Plate Tectonics

Question 1

Lithosphere

Answer 1

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

Question 2

Asthenosphere

Answer 2

the 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

the region of the earth’s atmosphere above the stratosphere and below the thermosphere, between about 30 and 50 miles (50 and 80 km) in altitude.

Question 4

Inner core

Answer 4

Earth’s innermost part.

Question 5

Outer Core

Answer 5

The 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. Its outer boundary lies 2,890 km beneath Earth’s surface

Question 6

Seismic Waves

Answer 6

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

Question 7

Oceanic Crust

Answer 7

the relatively thin part of the earth’s crust which underlies the ocean basins. It is geologically young compared with the continental crust and consists of basaltic rock overlain by sediments

Question 8

Continental Crust

Answer 8

the relatively thick part of the earth’s crust that forms the large landmasses. It is generally older and more complex than the oceanic crust.

Question 9

Density

Answer 9

the degree of compactness of a substance.

Question 10

Alfred Wegener

Answer 10

Alfred Lothar Wegener was a 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

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

Question 12

Convergent Boundary

Answer 12

Convergent boundaries are areas on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other causing a process known as subduction. The subduction zone can be defined by a plane where many earthquakes occur, called the Benioff Zone.

Question 13

Divergent Boundary

Answer 13

divergent boundary or divergent plate boundary is a linear feature that exists between two tectonic plates that are moving away from each other. Divergent boundaries within continents initially produce rifts which eventually become rift valleys.

Question 14

Transform Boundary

Answer 14

a plate boundary where the motion is predominantly horizontal. It ends abruptly and is connected to another transform, a spreading ridge, or a subduction zone

Question 15

Sea floor spreading

Answer 15

the 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

Pangaea

Answer 16

Super continent

Question 17

Laurasia

Answer 17

When Pangaea broke up, the northern continents of North America and Eurasia became separated from the southern continents of Antarctica, India, South America, Australia and Africa. The large northern continent is called Laurasia and the southern continent is called Gondwanaland.

Question 18

Gondwana

Answer 18

Gondwana was an ancient supercontinent that broke up about 180 million years ago. The continent eventually split into landmasses we recognize today: Africa, South America, Australia, Antarctica, the Indian subcontinent and the Arabian Peninsula.

Question 19

Mesosaurus

Answer 19

Mesosaurus (meaning “middle lizard”) is an extinct genus of reptile from the Early Permian of southern Africa and South America.

Question 20

Glossopteris

Answer 20

Glossopteris is the largest and best-known genus of the extinct order of seed ferns known as Glossopteridales. The genus Glossopteris refers only to leaves, within a framework of form genera used in paleobotany.