A very large earthquake just hit Niigata, and boy, did we feel it here on the 21st floor in Ikebukuro. It measured a high six on the Japanese scale. More soon.

Okay, a few minutes have passed. It looks like it was a 6.6 on the Richter scale, centered just off the coast of Niigata.

Let me elaborate about how it felt here. I was sitting here finishing up my morning Internet ritual, when I felt the swaying start. It was a weird sensation; unlike most quakes, where the swaying can be fairly quick, the swaying here on the 21st floor was very heavy, but slow and rolling, like being on a ship at sea. Nothing shook or rattled, but doors were definitely swaying several inches. It never felt like anything was ready to break or fall, but it did for a while feel like it was threatening to do so.

I called my brother, who lives maybe ten km away, and he reported similar feelings–that this quake swayed a lot more than usual, that it felt like a Japanese “3” but not a normal one. So we definitely felt it stronger here in the tower. The power felt a bit magnified, though Sachi did correctly class it as a “3” on the J-scale. What really got exaggerated here was the length–we felt this one roll for at least a few minutes, and it continued to sway for quite some time.

Makes me wonder, will a big, local quake feel the same? Will the power be magnified but the energy converted more to swaying than to jumping? Hrmm… not something you want tot think about, with your ability to flee so restricted.

Update: Looking at an animation (click image at right) of the effects of the quake, maybe we didn’t feel the length exaggerated so much… it’s interesting to take a look at. If the animation doesn’t play in your browser, then right-click on the link here and download the target file.