It had an epicenter close to Edo (now Tokyo), causing considerable damage in the Kantō region from the shaking and subsequent fires, with a death toll of 7,000–10,000 people and destroyed around 14,000 buildings.

[5] The earthquake's destruction and associated death toll were especially great for the time, as Ansei Edo was composed largely of plaster-and-tile structures that were resistant to fires but prone to tremors.

This lack of structural preparation, combined with the fact that most of the well-populated areas of Edo were built on former wetlands artificially filled in with unstable alluvial soil, left the city undefended from the massive force of the Ansei quake.

In addition to loans for reconstruction funds and expenses for restoration projects to the domains affected by the Ansei Tokai and Nankai earthquakes of the previous year, the Edo Shogunate was forced to spend a large amount of money on support for the hatamoto and gokenjin and disaster victims of the earthquake and for the reconstruction of Edo City, aggravating the financial deterioration at the end of the Tokugawa shogunate.

The significance being that earthquakes at the time were popularly attributed to the thrashing about of a mythological catfish under the earth, normally kept under control by the deity Kashima using a large rock.

Combining the effects of these disasters with a major cholera outbreak killing over 100,000 people, a fire at Edo Castle, and the 1858 Hietsu earthquake, the Ansei era was one of quite catastrophic upheaval.