Q: …Gabriel and the archangel hosts moved to the place of the spiritual polarity of the planet; …Where is this?

A: The entire quote you cite reads as follows:

The circuit of the archangels then operated for the first time from Urantia. Gabriel and the archangel hosts moved to the place of the spiritual polarity of the planet; and when Gabriel gave the signal, there flashed to the first of the system mansion worlds the voice of Gabriel, saying: “By the mandate of Michael, let the dead of a Urantia dispensation rise!” Then all the survivors of the human races of Urantia who had fallen asleep since the days of Adam, and who had not already gone on to judgment, appeared in the resurrection halls of mansonia in readiness for morontia investiture. And in an instant of time the seraphim and their associates made ready to depart for the mansion worlds. Ordinarily these seraphic guardians, onetime assigned to the group custody of these surviving mortals, would have been present at the moment of their awaking in the resurrection halls of mansonia, but they were on this world itself at this time because of the necessity of Gabriel’s presence here in connection with the morontia resurrection of Jesus. (189:3.2)

I did a Search for “polarity, ” and came up with this interesting quote:

Supernaphim are limited in “spirit polarity” regarding only one phase of action, that with the Universal Father. They can work singly except when directly employing the exclusive circuits of the Father. When they are in power reception on the Father’s direct ministry, supernaphim must voluntarily associate in pairs to be able to function. Seconaphim are likewise limited and in addition must work in pairs in order to synchronize with the circuits of the Eternal Son. Seraphim can work singly as discrete and localized personalities, but they are able to encircuit only when polarized as liaison pairs. When such spirit beings are associated as pairs, the one is spoken of as complemental to the other. Complemental relationships may be transient; they are not necessarily of a permanent nature.” 26:1.16

It is from the section called “The Ministering Spirits”

The quote you cited seems to indicate that there is an actual geographical place of spiritual polarity. The quote that I gave you above seems to indicate that spiritual polarity occurs when these seraphim act as pairs in some endeavor. My initial guess is that the place of spiritual polarity is anywhere that these seraphim happen to deliberately unite in liaison to accomplish their task in accordance with the will of the Universal Father, through his Creator Son and in association with Gabriel, as in this dispensational resurrection following Jesus’ resurrection from the tomb. It is another of those instances on this planet where unusual things happen…

I hope this helps. It may not be the definitive answer, though. I will ask a couple of other long-time readers to weigh in, and if I get a better answer, I’ll pass it along.

***************

Here’s another reply from a long-time reader as well…much better detail for your question:

“The short answer is: the revelators do not tell us the location. However, we do know that every inhabited world has a “designated spiritual headquarters” (39:5.15) at which the universe broadcasts are received and from which the transport seraphim depart. This location is not only referred to as “the place of the spiritual polarity of the planet” but also “the universe energy pole of the planet” (39:5.13) and “the planetary pole of space communication” (62:7.2) via the “mind circuit of the planet” (ibid.).

In other words, this “pole” is a point of physical, mindal, and spiritual energy differential.

The revelators also do not tell us how or by whom the planetary pole is established and maintained, but logically there must be a point of differential at which to connect the planet to the cosmos. Likewise, the energy form of a supernaphim, seconaphim, or seraphim–either singly or as a liaison pair–must have a polarity (a differential) which is tuned to, and hence connected to, a particular universe circuit, in order to utilize the power of that circuit (see (26:1.16) .

And thanks again for asking this interesting question!