Science Olympiad Dynamic Planet Practice Test

What is the average density of the continental crust?

1. 1.3 g/cm3

2. 2.7 g/cm3

3. 3.5 g/cm3

4. 4.0 g/cm3

The correct answer is: 2.7 g/cm3

The average density of the continental crust is approximately 2.7 g/cm³, which reflects its composition primarily made up of various types of rocks, including granite and sedimentary formations. Continental crust is less dense than oceanic crust, which averages about 3.0 g/cm³. The composition of the continental crust includes significant amounts of lighter elements like silicon, aluminum, and oxygen, contributing to its lower density compared to the denser, iron-rich components found in the mantle and oceanic crust. Therefore, 2.7 g/cm³ serves as a representative value for the average density, taking into account the diverse rock types and structures found in continental regions. Understanding the average density of the continental crust is crucial in geophysical studies, including tectonic plate interactions and isostatic adjustments, which are linked to processes like mountain building and erosion.