system
A chat on 4chan
human
From what I gather this looks to be the layout/border of an old city. For context pic related is a picture of south Florida and the way it abuts up to the everglades to the west
gpt
Back to Alaska, here's a zoomed in portion of that northern coastline where you can clearly see the abnormal terrain being protected by those man made coastlines
human
The only other place in the world I was able to find formations like this was in northern Russia along the coastline which you guessed it is also manmade
gpt
Zoomed in version of an area along the Russian coast
human
Last picture....in the pink is that portion of Alaska and in red is the portion of Russia where these same manmade coastlines and strange terraformations occur.

In my opinion these were two population centers of a time long forgotten and which ended in cataclysmic armageddon. 

This is all I got for the topic and I'm trying to learn more, but I can't find anything regarding who/what/why/when/how these landscapes ended up the way they do. Let me know what you think /x/ even if you trash the theory and give me a perfectly plausible reason, like I said I'm trying to learn more about this
gpt
Cataclysmic Armageddon brought on by a hot war* I should add