I have one question:
Does a part of the matter of the asteroid would be converted into energy (light / heat; by E=mc²; "nuclear fusion?") in a event like this?
I think it's possible at such a high pressure it is in a event like this isn't it...?
I'm not a nuclear expert, it's just a question...
I'd have to check on the pressures and temperatures, but my gut sense is fusion was a so-tiny-as-to-be-negligible part of the energy release. Chemical heat release was possible but also probably quite small.
The vast amount of energy dissipated as friction and pressure waves came from kinetic and potential energy possessed by the meteor just as it hit the upper atmosphere.
Kinetic Energy (K.E.) = (1/2)*mass*(velocity^2)
Potential Energy (P.E.) = mass*gravity*height
mass = 10,000 tonnes or 10^7 kg
velocity = 64,000 km/hr or 17,800 m/s
height = 100 km (Karman line, estimate of upper atmosphere limit)
K.E. = (1/2)*(10^7 kg)*((17,800 m/s)^2) = 1.6*10^15 Joules (~380 kilotons)
P.E. = (10^7 kg)*(9.81 m/s^2)*100,000 m = 9.8*10^12 Joules (~2.3 kilotons)
There is a 500 kiloton number floating around with relation to this meteor - I don't know how that particular number was determined but you see that the above calculations provide the same order of magnitude.