# Tsunami Model

26,877

10

11

## Introduction: Tsunami Model

Ever wonder what a tsunami is? Turns out tsunami follow the same physics as shallow water waves on an unimaginable scale (where the ocean, miles deep, is shallow compared to the length of the wave). Here 3 gutter segments are duct taped together to create a shallow water wave tank:

The 3 sections of gutter have different functions: the first section is where the wave is created (by sloping the gutter section full of water), the wave then propagates through the middle gutter section and runs up towards the third section which gently slopes upwards.

Disclaimers: This model does not model the deep ocean characteristics of tsunami. Wave propagation speeds are slow due to the depth of inches rather than miles.

### Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

## Step 1: Creating a Water Proof Hinge

So that one gutter can be emptied into another, there must be a flexible water proof hinge between the middle gutter section and the wave generation gutter. The duct tape is applied smoothly to the gutter edge so no creases form. Creases in the duct tape might cause leaks in the wave tank. Two lengths of duct tape are applied to each gutter edge. A 3rd length of duct tape is applied to join the two gutters. Another piece of duct tape is applied face down to prevent the duct tape from sticking to itself and to improve the seal with the gutters.

## Step 3: Attaching the Middle and Sloping Gutter Sections

The Middel and Sloping gutter sections are joined with duct tape:

This joint does not need to hinge and only a single section of duct tape needs to be applied to each side of the gutters.

## Step 4: Fill Gutter With Water

Here the gutter is filled with water. The three gutter sections should be leveled (bricks are used here) so the middle and wave generation sections are filled with water of equal depth:

## Step 5: Operation of Tsunami Model

To operate the model, the wave generation end is sloped, emptying the water into the middle section. The shallow water wave then propagates down the middle gutter section and washes up on the next sloping section of gutter.

## Recommendations

33 3.7K
19 1.7K
42 5.4K
Table Saw Class

16,230 Enrolled

## 11 Discussions

I'm not an expert but I would say that its is a fair simulation as long as you state clearly what you want to simulate.. I guess it is interesting if you want to simulate a 1 km wide shore within a 200 km wide tsunami. Border effects will be fairly integrated then. Next big problem is the vertical scale. It will not be the same in length and in depth and I don't know if it could be practical to simulate it physically (i mean materially, not calculated or computer simulated). You will have to render a scale of 3 magnitudes (from 1000m to 1m). Anyway, nice (and interesting) experimental physics.

I'm not sure that's an accurate simulation. Yes, your water is shallow, but all the energy is directed down a thin section, so there wouldn't be much energy dissipation. In fact, energy retention would be squared, since this is a 1-dimensional version of a 2-dimensional system.

I'd say the model and real-world are both 3-dimensional. But I see your point about the walls reflecting the waves.

That's pretty cool, not to mention timely. Have you any idea what scale you are working to? You could make similar-scale buildings to work out the best structures to use in tsunami-vulnerable areas, either to survive in the upper stories, or to break up the wave before it gets too far inland.

I was thinking more for school kids to have a go. That looks pretty cool, though. I wonder if anybody has ever tried to surf it...

I'm sure the order of magnitude could be easily obtained. But trying to design buildings in low lying coastal areas to withstand a storm surge (let alone a tsunami) is all but folly. Ocean catastrophes like storm surges or tsunami throw anything that floats (like an ocean liner) at anything in the way of the surging water. The tsunami model should alert people that tsunami warnings mean move to higher ground ASAP.

Dream Dragon hasjust what you are looking for. But it looks like the surfer is not in the Tsunami Basin but the Large Wave Flume (see map of The O.H. Hinsdale Wave Research Laboratory). Looks like the waves he is surfing are of the wind generated type and not a shallow water wave, which surfers might reffer to as "the soup".

Or... You could just put really tiny buildings made out of 1/64" balsa wood pieces and stapled held together with glue stick glue and watch them get destroyed.

Soliton waves, like tsunami waves follow the Linear Wave Equations very closely, so that a trough like this is a perfectly valid simulator. At very small scales there is an issue with the relative density of water and air, it's easily enough to demonstrate the principles involved.

http://oregonstate.edu/dept/ncs/photos/surf.jpg