Which Earth layer is defined as rigid and brittle?Question 31Answerasthenospheremesospheremantlelithosphere

Understanding the Question

The question asks to identify which layer of the Earth is characterized as rigid and brittle from the provided options.

Analyzing the Options

1. Asthenosphere: This layer is semi-fluid and allows for the movement of tectonic plates, thus it is not rigid.
2. Mesosphere: This term generally refers to the middle part of the mantle beneath the asthenosphere, which is more rigid but not typically described as brittle.
3. Mantle: The mantle is largely solid but behaves like a viscous fluid over geological timescales, hence is not rigid and brittle.
4. Lithosphere: This layer consists of the crust and the uppermost part of the mantle. It is characterized by being rigid and brittle, capable of fracturing to form earthquakes.

Conclusion

The correct answer is the Lithosphere, as it is the layer of the Earth that is defined as rigid and brittle.