The mega-quake of March 11, 2011 didn't arrive unheralded. On March 9, soon before lunch at 11.45 in the morning, the earth moved. A magnitude 7.3 temblor, 160kms out into the ocean, shook the city of Sendai and soon the signs were swaying in Tokyo, some 250kms further on. We were in our office as the shaking started and it was clear this was a major incident.
As the waves of an earthquake travel through the ground they spread out in a similar way to the cars in a motor race. Eventually the earthquake is no longer a single shock but a series of rolling convulsions. The longer the tremor continues, the further away the origin; if you can feel it. And if you can feel it, it will have been big. A long duration earthquake, even if it feels mild, was a major one somewhere.
After we saw the location we confirmed the staff in Tohoku were safe and then sent a short note to a business partner who's office was close to Fukushima checking everything was OK. And then we carried on. It had been a while since we'd experienced an earthquake and the subject was a hot topic of conversation over lunch. And that was all we thought of the matter. At least for the next two days.