Who is Jason from Subterranean and what is their importance?

Jason Carter is Ashley's eleven-year-old son. She insists that he accompany the expedition to the army base in Antarctica, and he proves to be a crucial character who is resourceful and very smart, despite the fact that he is only eleven. Jason witnesses many of the deaths in the story, and yet he continues to use his brain to try and figure out a way out of the different situations that he finds himself in.