Hi Matt,
Loaded questions there. I'm not sure if Antarctica is Atlantis, but something huge is going on there. It's a lot to type up and answer, we could create two book volumes simply off of your questions.
I suggest you look in to the Cosmic Disclosure series on gaia.com with Corey Goode and David Wilcock.
Start with the first episode of season 1 and work your way through 100+ episodes already disclosed. All your questions are covered there, plus much, much more for a fuller, broader understanding:
https://www.gaia.com/video/message-humankind?fullplayer=feature
Some additional info:
1.) http://sitsshow.blogspot.co.za/2017/03/david-wilcock-antarctic-atlantis.html
2.) http://inteldinarchronicles.blogspot.co.za/2017/03/theres-truth-to-ouch-sitrep-by-mayan.html
Loads of info to work through there, hope it sheds some light on your questions.
I am another yourself
Mayan Guy