THe 869 Jogan earthquake which was located offshore Eastern Honshu is considered the historic predecessor of the 2011 Tohoku earthquake. Many deposits along the Miyagi coast associated with the tsunami following this earthquake have been considered very similar to those from 2011. However, this does not hold up for potential deposits on the Sanriku coast which limits is size to be slightly smaller than 2011 and its effects similar to but more focus around the Sendai plain.
There is still discussion around its exact moment magnitude.
|869 Jul 09th||869 Jogan Earthquake||Honshu||8.8||C|
|1454||1454 Honshu Earthquake||Honshu||8.4||C|
|1677 Nov 04th||1677 Kanto Earthquake||Honshu||8.4||C|
|1793 Feb 17th, 14:00||1793 Miyagi Earthquake||Honshu||8.2||B|
|2011 Mar 11th, 05:46||2011 Tohoku Earthquake||Honshu||9.1||A|
|Preferred Magnitude||8.80 (8.30-9.00)|
|Quality of Evidence||C|
|2014||Namegaya & Satake (2014)||8.8 (8.6-9)|
|2013||Satake et al. (2013)||8.9 (8.8-9)|
|2012||Sugawara et al. (2012)||8.4|
This table lists some of the most relevant publications in estimating the moment magnitude of this earthquake. If you think there are other important or new publications, please get in contact.