Unit 12

Question 1

Inner core

Answer 1

a) solid and dense
b) iron and Nickle exist here in a solid state due to high pressure
c) radius is only 1,220km (760 miles) & surface is 5,150km below sea level
d) incredibly hot at the center; 6000 Celsius/10832 F

Question 2

outer core

Answer 2

a) Liquid
b) Consist of same materials as inner core
c) Pressure is less, so the molten state prevails
d) 2,250km (1400 miles) & surface lies 2900 km below sea level
e) Temperature ranges 8100-9900 F

Question 3

Lower mantle

Answer 3

A) Sometimes referred to as Mesosphere
B) 22,230 km thick
C) More solid than upper mantle
D) Composed of iron, magnesium, and silicon compounds

Question 4

Upper Mantle

Answer 4

A) Extends from the base of the crust to a depth of just 670 KM
B) Less dense and not a solid
C) Interacts with crust

Question 5

Lower Part of upper mantle

Answer 5

consists of molten rock & called asthenosphere

Question 6

Upper part of upper mantle

Answer 6

less molten and transitioning into a solid; becomes more rigid and rock like as you approach the surface & called Lithosphere

Question 7

crust

Answer 7

 Mohorovicic “moho” Discontinuity; 1909; Andrija Mohorovicic (Croatian scientist)
 Dividing line between the crust and mantle
A) Lies directly above mantle
B) Thickness varies (5km-40km)
C) Elements, minerals, and rocks found here

Question 8

Continental Crust

Answer 8

portion of earth that forms continent; landmass; thicker; low density; called a root; felsic rocks

Question 9

Oceanic Crust

Answer 9

thin; more dense; made up of mafic rocks

Question 10

Underwater Lithosphere: The ocean Basins

Answer 10

Secrets of submerged 71 percent of lithosphere are finally being revealed

Question 11

Technological advances

Answer 11

• sounding devices have allowed for ocean floor topography mapping
• deep sea submersibles

Question 12

The Ocean Basins

Answer 12

• Ocean floors have varied topography (not extension of land)
• Divided into three categories: margins of continents, the abyssal zone, systems of ridge surrounded by fractures and reliefs

Question 13

Continental Shelf

Answer 13

outlines the continents that is shallow (Ocean depths are less than 600ft) Gently sloping, submerged plane at edge of continent. (width 50-700 miles)

Question 14

Continental slope

Answer 14

begins where the continental shelf ends and plunges steeply downward

Question 15

Continental rise

Answer 15

transition zone of gently sloping seafloor; pile of debris; leads to abyssal zone

Question 16

Abyssal Plains

Answer 16

large expansions of low relief ocean floor; forms floors of deepest areas of ocean; contains hills, mountains, seamounts

Question 17

Midocean ridge

Answer 17

active submarine volcanism and major movement of earth’s crust; associated with a divergent plate boundary; contains volcanic activity and mountain ridges; EX: mid-Atlantic ridge

Question 18

Elements

Answer 18

A) Building blocks (base substances) of minerals

B) Most of the earth’s crust is made up of 8 elements: oxygen, silicon, others

Question 19

Minerals

Answer 19

A) Building blocks of rocks which are made of elements
B) Characteristics: solid, inorganic substances (not living) specific chemical formula and ordered atomic structure
C) Example: fool gold; pyrite

Question 20

Mineral Identification Methods

Answer 20

A) Streak: the color of a mineral when made into a fine powder
B) Fracture: the way a mineral breaks
C) Cleavage: the tendency of a mineral to break along a flat, planar surface based on its structure; a type of fracture

Question 21

Rocks

Answer 21

A) Made up of minerals

B) 3 types: igneous, sedimentary, and metamorphic

Question 22

Igneous

Answer 22

A) Form when magma or lava cools and solidifies: magma vs. lava?
B) Lava is molten material on the surface & magma is molten material that is inside the earth

Question 23

Intrusive

Answer 23

forms inside Earth
A) Forms when magma cools slowly below the earth’s surface
B) Large, well-formed crystals
C) Ex: granite

Question 24

Extrusive

Answer 24

forms on earth’s surface
A) Form when Lava cools rapidly above the Earth’s surface (smooth)
B) Small crystals
C) Ex: obsidian& pummis exception because of trapped air bubbles

Question 25

Sedimentary Rocks

Answer 25

A) Form from pre-existing rocks or pieces of once-living organisms
B) Broken into fragments through weathering: wind, water, ice
C) These deposits become buried underneath until they are compacted and cemented together – responsible for creating fossils

Question 26

Fossils

Answer 26

A) “sue” -largest and most complete tyrannosaurus rex skeleton ever found

Question 27

Metamorphic Rock

Answer 27

A) Form when other rock types are subject to heat and pressure
B) Foliation occurs when pressure is unequal, causing the minerals within the rock to orient themselves along the direction of pressure
C) Not as many test to determine metamorphic rocks

Question 28

Foliated-striped

Answer 28

crystals are lined up

Question 29

Non-foliated-non-striped

Answer 29

crystals have no shape