test 2

Question 1

What are the three major components of the Earth and their features?

Answer 1

Surface/Crust – is made of thinner oceanic plates and thicker continental plates
Mantle – makes most of the earths diameter and is under high pressure
Core – near center and under high pressure composed of metallic iron and nickel, outer core is molten, and the inner core is solid

Question 2

What are the three possible movements of plates, relative to each other?

Answer 2

Divergent – push away from each other
Convergent – push towards each other, when oceanic and continental plates come together oceanic plate falls under because it is thinner
Transform – plates slide against each other in opposite directions

Question 3

Where are divergent plates commonly found?

Answer 3

Along plate boundaries

Question 4

What are the three types of convergent plates?

Answer 4

Oceanic – Oceanic
Continental – Continental
Continental – Oceanic

Question 5

What happens at a transform plate boundary?

Answer 5

The friction from the sliding produces faults and causes earthquakes

Question 6

Name and describe types of forces that can cause the Earth material to move?

Answer 6

Compression – material is forced together
Tension – material pulled apart
Shear – creates horizontal movement

Question 7

What is a fault? What are the four types?

Answer 7

A fault is movement of two beds, either vertical or horizontal
Normal fault – hanging wall moves down
Reverse fault – hanging wall moves up
Thrust fault – reverse fault with folding (bending) of hanging wall
Strike-slip fault – lateral movement

Question 8

Describe the five types of folds.

Answer 8

Anticlines – A shape
Syncline – U or V shape
Dome – uplift in a circular area
Basin – Opposite of dome, center is downward
Monocline – mostly flat areas with only one-fold downward

Question 9

What are the four basic causes of an earthquake?

Answer 9

Movement along faults
Activity around volcanoes
Gravitational movement of material can result in Landslides
Variety of explosions (human caused or natural)

Question 10

Describe the terms hypocenter and epicenter relative to an earthquake.

Answer 10

The point of the earthquake is the hypocenter (including depth below surface), the earth surface above is the epicenter

Question 11

How can a seismometer be used to measure an earthquake?

Answer 11

It records earth vibrations by showing the amount of movement as squiggles

Question 12

Relative to an earthquake, what are P-waves and S-waves?

Answer 12

Primary waves are the result of compression moving the fasted
Secondary waves are movements perpendicular and move slower

Question 13

How can we determine the location of an earthquake?

Answer 13

By using three stations to record the waves and triangulate them

Question 14

What is the magnitude of an earthquake?

Answer 14

The strength of the earthquake – how much the earth shakes

Question 15

Describe how the Richter scale is used to measure the magnitude of an earthquake.

Answer 15

A scale from 1-10 but each level is 10 times greater than the last, 3 is 10 times greater than 2
Lowest is 1 and most powerful is 10

Question 16

Where are earthquakes most common?

Answer 16

Oceanic continental plate boundaries
The rift valley of Africa
Along mid oceanic ridges

Question 17

What are the outcomes of earthquakes?

Answer 17

Human structures can collapse, rockslides, material can lift, settle, or slide, and under water earthquakes can cause tsunamis

Question 18

What is magma?

Answer 18

Molten material that has come outside to earth’s surface

Question 19

How and why does magma vary between solid and liquid within the Earth?

Answer 19

Changes in temperature and pressure
With very high pressure material stays solid, but loss of pressure may result in turning liquid

Question 20

In what ways does magma change as it moves closer to the Earth’s surface?

Answer 20

The reduced pressure can cause partial or complete melting as it moves toward the surface

Question 21

How do temperature, composition, and crystals influence the movement of magma?

Answer 21

Temperature
High – very liquid, below the surface
Low – thick, closer to surface
Composition
Few silicates can move easier
Water dissolved in magma can even vaporize
Presence of crystals
More crystals – slower movement
Fewer crystals – faster movement

Question 22

Name and contrast the four types of volcanoes.

Answer 22

Shield volcanoes – have gently curved slopes with one or more crater
Composite volcanoes – symmetrical tall mountains with a crater top
Scoria cones – cone shape with small crater at top, much rock and debris
Volcanic domes – dome-shape mostly of magma, little ash

Question 23

Describe a flava flow and a pyroclastic eruption.

Answer 23

Lava flows produce flows of lava and are not very viscus,
pyroclastic eruptions are explosive and throw out much debris including rocks and ash

Question 24

In what ways should we worry about volcanic eruptions?

Answer 24

Falling objects
Ash in the air
Other gases in the air
Blocked sunlight

Question 25

Describe the features of a basaltic volcano.

Answer 25

Can produce a jumble of angular blocks, or ropy material
As it moves into water can produce pillows

Question 26

Describe the features of a composite volcano.

Answer 26

Produce eruption columns
Has viscus lava, but doesn’t move far
Has layers of lava, debris, ash

Question 27

What is a Caldera?

Answer 27

Large basin shaped volcanic depression

Question 28

How are mid oceanic ridges associated with volcanoes?

Answer 28

Because they create cracks in the earth’s surface, magma moves into the cracks and the volcanoes process starts very small amounts produced at any one time