noun
Jōgan earthquake; Sanriku earthquake of 869 CE
Historical term for a major earthquake that struck the Sanriku coast in 869 CE during the Jōgan era.
貞観地震は869年に三陸沖で発生した巨大地震である。
The Jōgan earthquake was a massive earthquake that occurred off the Sanriku coast in 869.
Named after the Jōgan era (貞観, 859–877 CE) during which the earthquake occurred.