Here's a breakdown of Earth's layers:
* Crust: The outermost layer, ranging from 5-70 km thick.
* Upper Mantle: Extends from the base of the crust to about 410 km depth. This is where the 100 km mark lies.
* Transition Zone: This zone is between 410 km and 660 km.
* Lower Mantle: Extends from 660 km to 2,890 km depth.
* Outer Core: Liquid iron and nickel from 2,890 km to 5,150 km depth.
* Inner Core: Solid iron and nickel from 5,150 km to the center of the Earth (about 6,371 km depth).
