[RegulatorCountry]

"Besides the tsunami, it would also instantly vaporize a huge volume of water into the atmosphere."

Wonder how long it would take, for such a huge volume of seawater to precipitate back to ground? I''d think that salt damage to productive agricultural lands would be a potential problem lasting long after other damage is repaired as well.

[Calvin Locke]

Now that you bring it up, wouldn't the energy of the initial impact break apart some quanity of H2O, causing additional
burning and other chemical reactions, such making HCl, with the additional heat bringing acid rain higher in to the atmosphere?

Not to discount the salts, but at some point, the vaporization would tend to leave behind the salts.

So, given the prevailing winds, the damage might be greatest immediately downwind of an impact. That's to say a Pacific
strike off of CA would do a number on their agricultural lands.

And while salt isn't effective below a certain temperature for melting ice, there would be the potential for increased
flooding from mountain snow packs too.