* Anonymous Metagenics Dockworker - MorganLink 3DVision Live Interview
>... [the equivalent of] 6422 kg on a cable with cross-section of 1 mm2
"megaton |ˈmegəˌtən|
noun
a unit of explosive power chiefly used for nuclear weapons, equivalent to one million tons of TNT"
Mega- is a standard SI prefix, and the use of "megaton" to denote one million tons is entirely correct. Yes, it's also true that "megaton" has a second meaning. This fact does not invalidate its other meaning. In fact, if you bother looking this up in actual dictionaries, you'll find that the normal mass definition is often listed first, and the explosive definition is listed second, for what it's worth.
In any case, I am glad I learned something new today!
But (Sid Meier's Alpha Centauri) is an American game and it could actually refer to a non-metric megaton