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 asthenosphere is the highly viscous, mechanically weak and ductilely deforming region of the upper mantle of the Earth. It lies below the lithosphere, at depths between approximately 80 and 200 km below the surfac

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

Question 4

Inner Core

Answer 4

Earths most inner part

Question 5

Outer Core

Answer 5

fluid layer about 2,300 km thick and composed iron and nickel

Question 6

Seismic Waves

Answer 6

a wave energy that travels through the Earth and away from an earthquake in all directions

Question 7

Oceanic Crust

Answer 7

the relatively thin part of the earth’s crust that 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 ratio of the mass of a substance to the volume of the substance

Question 10

Alfred Wegener

Answer 10

German geophysicist who proposed the theory of continental drift

Question 11

Continental Drift

Answer 11

the hypothesis that states that the continents once formed a single landmass, broke up and drifted to their present locations

Question 12

Convergent Boundary

Answer 12

the boundary formed by the collision of two lithospheric plates

Question 13

Divergent Boundary

Answer 13

the boundary between two tectonic plates that are moving away from each other

Question 14

Transform Boundary

Answer 14

the boundary between tectonic plates that are sliding past each other horizontally

Question 15

Sea-floor Spreading

Answer 15

the process by which new oceanic lithosphere forms as magma rises toward the surface and solidifies

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

A vast continental area believed to have existed in the southern hemisphere and to have resulted from the break-up of Pangaea in Mesozoic times. It comprised present-day Arabia, Africa, South America, Antarctica, Australia, and the peninsula of India.

Question 19

Mesosaurus

Answer 19

an extinct small aquatic reptile of the early Permian period, with an elongated body, flattened tail, and a long narrow snout with numerous needle-like teeth.

Question 20

Glossopteris

Answer 20

“tongue”, because the leaves were tongue-shaped, and pteris, Greek for fern or feathery) is the largest and best-known genus of the extinct order of seed ferns known as Glossopteridales