Dynamic Earth vocablulary words

Question 1

Asthenosphere

Answer 1

A hot, malleable semiliquid zone in the upper mantle, directly underneath the lithosphere, on which the plates of the lithosphere move (or float).

Question 2

Boundary

Answer 2

The border between two tectonic plates

Question 3

Collision zone

Answer 3

The place where a collision between two continental plates crunches and folds the rocks at the boundary, lifting them up and leading to mountain formation.

Question 4

Continental crust

Answer 4

A layer of the earth’s crust that lies under the seven continents. It is about 20 to 40 miles (35 to 70 km) thick and very old.

Question 5

Convergent boundary

Answer 5

The boundary that occurs where two plates are pushing toward each other.
The boundary that occurs where two plates are pushing toward each other.
The boundary that occurs where two plates are pushing toward each other.
The boundary that occurs where two plates are pushing toward each other.

Question 6

Crust

Answer 6

Hard and rigid, the earth’s outermost and thinnest layer. It is only a few miles (5 km) thick under the oceans and averages 20 miles (30 km) thick under the continents.

Question 7

Divergent boundary

Answer 7

The boundary that occurs where two plates are moving apart from each other

Question 8

Earthquake

Answer 8

A trembling and shaking of the earth’s surface resulting from the sudden release of energy in the crust, either along fault lines or from volcanic activity

Question 9

Fault

Answer 9

A crack or fracture in earth’s crust where two tectonic plates grind past each other in a horizontal direction

Question 10

Inner core

Answer 10

The innermost layer of the earth, an extremely hot, solid sphere of mostly iron and nickel. The inner core is 3,200 to 3,960 miles (5,150 to 6,378 km) below the surface and about 750 miles (1,200 km) thick.

Question 11

Lithosphere

Answer 11

Make up of the crust and a tiny bit of the upper mantle, this zone is divided into several constantly (very slowly) moving plates of solid rock that hold the continents and oceans

Question 12

Magma

Answer 12

Molten rock that flows beneath the earth’s surface and is made up of gases, liquids, and crystals. When magma reaches the surface, it is called lava.

Question 13

Mantle

Answer 13

This dense layer of the earth is made of hot, semisolid rock and is located directly below the crust. It is about 1,800 miles (2,900 km) thick.

Question 14

Mid-ocean ridge

Answer 14

A raised area or mountain range under the oceans formed when magma fills the space between two tectonic plates that are spreading apart

Question 15

Oceanic crust

Answer 15

The type of crust lying under the oceans of the world. It is only 4 to 6 miles (7 to 10 km) thick and usually younger than continental crust.

Question 16

Outer core

Answer 16

This layer of the earth lies between the mantle and the solid inner core. It is the only liquid layer, a sea of mostly iron and nickel about 1,400 miles (2,300 km) thick.

Question 17

Pangaea

Answer 17

The name given to the supercontinent that existed more than 225 million years ago, in which the present-day continents were joined together in one large landmass.
The name given to the supercontinent that existed more than 225 million years ago, in which the present-day continents were joined together in one large landmass.
The name given to the supercontinent that existed more than 225 million years ago, in which the present-day continents were joined together in one large landmass.
The name given to the supercontinent that existed more than 225 million years ago, in which the present-day continents were joined together in one large landmass.
The name given to the supercontinent that existed more than 225 million years ago, in which the present-day continents were joined together in one large landmass.

Question 18

Rift

Answer 18

A dropped zone where two tectonic plates are pulling apart.

Question 19

Seafloor Spreading

Answer 19

The process that forms new ocean floor and oceanic crust. Magma oozes up from the mantle through a crack in the ocean floor, filling in the space between the plates and spreading out from the plate boundary.

Question 20

Subduction zone

Answer 20

The place where one plate is getting bent and pulled under the edge of another plate.

Question 21

Tectonic Plates

Answer 21

Several large slabs of the lithosphere that hold the continents and oceans and are slowly but constantly moving around the earth.

Question 22

Transform Boundary

Answer 22

The boundary that occurs where two plates slide past each other.
The boundary that occurs where two plates slide past each other.
The boundary that occurs where two plates slide past each other.

Question 23

Trench

Answer 23

A deep valley that forms at the edge of a continent when an oceanic plate sinks underneath a continental plate.

Question 24

Tsunami

Answer 24

A huge ocean wave caused by a sudden, powerful shift on the ocean floor, like an undersea earthquake, landslide, or volcanic eruption.