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

The Earth’s inner core is the 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.

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 wegner

Answer 10

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.

Question 13

Divergent Boundary

Answer 13

a divergent boundary or divergent plate boundary (also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other.

Question 14

Transform Boundary

Answer 14

A transform fault or transform boundary is a plate boundary where the motion is predominantly horizontal.

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

a hypothetical supercontinent that included all current land masses, believed to have been in existence before the continents broke apart during the Triassic and Jurassic Periods.

Question 17

Laurasia

Answer 17

The supercontinent of the Northern Hemisphere that, according to the theory of plate tectonics, broke up into North America, Greenland, Europe, and Asia except for the Indian subcontinent.

Question 18

Gondwana

Answer 18

an ancient supercontinent that broke up about 180 million years ago.

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

the largest and best-known genus of the extinct order of seed ferns known as Glossopteridales (also known as Arberiales or Ottokariales).