Chapter 9 Plate Tectonics

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

_______ 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?

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

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

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

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

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

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

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

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

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

Many of California's earthquakes are caused by __________.

How does seafloor spreading support continental drift?

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

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

Tectonic plates move over the plastic-like _______.

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

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

What happens at a transform plate boundary?

What did Wegener's hypothesis of continental drift suggest?

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

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

Plate tectonic activity is related to ________ in the mantle.

New crust forms at _____ plate boundaries.

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

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

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

Basalt on the seafloor contains _________ which are magnetic.

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

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

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

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

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

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