2011 Tōhoku earthquake and tsunami additional power, because TEP's power plants were also damaged in the earthquake. Kansai Electric Power Company (Kepco) cannot share electricity, because its system operates at 60 hertz, whereas TEPCO and TEP operate their systems at 50 hertz; this is due to early industrial and infrastructure development in the 1880s that left Japan without a unified national power grid. Two substations, one in Shizuoka Prefecture and one in Nagano Prefecture, were able to convert between frequencies and transfer electricity from Kansai to Kanto and Tōhoku, but their capacity to do so is limited to 1 GW. With the damage to so
1923 Great Kantō earthquake 1923 Great Kantō earthquake The struck the Kantō Plain on the Japanese main island of Honshū at 11:58:44 JST (02:58:44 UTC) on Saturday, September 1, 1923. Varied accounts indicate the duration of the earthquake was between four and ten minutes. The earthquake had a magnitude of 7.9 on the moment magnitude scale (), with its focus deep beneath Izu Ōshima Island in Sagami Bay. The cause was a rupture of part of the convergent boundary where the Philippine Sea Plate is subducting beneath the Okhotsk Plate along the line of the Sagami Trough. Massacres such as the Kantō Massacre were