The Aral Sea was a major lake of the USSR until it suffered artificial changes, which began sometime no later than the 1960s.
I am unfortunately not sure when major artificial changes began. Wikipedia says that canal construction "on a large scale" began in the 40's, but then mentioned "By 1960, between 20 and 60" cubic km of water was being diverted. So it appears the date I'm looking for is somewhere between 1940 and 1960.
Anyway, the two key figures I'm interested in are average depth and salinity. What were these in the Aral Sea before it changed? One reason I ask is I'm especially curious if it was just a smaller version of the Caspian.