A is a megathrust earthquake occurring in the Kantō region of Japan that originate from slippage in the Sagami Trough. Kantō earthquakes are thought to occur with a 200-year return period. Only two earthquakes in the Kantō region are thought to be megathrust earthquakes: 1923 Great Kantō earthquake; most common usage 1703 Genroku earthquake Other earthquakes in the Kantō region, which may or may not be due to slippage in the Sagami Trough: The Ruijū Kokushi mentions an earthquake that struck the area in 818 1855 Edo earthquake See also South Kantō earthquakes List of earthquakes in Japan Nankai megathrust earthquakes Seismicity of the Sanriku coast Tōkai earthquakes Earthquakes in Japan 1923 Great Kantō earthquake