Holy Fuck indeed, sir. Holy Fuck indeed.

About 7 seconds for the shock wave to hit so, at the speed of sound, the blast was a little over 2km away?

I jumped in my seat even though I caught a glimpse of the shockwave coming.

As it takes place in a desert / arid climate with (by the looks) higher average temperature (probably around 30° C), the distance would be around 2.6km.

Not sure about the military but we don't use km in normal life in the UK. In theory we're decimalised, and we use decimal currency and weights and volumes, for the most part. We do still measure our body weight in lbs, our height in feet and inches and the speed of our cars in mph. Distance on the road is in miles too, and gas mileage is mpg. Milk is sold in pints, as is beer. Timber is in inch dimensions (2x4 and so on) and usually in 8ft lengths. If it's sold in decimal measures it's a decimalised imperial measure, so instead of buying an 4 board you'll get a 2440mm x 1220mm.

We do use centigrade rather than fahrenheit. And fizzy drinks are sold by the litre. Come to think about it I really don't know why people think we're decimalised!

The US Military uses meters and kilometers.

What did you think something like "we are 2 klicks south of your position" meant?

http://usmilitary.about.com/od/theorderlyroom/f/faqklickdef.htm