Thanks for posting this. This concept should probably be out there at least just for consideration. I believe I may have given the idea some brief consideration myself when reconciling the missing peninsula, but quickly discarded it because there is little basis for it aside from an ancient map that might
be a genuine depiction of a deglaciated Antarctica sans Palmer Peninsula.
Given that Schöner did scale an ancient map to his globes of 1515 and 1520, it is almost unthinkable that he abandoned reasoned cartographic methods similarly practiced and very clearly acknowledged by Piri Reis and suddenly resorted to inventing
a landmass for his globe of 1524. The first two are clearly ancient maps of the ancient world. The latter, if based similarly on world landmasses, finds Antarctica as the only landmass with any similarity and the similarities are indeed striking.
Yet as you have stated, the omission of the Palmer Peninsula is clearly an enormous exception in an otherwise accurate portrayal.
I personally do believe that cataclysmic events shaped a large portion of Earth's current geology, and in that light geological changes have occurred rather rapidly in contrast to the slow gradual view endorsed by uniformitarians. But as flawed as I believe the uniformitarian theory of plate tectonics is, there are certain elements upon which it is founded that are very solidly grounded and within either the current or what I believe will be the new paradigm I can see no way to reconcile the event you are proposing. I can think of no viable instance where the mountainous Palmer Peninsula could be completely submerged while the remainder of the Antarctic continent remained virtually at the same sea level that it does today.
So based on this, I prioritize the list of possibilities a little a differently:
- The map does not depict ancient Antarctica. (This may be your number 1 as well.)
- Palmer Peninsula is actually an island when the continent is deglaciated and was intentionally omitted perhaps due to its lack of importance in the eyes of the people that charted it and/or due to the possibility that inclusion of the lengthy island within the constraints of the medium used—likely an animal skin—would have forced the cartographer to shrink Western and Eastern Antarctica and along with them reduce much of the continent's more intricate details.
- The peninsula was submerged, but breached the surface—by nearly 2 miles in places mind you—after the continent was charted due to an undefined cataclysm.
Basically, weighting the scale with current consensus and my findings, I give option 1 an above 50% chance of probability, option 2 has a sub 50% placing and option 3 garners 0%.
Just my opinion, and yet I personally lean toward option 2 with lesser odds. So like you I am relying on pure speculation as well, but favor going a slightly different direction. I could warm up to option 3, but I would need to see a more detailed theory with sufficient evidence from a geological standpoint before I would be willing to do so.
BTW, sorry for the late response. Things have been a little bit hectic around here as of late and I wanted to have time enough available to compose an adequate reply.