I find measures of ground movement good for visualising what happened and how violent it must have been. Not that this is helpful sometimes with silent quakes generating a fair amount to movement (via GPS measure) in New Zealand lately. The recent 7.8 caused up to 10m of fault slip and 5.5m of uplift. The changes are truely colossal.
To confuse things, Japan has its own scale which has similar numbers to the Richter scale but with different meaning.