Chapter 9 Plate Tectonics

What happens at a transform plate boundary?

This plate motion is caused by currents in the asthenosphere that circulate & drag the lithosphere.

_________ is a state in which magnetized objects would orient themselves to point south.

Wegener found that mountain ranges on what 2 continents lined up to form a long, continuous mountain belt?

What did Wegener's hypothesis of continental drift suggest?

________ is a force that drags a plate into a subduction zone.

Tectonic plates move over the plastic-like _______.

Scientists now understand that continents move because the ______ moves beneath the _______.

Plate tectonic activity is related to ________ in the mantle.

The Theory of Plate Tectonics states that Earth's surface is made of _____, that moves with respect to each other.

________ is a force that occurs at a convergent plate boundary.

Which of these situations does NOT occur along a convergent plate boundary?

A subduction zone is located at a(n) ________ plate boundary.

Crust is not created or destroyed along a(n) _____ plate boundary.

Mountain ranges in the middle of the oceans are called _______.

What is the lowest natural point on Earth's land surface?

Magnetic stripes in the ocean crust support seafloor spreading because the stripes _______.

A(n) ________ occurs when the magnetic field reverses direction.

Basalt on the seafloor contains _________ which are magnetic.

Many of California's earthquakes are caused by __________.

Where & when was the world's strongest recorded earthquake?

Wegener's proposal of a supercontinent was supported by _________.

New crust forms at _____ plate boundaries.

What is the largest, currently active volcano on Earth today?

How does seafloor spreading support continental drift?

Why was Wegener's continental drift hypothesis rejected when it was proposed?

Sediment closest to the mid-ocean ridge is ______ than sediment farther away from the ridge.

The _______ amount of thermal energy leaves the Earth far from mid-ocean ridges.

A(n) _________ occurs when stress builds at a plate boundary & then releases rapidly.

_______ provides evidence that a giant landmass existed near the equator about 250 million years ago.

What is the area of the ocean floor called where thick layers of sediment can be found?

What mechanism to support Wegener's continental drift hypothesis was found in the 1960s?

What is the biggest body of freshwater on Earth's surface?

________ in South America, Africa, & Australia suggest that these continenets were once located in a much colder place.

________ found in Antarctica suggest that this continent once had a warm climate.