Re: Asteroid explosion energy distribution.

Allen Roy (
Fri, 19 Mar 1999 16:34:48 -0700

> From: Massie <>
> Have you seen the astreroid crater in Arizona.

One of the advantages to being free to offer part time bus driving to the
local public school is to drive the kids on field trips. Today we just
poped over to Meteor Crater again. So yes, I have seen Meteor Crater.

> You see this and then
> tell me that the majority of the energy is absorbed in the atmospheric
> shock wave.

Perhaps the two examples I gave confused you. The bomb at Hiroshima and
the Tunguska asteroid both exploded in the air. Thus shock waves in the
air were the primary used of the energy generated these explosions. The
point of the examples was to show that atomic and asteroid explosions do
not primarily generate heat, but that most of the energy is channeled into
shock waves.

When the asteroid is large enought to reach the ground, then you also have
shock waves in water (mega-tsunami) and the P and S waves in the ground

> The statement that the energy is mainly dissapated in heat is in some
> since absolutely true because all energy eventually ends up in some low
> grade heat.

This is true, but atomic and asteroid explosions generate mostly
destructive shock waves and some heat.

> But this is not the point. Let see if we can list the channels:
> Atmospheric shock waves.
> Water waves and ground waves (acoustic as well(shock waves are a form of
acoustic waves.)
> Heating of the area struck (ground or water).
> Ejecting of fragments (they carry kinetic energy).

If you will notice, this is the same list I made:
> > Thus we can conclude that the major part of the energy of the asteroids
> > will be disipated by shock waves in the air, by evaporation and
> > mega-tsunami in water, and by rocks and dust thrown into the atmosphere
> > along with P and S waves in the ground. There will be some primary
> > generated by the explosion. Secondary heat will also be generated by
> > following fires, volcanism and plate tectonics.

> What I think is howeve the real issue is that so much of this is
> supposed to happen is such a very short time. Any of these objects
> alone could shove the earth into a quasistable climatic state that is
> way off of the equilibrium we enjoy. I am not just talking about some
> extra rain storms but something a lot more catastrophic, such as the
> proposed nuclear winter. Thus, the real impact may be difficult to gage
> but the real problem is the theory that all of these super energetic
> events are being postulated in 40 days or so without any justification
> based on physical evidence or analysis of how this tremendous amount of
> energy would impact the planets stability or the destructive events such
> as shock waves, global fires, tsumanis, enourmous earthquakes and the
> like.

I agree. From what I have read so far, there is alot of disagreement on
just how destructive these impacts would be. Even one as large as Chixilub
may not initiate global climatic catastrophe by itself. I tend to think
that many of the proposals are exagerated to try to account for the
extinction of the dinosaurs.

Most of the craters are very small. From an online list, I notice that
only 6 or 7 craters are 100 km or larger. The average is likely about 20
km across.

The physical evidence is the craters in the strata designated as flood
strata. The analysis is in progress. This analysis is expected to show
that enough energy was transferred to the planet to cause a catastrophe,
but not so much so that the Ark and those inside could not survive.