I would suspect that the imparted energy would need to be much greater

than a mere 10 Mtons to reach and impart heating energy down to the

core-mantle boundary.

The largest of Impact craters are rarely greater that 250 KM in diameter, so

the energy and depth of deformation of materials could not be much deeper

than the radius of the impact crater.

A way you could test this is to make a test pit of alternating layers of sand and

thick aluminum foil in horizontal layers.

Firing a high velocity rifle bullet into the pit vertically, then vacuum out the

sand layer by layer and measure the deformation of the aluminum foil

layers.

When you can no longer detect deformation of the foil layers, it will tell

you how far the energy penetrates through the sand.

The impact craters of the diameter smaller than 30 km doesn´t contain the residual impact melt. Only the craters with the diameter bigger than 100 km contain the in-situ melted rocks (pseudotachylites). The area of such veins is comparable with the crater diameter. Therefore, we can suppose that the depth distribution of such melted rocks can be of the same diameter as on the surface.

On the other hand, we can observe sometimes the volcano on the opposite side of the impact crater. We can suppose the melting of rocks due to higher dissipation of the energy of friction during the "meeting" of the S-waves (or R- or L-waves) in one point on the opposite side of the Earth (Deccan traps). The same situation is on the Mars, where the biggest volcanoes are on the opposite side of the impact craters (Olympus Mons).

But, the energy density at the core/mantle boundary would be smaller than on the opposite side of the globe. Therefore, I don´t suppose that the dissipation of the energy of S-waves at the core/mantle boundary would be higher than on the surface. I suppose that the increasing of the energy would be measurable, but not only at the area directly below the impact crater but everywhere on the boundary (the difference between 2900 km and 6000 km is not essential).

With higher temperature seismic waves tend to have larger attenuation and this was used for seismic tomography models of temperature distribution (Karato S.). The larger the attenuation, the larger the temperature. When considering the ray theory (Cerveny V.) it assumes that every interface serves not only as a place where you can switch from one type of the seismic wave into another, but also this place is where you dump certain amount of energy. Then every interface should serve as a heat source during seismic wave propagation. Or not?

The closest core-mantle boundary is 2900 km down.

The energy would fan out like a trumpet or french horn,

or a tuba, and would dissipate through the rock.

Yes, you are completely right. Each of interfaces is a heat source. According to M.L. Keith (1993), the mantle/crust boundary and upper/lower mantle boundary are therefore the heat source. The radionuclides are not the main heat source.

OK, now you have 10 Mtons surface explosion. How would one model the temperature increase at the core mantle boundary if there are no other interfaces above this boundary and all of the above would be considered to have mantle properties as function of depth (T, P)?

If you can access the cover of the March 2000 Issue of SCIENTIFIC

AMERICAN Magazine you will see the differential " layered " motions

inside the Earth. The differential motions create a layered plastic

deformation and " Westward Mantle Flow " of the materials.

A significant portion of the heating should be associated with friction.

The core of the Earth makes one additional revolution every 400 years

inside the Earth compared to the number of revolutions made by the

Mantle in that same time period.

The change then would be about 1 GRAD per year ( about 1.1 degree

per year )

The advance would equate to a little over one arc second per day more

core rotation than Mantle rotation. This should generate some heat.

The problem with the heat, is lack of a sufficient gradient to get rid

of the heat build up 2900 km and more down inside the Earth.

I provides an understanding as to why larger and more massive planets

than Earth convert to becoming gas giants. It also gives a reasonable

concept as to why the Earth formed and maintained a life sustaining

gas and water envelope that has lasted more than 630 million years, which has

been long enough to develop and maintain conditions suitable for larger

life forms to exist.

Earth's surface conditions benefit from the planets inability to get rid

of excess heat easily.

In case of photon radiation there is a complex part of magnetic permeability and permittivity that define how much energy is lost on the interface. What would be equivalent of this for seismic waves? Phase shifted S waves?