Megatsunamis: Waves over 500M high and devastation beyond the ocean

From the article: "Paradoxically, megatsunamis are not necessarily the most destructive, nor are they always synonymous with devastation."

looking at the simulation posted here, it's because the water heigh wasn't so much due to the energy that created the tsnuami but of the geographical configuration. So the nergy dissipated quite quickly and didn't do much damage

Wavelength vs height; the undersea earthquake tsunami has long wavelength but not a lot of height, but there is more water and force behind it so it's pushed further inland. These ones are like a big splash, high waves but not a lot of horizontal impulse in comparison.

500 mile high waves would be impressive.

Height without wave length is pretty useless. Normal storms come with waves way higher than most tsunami, both when approaching the shore and even more in the open sea.

You might be able to come up with some heuristics, but it won't be very useful. Your best heuristic is probably just to take the wave height and compare to the terrain elevation. Then... add a multiplier.

Numerical simulation is your friend here. And... it gets really complex. There are different simplifying assumptions made to make the calculations tenable. Where run-up is a problem, it typically happens where wave interactions or terrain create concentrations of flow and increased wave height. Roughness of the terrain matters too, not just slope.

You can probably get pretty close with off-the-shelf software just by doing a 2D HEC-RAS simulation with a terrain DEM and creative boundary conditions to simulate different wave heights, and a small time-step.

In US it also seems to be popular to use L for liter (or litre:)

They clearly meant 500 million high.

And it has to be spaced from the measure:

> The numerical value always precedes the unit and a space is always used to separate the unit from the number. Thus the value of the quantity is the product of the number and the unit. The space between the number and the unit is regarded as a multiplication sign (just as a space between units implies multiplication). The only exceptions to this rule are for the unit symbols for degree, minute and second for plane angle, °, ′ and ″, respectively, for which no space is left between the numerical value and the unit symbol.

> This rule means that the symbol °C for the degree Celsius is preceded by a space when one expresses values of Celsius temperature t.

> Even when the value of a quantity is used as an adjective, a space is left between the numerical value and the unit symbol. Only when the name of the unit is spelled out would the ordinary rules of grammar apply, so that in English a hyphen would be used to separate the number from the unit.

[1]: https://www.bipm.org/documents/20126/41483022/SI-Brochure-9....