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Flashcards in Chapter 12 Deck (19):
1

The transfer of heat through matter by molecular activity

Conduction

2

The transfer of heat by the mass movement or circulation of a substance

Convection

3

The innermost layer of Earth based on composition. It is thought to be largely an iron-nickel alloy with minor amounts of oxygen, silicon, and sulfur

Core

4

The gradual increase in temperature with depth in the crust. The average is 30 degrees C per kilometer in the upper crust

Geothermal Gradient

5

The solid innermost layer of earth, about 1216 kilometers in radius

Inner core

6

The rigid outer layer of Earth, including the crust and upper mantle

Lithosphere

7

Lies between the transition zone and the liquid core, contains the mineral perovskite, is the earths largest layer occupying 56% of the volume of the planet

Lower mantle

8

The solid rocky shell that extends from the base of the crust to a depth of 2900 kilometers

Mantle

9

A field that surrounds the Earth because of Earths convection currents in earths liquid iron core

Magnetic field

10

A subdivision of the mantle situated below the lithosphere. This zone of weak material exists below a depth of about 100 kilometers and in some regions extends as deep as 700 kilometers. The rock within this zone is easily deformed.

Asthenosphere

11

The part of the mantle that extends from the core-mantle boundary to a depth of 660 kilometers. Also known as lower mantle

Mesosphere

12

The boundary separating the crust and the mantle, discernible by an increase in seismic velocity

Moho

13

A layer beneath the mantle about 2270 kilometers thick, which has the properties of a liquid

Outer core

14

The zones between 105 and 140 degrees distance from an earthquake epicenter, which direct waves do not penetrate because of refraction by Earth's core

Shadow zones

15

When seismic wave hits a boundary between different Earth materials and waves are reflected back toward surface

Seismic reflection

16

The bending of seismic waves while passing through the Earth

Seismic refraction

17

The actual shape of the earth, which is rough and oblate, or slightly squashed; the earths circumference is longer around the equator than it is along the meridians

Geoid

18

The paths of the seismic waves

Seismic Rays

19

Boundary layer between the rocky mantle and the liquid iron outer core; large variations in composition and temperature

D" layer