plate tectonics

Question 1

lithosphere

Answer 1

rigid outer part of the earth, consisting of the crust and upper mantle

Question 2

asthenosphere

Answer 2

upper layer of the earth’s mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur

Question 3

mesosphere

Answer 3

region of the earth’s atmosphere above the stratosphere and below the thermosphere, between about 30 and 50 miles

Question 4

inner core

Answer 4

It is primarily a solid ball with a radius of about 1,220 kilometres

Question 5

outer core

Answer 5

outer core of the Earth is a fluid layer about 2,400 km thick and composed of mostly iron and nickel that lies above Earth’s solid inner core and below its mantle

Question 6

seismic waves

Answer 6

elastic wave in the earth produced by an earthquake or other means

Question 7

oceanic crust

Answer 7

thin part of the earth’s crust which underlies the ocean basins

Question 8

continental crust

Answer 8

thick part of the earth’s crust that forms the large landmasses

Question 9

density

Answer 9

degree of compactness of a substance

Question 10

alfred wegener

Answer 10

German polar researcher, geophysicist and meteorologist. During his lifetime he was primarily known for his achievements in meteorology and as a pioneer of polar research

Question 11

continental drift

Answer 11

gradual movement of the continents across the earth’s surface through geological time

Question 12

convergent boundary

Answer 12

areas on Earth where two or more lithospheric plates collide

Question 13

divergent boundary

Answer 13

a linear feature that exists between two tectonic plates that are moving away from each other

Question 14

transform boundary

Answer 14

a plate boundary where the motion is predominantly horizontal

Question 15

sea floor spreading

Answer 15

formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges and its subsequent outward movement on either side

Question 16

pangea

Answer 16

was a supercontinent that existed during the late Paleozoic and early Mesozoic eras

Question 17

laurasia

Answer 17

part of Pangaea that lies in the Southern Hemisphere. It includes most of the present-day South America, Africa, India, Australia, and Antarctica

Question 18

gondwana

Answer 18

ancient supercontinent that incorporated present-day South America, Africa, Arabia, Madagascar, India, Australia, and Antarctica

Question 19

mesosaurus

Answer 19

an extinct genus of reptile from the Early Permian of southern Africa and South America

Question 20

glossopteris

Answer 20

genus of the extinct order of seed ferns known as Glossopteridales