lot of this force.
That force is going to travel.
So let me go back to a horizontal side view.
Alright.
So here's the top of the ocean.
Here's the mid-Atlantic Ridge mountains.
Ridge mountains.
And so that force wave is going to travel through the water thusly.
So it so over here in the Canaries, the island slips and it creates the tsunami, and the and the island only goes that far, and this part shifts out.
And so it starts creating the force wave.
And the force wave goes and travels down to the bottom of the ocean and back up and goes like this and gets starts building and gets very fast there.
It's going to start dissipating like this.
And it's going to have to go and it'll be compressed, which will create this backwards flow pressure here, which eats up some of the force, and it keeps going like this.
And then the beauty part of this is that it's going to rise up here like I was climbing up a uh a beach, but then it comes over here, and then it starts able to expand again.
And so it expands and expands.
So this effect here of the compression and the back pressure that you get, these eddy currents that are created as it goes through all these mountain ridges and valleys and shit, and then this expansion over here is going to dissipate a lot of that force.
So I would suspect that you're going to get the kind of tsunami where it starts off at 500 miles an hour and it looks like it's going to hit over there in eight or nine hours, but by the time it gets over there at eight or nine hours, its speed is reduced down to several hundreds or less, and that the force level is hugely dissipated by having gone through this exercise here of the mid-Atlantic ridge of climbing over those mountains.
They're not they're not small.
These are big-sized giant mountains just underneath the ocean.
So that also is going to aid the coast over here.
It doesn't do shit for Africa, it doesn't do anything for the Bay of Biscay in Spain and France and Portugal and all of those areas.
Okay, and Gibraltar and that sort of thing, they'll be impacted very greatly because they're so close.
They'll get a big push of it.
So they don't have there's a couple of areas of France where they have really flat sandy beaches.
Um but they're quick drop-offs, so they're going to have that dissipation thing.
So it'll be bad, but it won't be, you know, overtopping bad.
In Europe, it's going to go, it'll hit the rivers, okay.
So it'll hit um all of the uh Atlantic dumping rivers, and they'll go it'll go running up those rivers.
And so I would suspect Holland and the Flemish areas are going to be in for it because they're so low-lying.
They'll get a lot of slop over into the uh surrounding ground.
But this is on the if, this is an if it occurs.
Um, no saying it it will, and uh.
But but I bet you that if it does occur that that's how it pans out, that it's bad, but it's not this idea that you know it's gonna be a hundred and some odd feet high and it's gonna sweep Miami off of Florida and you know, and create all this new real estate or anything.
Won't won't happen out that way.
So anyway, this is wave woo.
There's a whole lot more to learn about waves.
This is a fraction.
If you go look, there's giant books on the stuff because it's studied, you know, people with that build ports for boats, people with boats.
We need to know about waves, and so it's a very studied thing.
So no, you know, don't if you see these kind of uh big map things here with giant waves, you know, that kind of thing.
So in the United Kingdom, they actually do have in some of those areas, Ireland and so on, you would have a beach that would support a 16-foot-high tsunami because of the not too steep, not too gentle, rocky, so it's not gonna dissipate with sand, all different kinds of structures there, but they're very short beaches.
So the the dissipation is gonna be fairly quickly done, and they don't have long-running rivers that and the rivers rise up.
So they're a rocky area in the United Kingdom and Ireland, and so the rivers are not dug into uh they don't dig themselves into sediment and create lots of sediment that then supports the rise of the water in the form of mud and then water on top of the mud.
So uh so we won't get that kind of thing, but they may get like 16-foot-high tsunami in on the coast of Ireland.
I could see that.
I've seen those coasts, they would certainly support a 16-foot-high tsunami if they were close enough to the source.
Um there's also the issue of the deep Irish trench.
There's a trench that's off the coast of the United Kingdom, runs all the way down um the coast of Europe, and that may actually funnel any tsunami force back up more towards the Arctic and spare the um uh the Irish and the English much real damage should this thing occur.
So um anyway, so uh this is just the the wave woo, the woo of waves, it's all discovery, and you know, not to get freaked out by it.
Um I've got an interview tomorrow.
I did one today.
I think both of them are going to be released on Friday.
I've got some more uh uh woo stuff to talk about later this week.
We're getting into some um really active periods, so I'm gonna try and keep up with it.
Uh, but in any event, so uh this is it.
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