Earth's Dynamic Crust

Front

What is the asthenosphere and its role in tectonic plate movement?

Back

The asthenosphere is a semi-fluid layer of the Earth's mantle located beneath the lithosphere. It allows for the movement of tectonic plates due to convection currents.

Front

What is convection in the context of the Earth's mantle?

Back

Convection in the Earth's mantle refers to the process where hot, less dense material rises, while cooler, denser material sinks, creating a cycle that drives plate tectonics.

Front

What are the characteristics of oceanic crust compared to continental crust?

Back

Oceanic crust is thinner, denser, and primarily composed of mafic igneous rocks, while continental crust is thicker, less dense, and composed of felsic rocks.

Front

What happens when two tectonic plates collide?

Back

When two tectonic plates collide, one plate may subduct beneath the other, leading to geological features such as mountains, earthquakes, and volcanic activity.

Front

What is subduction and why does it occur?

Back

Subduction is the process where one tectonic plate moves under another and sinks into the mantle due to differences in density, typically involving oceanic crust subducting beneath continental crust.

Front

What are P-waves and S-waves in seismic activity?

Back

P-waves (primary waves) are compressional waves that can travel through solids and liquids, while S-waves (secondary waves) are shear waves that can only travel through solids.

Front

Why do S-waves not travel through the outer core?

Back

S-waves cannot travel through the outer core because it is in a liquid state, which does not support shear stress.

Front

What is the significance of the boundary between the Earth's mantle and outer core?

Back

The boundary between the Earth's mantle and outer core is significant because it marks a transition from solid to liquid, affecting seismic wave propagation and Earth's magnetic field.

Front

What are the inferred pressure and temperature at the boundary of the Earth's stiffer mantle and outer core?

Back

At the boundary of the Earth's stiffer mantle and outer core, the inferred pressure is approximately 1.5 million atmospheres and the temperature is around 4950°C.

Front

How do seismic waves help us understand the Earth's interior?

Back

Seismic waves provide information about the Earth's interior by revealing the properties of different layers based on their speed and behavior as they travel through various materials.