Not unlike St. Paul's Mishna reference (in the Holy epistle to the Corinthians) to the stone that followed post-exodus Israel around the desert en-route to the promised land, Tartarus has a root in tradition. In the book of Enoch we find a story wherein Angels who fell were placed in a Tartarus-esque “place”, out of harm's way. Whether Tartarus or this dark place wherein the Angels were cast and bound was revealed to Israel post or prior to the use and presuppositions of words like, “Abyss” or “Tartarus” or “Hades” or “Sheol” or “Abbadon”, I do not know.
The way I have approached the reality of the afterlife and the various Orthodox explanations is to accept what seems contradictory insofar as it does not contradict. What I mean here is that on some levels most of the Orthodox teachings on this subject do agree with one another up to a certain point.
Where they depart is when the teachings appear to us as etiological necessity. For example, if I say that Gehenna is a “place” then my mind as much as it is able to grasp is going to cling to geographic illustrations and references in order to keep its compass from spinning. Some fellow Orthodox brother stops by and says that Gehenna is a “state of being”, my brain is going to puff up and say, “that is contradictory and both of us can't be right.”
Another example: we often hear or read the word, “Hades” being called, “Hell” and as I understand, “hell”, Hades is not “hell” in the sense that the second death is a truer “hell” and yet at the same time it is appropriate to call Hades, “hell”. We certainly can receive a foretaste of that second death in Hades even if the Lake of Fire isn't “in” Hades. Again, we earthen vessels have to resort to cave paintings to explain the unexplainable because all we can write with is a pile of dust. Abraham's Bosom is also said to be in Hades. Go figure.
It is also appropriate to call Hades, “paradise”. Abraham's Bosom was (and still is!) considered to be “in” Hades. Hades is Sheol. Sheol was said to be divided into different compartments. Depending on the tradition, some Jewish sects or movements believed Sheol to be divided into two, four, twelve different sections. Our Lord speaks about there being at least two, however we are to understand “two”, I don't know.
The kicker is when we begin to argue within ourselves whether we should think of these “places” as “states” or “geographical” realities. If holiness will improve our Noetic GPS then we would probably have little need for such arguments and become that which we seek to know the answer to. What need I of heaven when I become heaven, is one of my favorite quotes and I have forgotten who said it but I know that such a gem is a pile of dust that can only shine when tested by the fire. In other words, I am pretty sure that it was a canonized Saint who was inspired to say such a thing.
One glaring oversight that is common is the reality that Our Lord called Sheol, “Hades”. In more ways than one, that reality says much. He did not come for the gentile but for the Jew and yet the Jews were Hellenized Jews. I do not think that there is Irony in heaven but that reality still strikes awe in me.
We see but dimly. Our salvation is our aim. Much else will often cause the arrow to miss the mark. Communion with God is the mark. Knowing or satiating our curiosity about the particulars of the afterlife must be salvific. Regardless of the explanations of these types of subjects, the reality is that, either way, we will find out the answer – even if we never ask the question.