Earth Science: Crust and Seismic Waves

Questions and Answers

Why are no P-waves or S-waves received in the shadow zone?

S-waves cannot pass through liquid

P-waves are refracted and S-waves are absorbed by Earth's outer core

P-waves are reflected at the surface

Both A and C (correct)

Compared to Earth's continental crust, Earth's oceanic crust is?

thinner and more dense

The basaltic bedrock of the oceanic crust is classified as?

mafic, with a density of 3.0 g/cm3

What is the inferred temperature at the interface between the stiffer mantle and the asthenosphere?

2500C Signup and view all the answers

Which combination of temperature and pressure is inferred to occur within Earth's stiffer mantle?

3500C and 0.4 million atmospheres Signup and view all the answers

Most inferences about the characteristics of Earth's mantle and core are based on?

the behavior of seismic waves in Earth's interior Signup and view all the answers

Evidence of crustal subsidence is provided by?

shallow-water fossils beneath the deep ocean Signup and view all the answers

Which process was primarily responsible for forming the hills?

faulting Signup and view all the answers

What takes 8 minutes and 20 seconds?

the time for sunlight to reach Earth Signup and view all the answers

Study Notes

Seismic Waves and Earth's Structure

No P-waves or S-waves are detected in the shadow zone due to the refraction of P-waves and the absorption of S-waves by Earth's outer core.
Most characteristics of Earth's mantle and core are inferred from the behavior of seismic waves within Earth's interior.

Earth's Crust

Earth's oceanic crust is thinner and denser compared to the continental crust.
The basaltic bedrock of the oceanic crust is classified as mafic, exhibiting a density of 3.0 g/cm³.

Temperature and Pressure in Earth's Interior

The inferred temperature at the boundary between the stiffer mantle and the asthenosphere is approximately 2500°C.
Within Earth's stiffer mantle, the combination of temperature and pressure inferred is around 3500°C and 0.4 million atmospheres.

Geological Evidence and Processes

Evidence for crustal subsidence, or sinking, is indicated by the presence of shallow-water fossils located beneath the deep ocean.
The primary process responsible for forming hills is faulting.

Time Measurement

The time it takes for light to travel from the Sun to Earth is approximately 8 minutes and 20 seconds.

Description

Test your knowledge on the Earth's crust and seismic activity. This quiz covers important concepts about P-waves, S-waves, and the characteristics of continental and oceanic crusts. Understand the fundamental properties governing Earth's layers and their densities.