What are the Internet’s dependencies?

This is a fantastic starting point, though I think the model needs a lot of work. As it is an article looking at the dependencies of the internet - I would suggest that a model similar to the OSI be used, but in a deeper hierarchy than what is shown. Where the physical layer has all the hardware component dependencies listed out. But each other layer talks about the energy, config, political etc.. meta influences on them.

Take the OSI, and build a tree:

* Application

* Presentation

* Session

* Transport

* Network

* Data-Link

* Physical

--Transport Needs

--Mineral Resources

---Chemicals based on minerals

----Refined Chemicals/Compounds

-----Base Components

------Glass

------*Plastic

etc...

You wind up looking much deeper into the tree of dependency and can really start to map out this modern civilization. I would recommend THRIFTDB.com for this effort.

When you start mapping the higher layers, you start to roll things up into providers and how they are connected via physical and logical peering.

This, I feel, is a compelling and whole area of study which I think needs a lot of attention.

Just like with any system - you need to document what you have to really understand what it is you truly need.