Help me understand the story/plot timeline

[meatnub]

I'm trying to understand the timelines in the story and would appreciate some help!

I am trying to get the whole picture from when the WWI soldiers first showed up, to when the scientists showed up, and then the Caste. And then Phillip's father.

Did everyone show up at the caves at once? Or was it WWI soldiers first... and then they all died?

How much of the caves did the WWI soldiers excavate?

Did other miners and scientists showed up later?

What about the people of Greenland? I remember something mentioned about them and their belief in Gods. There was a note about that.

Did the scientists and Caste show up together?