Chapter 1: The Earth System

Question 1

asthenosphere

Answer 1

The weak layer of soft but solid rock comprising the lower part of the upper mantle (below the lithosphere) and over which the plates slide. Movement in the asthenosphere occurs by plastic deformation.

Question 2

climate system

Answer 2

A geosystem that includes all parts of the Earth system and all the interactions among these components needed to describe how climate behaves in space and time.

Question 3

core

Answer 3

The central part of the Earth below a depth of 2900 km, comprising a liquid outer core and a solid inner core.

Question 4

crust

Answer 4

The thin outer layer of the Earth, averaging about 8 km thick under the oceans to about 40 km thick under the continents, consisting of relatively light materials that melt at low temperatures.

Question 5

Earth system

Answer 5

All the parts of our planet and all their interactions, taken together. The collection of Earth’s open, interacting, and often overlapping geosystems.

Question 6

fossil

Answer 6

Trace of an organism of past geologic ages that has been preserved in the crust.

Question 7

geodynamo

Answer 7

The global geosystem that sustains Earth’s magnetic field, driven by convection in the outer core.

Question 8

geosystem

Answer 8

A specialized subsystem of the Earth system that encompasses specific types of terrestrial behavior/geologic activity.

Question 9

inner core

Answer 9

The central part of the Earth from a depth of 5150 to 6370 km, composed of iron and nickel. A solid metallic sphere with a radius of 1220 km suspended within the liquid outer core.

Question 10

lithosphere

Answer 10

The strong, rigid outer shell of the Earth that encases the asthenosphere and contains the crust and the uppermost part of the mantle down to an average depth of about 100 km and forms the rigid plates.

Question 11

magnetic field

Answer 11

The region of influence of a magnetized body or an electric current.

Question 12

mantle

Answer 12

The region that forms the main bulk of the solid Earth, between the crust and the core, ranging from depths of about 40 km to 2900 km.

Question 13

outer core

Answer 13

A liquid zone composed of iron, nickel, and minor amounts of some lighter element, such as oxygen or sulfur below the mantle, from a depth of 2890 to 5190 km, that surrounds a solid iron-nickel inner core.

Question 14

plate tectonic system

Answer 14

A geosystem that includes all parts of the Earth system and all the interactions among these components needed to describe how plate tectonics works in space and time. Includes the convecting mantle and its overlying mosaic of lithospheric plates.

Question 15

principle of uniformitarianism

Answer 15

The principle that the geologic processes we see in action today have worked in much the same way throughout geologic time; that is, the present is the key to the past.

Question 16

scientific method

Answer 16

A general research plan, based on methodical observations and experiments, by which scientists propose and test hypotheses that explain some aspect of how the universe works.

Question 17

seismic wave

Answer 17

A ground vibration produced by earthquakes or explosions.

Question 18

topography

Answer 18

The general configuration of varying heights that gives shape to Earth’s surface.

Question 19

climate

Answer 19

The average conditions of Earth’s surface environment and their variation

Question 20

convection

Answer 20

The mechanical transfer of heat energy that occurs as a heated material expands, rises, and displaces cooler material, which is itself heated and rises to continue the cycle.

Question 21

geodesy

Answer 21

The science of measuring the shape of Earth and locating points on its surface.

Question 22

geologic record

Answer 22

Information about geologic events and processes that has been preserved in rocks as they have formed at various times throughout Earth’s history.

Question 23

geology

Answer 23

The branch of Earth science that studies all aspects of the planet: its history, its composition and internal structure, and its surface features.

Question 24

nebular hypothesis

Answer 24

Explains the formation of the solar system

Question 25

differentiation

Answer 25

The process by which an originally homogeneous Earth developed a dense core and a light crust

Question 26

Vallis Marineris

Answer 26

The longest and deepest canyon in the solar system

Question 27

Mohs Hardness Scale

Answer 27

1 Talc
2 Gypsum/Selenite
3 Calcite
4 Fluorite
5 Apatite
6 Orthoclase Feldspar/Microcline
7 Quartz
8 Topaz
9 Corundum
10 Diamond

Question 28

geophysics

Answer 28

A branch of science that deals with the physical movements and forces of the Earth (such as its climate and oceans)

Question 29

Emil Wiechert

Answer 29

Looked to meteorites for why the earth was so dense

Question 30

Robert Oldham

Answer 30

Sorted out the paths of the two types of waves (P&S)

Question 31

Beno Gutenberg

Answer 31

Confirmed the core-mantle boundary

Question 32

Mohorovicic

Answer 32

Found the boundary between the crust and mantle

Question 33

Inge Lehmann

Answer 33

Confirmed the existence of the inner and outer cores

Question 34

isostasy

Answer 34

A principle stating that the buoyancy force that pushes upward a lower-density body (continent) floating in a higher-density medium (asthenosphere) must be balanced by the gravitational force that pulls it downward.