HMH Science Dimensions: Plate Tectonics Lesson 1 Quiz

What is the average thickness of Earth's continental crust?

35 km

Where is the crust of Earth's continents thickest?

Himalaya Mountains

Why haven't scientists collected samples from Earth’s core?

Extreme pressure and temperature make it impossible to reach the core.

What is the name of the deepest borehole on Earth located in northwestern Russia?

Kola Superdeep Borehole Signup and view all the answers

Which compositional layer of Earth is the outermost?

Crust Signup and view all the answers

What causes seismic waves?

Earthquakes Signup and view all the answers

What is the reason for the mantle being denser than the crust?

Compression by the weight of the rock above Signup and view all the answers

What evidence do scientists use to infer the properties of the asthenosphere?

Seismic waves refracting strongly Signup and view all the answers

What does the graph showing the velocity of P- and S-waves with depth in Earth’s mantle reveal?

Gradual changes show the flow of solid rock in the mantle Signup and view all the answers

What is the reason for the occurrence of the aurora borealis near the poles?

Magnetic alignment to Earth’s magnetic poles Signup and view all the answers

What drives the flow of the solid rock of the mantle according to the text?

Differences in density caused by differences in temperature Signup and view all the answers

What are scientists able to infer about the asthenosphere based on seismic data?

It is very bendable like putty or clay Signup and view all the answers

Why do many stony meteorites appear to be similar to rock on Earth’s crust?

They are unchanged since they formed 4.56 billion years ago Signup and view all the answers

What do seismic waves reveal about the internal layers of Earth?

Two internal layers: an outer core that is liquid and an inner core that is solid Signup and view all the answers

What drives convection in the mantle according to the text?