A part of an email from Leonardo "Nano" Seeber, who was in Tokyo for, of all things, a tsunami conference (I linked to his CNN commentary on a thread below). Usually I would not repost an email but see no harm here:
Chris

The most astonishing thing about it was the continuous barrage of aftershocks, spanning a wide range of distances and thus of frequencies. The shaking was strong, but I remember M5 in Landers or Italy that hurt the knees. The M8.9 was more like riding a truck at high speed over a rough road: no hammer strikes.