There ain't no studying "The Apocalypse" since it is supposed to be the end of the world. When we say "the end of the world" we mean the end of humanity. Humanity may well destroy itself, but the world, the planet, will continue without us as it has continued without many, many species that have come and gone.
Eschatologist.
a person who studies people but not an psychologist
A person who studies genealogies is a genealogist.
A person who studies organisms is called a biologist.
a person that studies gems is called a gemologist.
what do you call somebody who studies snails.
A person who studies poisons is called a toxicologist.
A person who studies the earth is called a geologist.
A person who studies birds is called an ornithologist.
A person who studies birds is called an Ornitholoigst
A person who studies the mind is called a psychologist.
A person who studies lichens is called a lichenologist.