The Chicxulub Megatsunami

[Jmanm]

Some sites suggest the height could have been 4-5km. I want to confirm that this is the initial splash height? And what was the height that would reach land several 100km's away?

 

Some sources say the weater depth of impact was only a few hundred metres deep, would this mean the wave would have been not very high when it gets to a distant coast?

 

Would the height and amount of coastal inidating be alot worse if the impact was in deep ocean rather than shallow sea?

 

Finally, if the comet hit in deep ocean would that redcuce the amount of damage it did to the the whole world & life?

 

thanks

[pavelcherepan]

Some sites suggest the height could have been 4-5km. I want to confirm that this is the initial splash height?

 

What do you mean by "splash height"? At the point of impact and even kilometers away from it the temperature would be so extreme that water would instantly evaporate, hence there'd be no splash. Rather than tsunami being a result of the asteroid splashing into the ocean like a stone creates waves when you throw it in water, it was a result of the seismic event that the impact created.

 

 

 

And what was the height that would reach land several 100km's away?

 

I would say that the number of 5 kilometres refers to the height of tsunami as it hits the shore. Tsunamis are created by a vertical displacement of Earth's crush (also landslides too, but that's not important) so in order to have a 5km tsunami wave somewhere in the open ocean not too far from where it's been created, the vertical movement of the crust would have to be around the same amount - 5 kilometres or more. Normally in the open ocean tsunami waves are only some tens of centimetres high and generally very hard to notice. On the other hand, when such wave approaches the shore the sloping of the sea floor causes it to rise up and that's when you'd have all the huge 50, 250, 500-m high waves.

 

There's also an interesting simulation video on Youtube that shows that whatever happened it's unlikely that the height of the tsunami was more than a 100m. https://www.youtube.com/watch?v=Dcp0JhwNgmE

Edited November 2, 2015 by pavelcherepan

[billiards]

The speed of the wave (tsunami) depends strongly on the water depth: shallow water leads to slower wave propagation. The slowing down of the wave as it reaches the shore causes the wavelength to shorten and to conserve energy the amplitude of the wave increases. This is why tsunamis are so high at the shore but barely noticable in the open ocean.