Difference Between Inner Core and Outer Core of the Earth

Main Difference

The main difference between the inner core and outer core of the earth is that inner core of the earth is the innermost layer of our planet, whereas outer core is the layer that surrounds the inner core.

Inner Core vs. Outer Core

Our earth is composed of four layers, i.e., the crust, mantle, outer core, and the inner core. The topmost layer is crust, which is followed by the thickest layer known as the mantle. The innermost layer is known as core and is further divided into two layers, i.e., the inner core and the outer core. The inner core is made up of a solid ball of iron and nickel due to high pressure in it whereas, the outer core is made up of liquid iron and nickel. The inner core has a radius of 1,220 kilometers or 768 miles, whereas the radius of the outer core is almost 2,300 kilometers or 1,400 miles. The temperature of the inner core is 5,400 degrees Celsius, on the other side, the temperature of the outer core is about 4,000 to 8,000 K (6,740 – 13,940 degrees F or 3,730-7,730 degrees C).

Comparison Chart

Inner Core of the EarthOuter Core of the Earth
The innermost part or layer of the earth is known as the inner core of the earth.The layer that surrounds the inner core is known as the outer core of the earth.
Composition
The inner core of the earth is a solid mass of iron and nickel and some light elements, e.g., oxygen, sulfur, and silicon, etc.The outer coreof the earth is a layer of iron and nickel.
Nature
The nature of the inner core of the earth is solid due to high pressure on it.The outer core of the earth has a liquid nature.
Location
The inner core is located 6,371 kilometers (3,958 miles) deep beneath the surface.The outer core of the earth is located 2,890 kilometers (1,400 miles) beneath the surface of the Earth.
Temperature
The temperature of the inner core of is estimated to be about 5,400 degrees Celsius or 9,800 degrees Fahrenheit.The temperature of the outer core is 4,000 to 8,000 K (6,740-13,940 degrees F or 3,730 – 7,730 degrees C).
Radius
Earth’s inner core has a radius of about 1,220 kilometers or 768 miles.The radius of the outer core of the earth is approximately 2,300 kilometers or 1,400 miles thick.

What is the Inner Core of the Earth?

The inner core is the innermost geologic layer of the Earth. Seismologist Inge Lehmann was the first one who discovered the solid inner core surrounded by a liquid outer core. There are no samples for the direct measurement of Earth’s core so, the information about it mostly comes from analysis of and the magnetic field and seismic waves. This core of the earth is made up of a solid ball of iron and nickel and some light elements, e.g., oxygen, sulfur, and silicon, etc. It is a widely-accepted that the inner core is gradually expanding because the liquid outer core cools down and solidifies at the place where the two layers meet. The inner core is located 6,371 kilometers (3,958 miles) deep beneath the surface, and its temperature is estimated to be about 5,400 degrees Celsius or 9,800 degrees Fahrenheit. The radius of the inner core is about 1,220 kilometers or 768 miles.

What is the Outer Core of the Earth?

The layer of earth that surrounds the inner core of the earth is known as the outer core. It is a liquid layer made up of iron and nickel. The constant churning of liquid iron present in the outer core creates a magnetic and electric field. This process is called the geodynamo, and it is responsible for the magnetic field that surrounds our planet. The outer core of the earth is located 2,890 kilometers (1,400 miles) beneath the surface of the Earth. The temperature of the outer core is 4,000 to 8,000 K. The hottest region of this core of the earth is about 3,730-7,730 degrees Celsius or 6,740-13,940 degrees Fahrenheit. It has a radius of about 2,300 kilometers or 1,400 miles thick.

Key Differences

  1. The innermost part or layer of the earth is called as the inner core of the earth, whereas the layer that surrounds the inner core is known as the outer core of the earth.
  2. The earth’s inner core has a solid nature due to high pressure on it while the outer core of the earth is liquid in nature.
  3. The inner core of the earth is a solid mass of iron and nickel and some light elements, e.g., e.g., oxygen, sulfur, and silicon, etc. on the other hand, the outer core of the earth is formed by a liquid layer of iron and nickel.
  4. The radius of the inner core is about 1,220 kilometers or 768 miles conversely the radius of the outer core of the earth is approximately 2,300 kilometers or 1,400 miles thick.
  5. The inner core is located 6,371 kilometers (3,958 miles) deep beneath the surface on the flip side, the outer core of the earth is located 2,890 kilometers (1,400 miles) beneath the surface of the Earth.
  6. The temperature of the inner core is 5,400 degrees Celsius or 9,800 degrees Fahrenheit, on the other side, the temperature of the outer core is from 4,000 to 8,000 K (6,740 – 13,940 degrees F or 3,730-7,730 degrees C).

Comparison Video

YouTube video

Conclusion

Above discussion clarifies that the inner core is the innermost layer of earth that is solid in nature, whereas outer core surrounds the inner core and it is a liquid layer.

Author:

Aimie Carlson

Aimie Carlson is an English language enthusiast who loves writing and has a master degree in English literature. Follow her on Twitter at @AimieCarlson

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