Question map
Which of the following statements is/are correct? 1. The Earth’s crust is brittle in nature. 2. The mean thickness of the oceanic crust is 15 km, whereas that of the continental crust is around 30 km. Select the correct answer using the code given below.
Explanation
The Earth's crust is the outermost solid layer and is characterized as being brittle in nature [1]. This brittleness allows for the occurrence of earthquakes when stress is applied. Regarding thickness, the crust varies significantly between oceanic and continental regions. The mean thickness of the oceanic crust is approximately 5 km to 7 km [1], while the continental crust has a mean thickness of around 30 km [1]. Some sources indicate the oceanic crust can range up to 10 km or 30 km in specific contexts [2][3], but the standard mean value cited in core geographical texts is 5 km [1]. Therefore, statement 1 is correct as the crust is brittle. Statement 2 is incorrect because the mean thickness of the oceanic crust is 5 km, not 15 km, although the continental crust figure of 30 km is accurate [1].
Sources
- [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 3: Interior of the Earth > The Crust > p. 22
- [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 4: Earths Interior > The Crust > p. 52
- [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 8: Convergent Boundary > Volcanism and Earthquakes in Continent-Continent Convergence > p. 123