Unit 7 Vocabulary

Question 1

Tectonic plates

Answer 1

Huge pieces of lithosphere that move around on top of the asthenosphere

Question 2

Asthenosphere

Answer 2

The solid, soft layer of the mantle, between the mesosphere and lithosphere. Differences in temperature and pressure cause convection currents which provide the layer on which tectonic plates move

Question 3

Convection currents

Answer 3

The circular motion of liquid or gas is caused by density differences that result from temperature differences such as convection of magma in earths mantle

Question 4

Plate tectonics

Answer 4

The theory that the lithosphere is divided into tectonic plates that move around on top of the asthenosphere. This theory explains how moving plate shape
land features and how plate mention relates to earth processes such as volcanic eruptions

Question 5

Pangaea

Answer 5

Wenger’s name for a supercontinent that existed about 245 million years ago, and from which all present-day continents are formed

Question 6

Continental drift

Answer 6

The theory that today’s continents were once part of a single land mass that broke into pieces that drifted apart from one another into the present day locations. It also suggest they are still drifting

Question 7

Seafloor spreading

Answer 7

The process by which a new organic lithosphere(sea floor crust)forms at mid ocean ridges. As the new crust forms, it pushes existing crust in the opposite direction away from the ridge

Question 8

Rifting

Answer 8

The process by which earth’s lithosphere pulls apart to form long, narrow, faulted a rift valleys and rift zones

Question 9

Mid Ocean Ridge/raft zone

Answer 9

The most common type of divergent boundary. If located on the ocean floor it is called ridge, if located on land it is called a rift. Both types contain fault block mountains and volcanic mountains

Question 10

Folding

Answer 10

The type of deformation that occurs when rock bend because of compression stress

Question 11

Faulting

Answer 11

The type of deformation that occurs when rocks break because of compression stress of tension stress

Question 12

Subduction

Answer 12

The process by which oceanic lithosphere sinks down into the asthenosphere at a convergent boundary

Question 13

Divergent boundary

Answer 13

The boundary between two tectonic plates that are moving away from each other. Aka rift zone

Question 14

Convergent boundary

Answer 14

The boundary between two colliding tectonic plates

Question 15

Transform boundary

Answer 15

The boundary between two tectonic plates that are sliding past each other

Question 16

Deformation

Answer 16

Any change in a rocks shape or volume caused by compression, tension, or sheer stress

Question 17

Volcanic mountains

Answer 17

Type of mountain that forms when magma ethos onto earths surface

Question 18

Fault block mountains

Answer 18

Occur along divergent boundaries where faulting causes large blocks of earths crust to drop down relative to other blocks. They can sometimes occur along convergent boundaries where one block of rock is thrust over another block of rock

Question 19

Folded mountains

Answer 19

Occur along convergent boundaries and where the bending of rock is due to compression stress of earths crust. The compression results in folding and faulting of rock that creates folded mountain belts

Question 20

Compression

Answer 20

Stress that squeezes or shortens material such as rock. In places where rock is less rigid, compression creates folds. In places where the rock is more rigid, compression can create faults

Question 21

Stress

Answer 21

Amount of force per unit area that is put on a rock

Question 22

Sheer stress

Answer 22

A stress that occurs when two tectonic plates move side by side past one another, causing material to twist and become distorted

Question 23

Tension

Answer 23

Stress that lengthens and pulls material such as rock apart. In places where tension is greater then the strength of the rock, the rock faults or breaks

Question 24

Ocean trenches

Answer 24

Deepest landform found on the ocean floor. They are created along convergent boundaries where one plate is us ducted under another tectonic plate

Question 25

Volcanic island arcs

Answer 25

These island chains are formed parallel to ocean trenches as the magma produced by subduction erupts as lava

Question 26

Hot spots

Answer 26

Places where volcanic island chains form far from tectonic plate boundaries. At a hot spot, magma rises from deep within the earth and eventually builds an island. As the oceanic plates move, a new part of the crust is positioned over the hot spot and the process of island building begins. Older islands in the chain are located further away from the hot spot and the newer islands are closer

Question 27

Tectonic setting

Answer 27

The position of a particular landform within a tectonic plate. The setting information should include the type of plates and tectonic boundary

Question 28

Lithosphere

Answer 28

The cool, rigid outermost layer of the earth that is divided into enormous pieces called tectonic plates