Science Chapter 17: Plate Tectonics; Grade 8

Magnetic reversal

A change in Earth's magnetic field is called a(n) ______.

Rift valley

A long, narrow, fault-bounded, continental depression is a(n) _______.

Isochron

A map line connecting points that have the same age is a(n) _______.

Magnometer

A(n) _______ detects small changes in Earth's magnetic field.

Younger

Compared to ocean crust near deep-sea trenches, crust near ocean ridges is

Wegener couldn't explain how or why the continents moved.

Continental drift wasn't widely accepted when it was first proposed because

Pangaea

Earth's continents were once joined as a single landmass called ______.

Matching coastlines

Many early mapmakers thought Earth's continents had moved based on

Paleomagnetism

The study of Earth's magnetic record is known as ________.

Divergent boundaries

Places where plates move apart are ______.

Convergent boundaries

Plates come together at ______.

Theory of plate tectonics

The ________ states that Earth's crust and rigid upper mantle are broken into enormous slabs called plates that move slowly over Earth's surface.

A mirror image of that of the other side

The magnetic pattern of ocean-floor rocks on ome side of an ocean ridge is

Seafloor spreading

The theory of ______ explains how new ocean crust is created at ocean ridges and destroyed in deep-sea trenches.

Convection

The transfer of thermal energy by the movement of heated matter is ______.

Continental drift

Wegener's hypothesis of ________ stated that Earth's continents had once been joined as a single landmass.

Subduction

______ occurs when one tectonic plate descends beneath another.

Ridge push

_______ is a process whereby the weight of an uplifted ocean ridge pushes an oceanic plate toward a subduction zone.

Transform boundaries

________ are places where plates slide horizontally past each other.