Re: deep water = less ejecta?

[john bois <jbois@verizon.net>]

----- Original Message ----- 
From: "Tommy Tyrberg" <tommy.tyrberg@norrkoping.mail.telia.com>

> Things would be very different for a hit in really deep oceanic water,
> where an appreciable part of the depth of the transient crater would be
> in water rather than rock. In such cases even a fairly large bolide
> might not even leave a discernable crater on the bottom.

But:
"We discovered that the shallow structure of the crater was determined much 
more by what the impact site was like before impact than by the trajectory 
of the impactor," says Gulick.

My reading of this is that they infer deep water from the shallow nature of 
the crater--meaning (I think) that the water absorbed enough energy to blunt 
the force on the ocean floor.  In any case, if the crater is shallow it 
follows that less ejecta was blown out (right?); and that there was a 
greater percentage of water vapor in the mix (by the way, if there was 6.5 
times more vapor, how much _less_ rock does that mean?).
If the water/rock ratio was appreciably different this should have a 
different effect than previously believed.  For example, heat energy in 
water vapor would have a more local effect...at least versus the re-entry of 
solids globally.