1. Crust (Outermost Layer):
* Temperature range: 0°C to 1,170°C (32°F to 2,138°F)
* Average temperature: Around 20°C (68°F) on the surface, increasing with depth.
2. Upper Mantle:
* Temperature range: 1,170°C to 1,600°C (2,138°F to 2,912°F)
* Key features:
* Contains the asthenosphere, a partially molten layer.
* Heat is generated by radioactive decay.
3. Lower Mantle:
* Temperature range: 1,600°C to 3,700°C (2,912°F to 6,692°F)
* Key features:
* The solid mantle, but still very hot.
* Pressure increases significantly, keeping the rock solid despite the high temperature.
4. Outer Core:
* Temperature range: 3,700°C to 5,500°C (6,692°F to 9,932°F)
* Key features:
* Liquid iron and nickel.
* Responsible for Earth's magnetic field.
5. Inner Core:
* Temperature range: 5,500°C to 6,800°C (9,932°F to 12,232°F)
* Key features:
* Solid iron and nickel due to immense pressure.
* Hottest part of the Earth.
Why does temperature increase with depth?
* Radioactive decay: Naturally occurring radioactive elements like uranium, thorium, and potassium decay, releasing heat.
* Residual heat from Earth's formation: The Earth formed through the accretion of smaller bodies, releasing a vast amount of gravitational energy that is still radiating outward.
* Pressure: As you move deeper into the Earth, the weight of overlying layers creates immense pressure, compressing the materials and generating heat.
Note: These temperatures are estimations, and it's difficult to measure them directly. Scientists use indirect methods, such as studying seismic waves, to determine the temperatures within the Earth.
