For lake o, there are quite a few earthquakes, some getting up to. M4 which is sig for reactors (faults going through pickering and near. Lakebed crack that had not been previously recog (newly discovered faults: 6 reactors are on shakier ground than anyone thought - there (cid:272)ould (cid:271)e a m7 ea(cid:396)th(cid:395)uake, sho(cid:396)tly following that (cid:396)epo(cid:396)t . If you get 20 m7 or bigger globally, none will be in kingston area likely, so 30- 40yrs you won"t get any in kingston, but how do you look back in time: recurrence interval - associated w/ all hazard and is critical in all areas of risk, ex. Minnesota: there are 3 ways to look at recurrence interval: Look at human historical records: when there is a big quake in a region, it is recorded everywhere (records in churches, townhalls, papers), we can"t be sure how big it was, we can infer from historical records, ex.