Japanese quake made the earth bounce

2017-11-17 01:00:16

AN EARTHQUAKE that shook northern Japan this year with unusually violent upwards shocks may force a rethink of building design in tremor-prone regions. During a quake, the ground may shake up and down as well as from side to side, but measurements of the magnitude 6.9 Iwate-Miyagi earthquake in June (above) showed something never seen before: the upward acceleration was twice as strong as acceleration horizontally. Shin Aoi at the National Research Institute for Earth Science and Disaster Prevention in Tsukuba, Japan, who analysed data from the quake,