The dynamic earth

Question 1

Seismic waves

Answer 1

Waves of energy that travel through the Earth’s crust, caused by earthquakes

Question 2

Atmosphere

Answer 2

A blanket of gases that surrounds the Earth to a height of approximately 145 km. Mostly made up of nitrogen and oxygen, which supports life on Earth

Question 3

Crust

Answer 3

Includes landforms, rocks and soil. It is mostly solid rock, is rigid and has high strength. It varies in thickness from as little as 5 km under the ocean to about 70 km under mountain ranges

Question 4

Mantle

Answer 4

Partially molten rock. Temperatures mostly between 500C and 2000C. About 2900 km thick. The top part of the mantle is the source of magma that erupts onto the surface

Question 5

Hydrosphere

Answer 5

The water on or at the surface of the Earth, including oceans, lake, rivers, rain and mist

Question 6

Outer core

Answer 6

Molten iron and nickel. Temperatures mostly between 4000C and 6000C. About 2300 thick

Question 7

Inner core

Answer 7

Mostly iron. Solid owing to the extreme pressure. Temperatures up to 7000*C. About 1200 km thick

Question 8

Continental drift

Answer 8

Movement of the plates of the Earth’s crust in relation to each other

Question 9

Pangaea

Answer 9

A super-continent that existed about 225 million years ago. All of the landmasses that existed at this time were joined together to form this super-continent

Question 10

Panthalassa

Answer 10

The vast sea surrounding the supercontinent of Pangaea

Question 11

Plate tectonics

Answer 11

The theory concerning the movement of the continental plates

Question 12

Convection current

Answer 12

Circular movement that occurs when warmer, less dense fluid particles rise and cooler, denser fluid particles sink

Question 13

Continental crust

Answer 13

The plates of the Earth’s crust that make up the land

Question 14

Oceanic crust

Answer 14

One of the types of crust that makes up the Earth’s outer layer. Oceanic crust is thinner than continental crust and made up of dense, heavy rocks such as basalt

Question 15

Boundaries

Answer 15

The edges of tectonic plates

Question 16

Subduction

Answer 16

Process in which two tectonic plates push against each other, and oceanic crust sinks below the less dense continental crust

Question 17

Destructive plate boundaries

Answer 17

A convergent boundary where two plates collide

Question 18

Constructive plate boundaries

Answer 18

Plate that creates new land from cooling magma

Question 19

Ocean ridges

Answer 19

an area where the Tectonic plates move apart, allowing magma from the mantle to rise, forming underwater volcanoes and creating new oceanic crust as it is cooled and solidified by sea water

Question 20

Conservative plate boundaries

Answer 20

Boundaries between sliding plates, like the San Andreas Fault in the United States