Structure Of The Earth’s Crust

Composition of the Earth’s Crust

The Earth’s crust is the outermost layer of the Earth.

Materials:

• Composed mainly of rocks and minerals.
• Two main types of crust:
  • Continental Crust: Thicker and less dense; primarily made of granite.
  • Oceanic Crust: Thinner and denser; mainly composed of basalt.

Thickness:

• The continental crust can be about 30-50 kilometers thick.
• The oceanic crust is around 5-10 kilometers thick.

Impact of the Earth’s Crust on the Environment

The Earth’s crust is divided into large sections called tectonic plates. These plates float on the semi-fluid layer called the mantle.

• The crust shapes landscapes, forming mountains, valleys, and plains.
• Tectonic plate movements cause earthquakes and volcanic eruptions, affecting ecosystems and people.
• Crust composition impacts soil fertility and agriculture.
• Plate movements influence ocean currents and climate patterns.
• Crust changes can create or destroy habitats, affecting biodiversity.

Fun Facts

Here are some interesting facts about the Earth’s crust:

• The Earth’s crust makes up less than 1% of the Earth’s total volume!
• The oldest rocks on Earth can be found in Canada and are over 4 billion years old!
• The oceanic crust is continuously created at mid-ocean ridges and destroyed at subduction zones.
• The deepest part of the Earth’s crust ever drilled is about 7.5 miles deep, but that’s still far from reaching the mantle.

Review

Let’s quickly recap what we learned about the Earth’s crust:

• What are the two main types of Earth’s crust? Continental and Oceanic
• What layer lies beneath the Earth’s crust? Mantle
• What natural events can result from tectonic plate movement? Earthquakes
• How thick is the continental crust on average? 30-50 km