So theres this iceberg, it grew really big over time. It may have been part of an ice-shelf that at one point didn't exist all. Once it got big a natuallly occuring event happened; be it currents, temperature or pressure -- maybe all of these. Anyway, it broke loose and floated on the current and guided by wind. Now its going north where it will melt away into the sea.
Its OK because someday it will be ice again. Happy days.