Chapter 13

Question 1

MINERAL

Answer 1

Inorganic natural solid compound having a specific chemical formula and usually possessing a crystalline structure

Question 2

CRATON

Answer 2

All continents have a nucleus of ancient crystalline rock on which it grows through the addition crustal fragments and sediments

Question 3

CONTINENTAL SHIELD

Answer 3

A large region where a craton is exposed at the surface

Question 4

PASSIVE MARGIN

Answer 4

Where two plates are joined together, where they move as a single mass.

Question 5

What is the driving force behind plate motion?

Answer 5

• convection currents in the mantle

- grab hold of the underside of the crust (plates) and drags it along

Question 6

Plate Margins

Answer 6

Where plates meet

3 TYPES:

1. Convergent
2. Divergent
3. Transform

Question 7

Convergent Plate Margin

Answer 7

Where plates collide head on

Question 8

Faulting

Answer 8

When a rock breaks

Question 9

Folding

Answer 9

When a rock bends

Question 10

Earthquake

Answer 10

An earthquake is a sudden shaking of the ground due to a release of energy deep inside the Earth

Question 11

Focus

Answer 11

The place in the ground where energy is released and where the earthquakes originate

Question 12

Epicenter

Answer 12

The place on the surface directly above the focus

Question 13

Divergent Plate margin

Answer 13

Where plates are moved apart

Question 14

Transform margin

Answer 14

Where plates are moving past each other in a side to side motion

Question 15

“P” or Primary Waves

Answer 15

Causes objects at the surface to move side to side
aprox. 8km/s

• faster
• cause things to go back and forth sideways

Question 16

“S” or Secondary Waves

Answer 16

Causes objects at the surface to move up and down
aprox. 5km/s

• slower
• these cause things to sway

Question 17

Liquefaction

Answer 17

The fluidization of water-saturated sediment when it is shaken.

• loss of strength and stiffness in response to stress, in this context, an Earthquake

Question 18

RELIEF

Answer 18

difference between high and low.

Elevation differences in a local landscape; an expression of local height differences of landforms

Question 19

TERRANE

Answer 19

A rock body formed at one location and moved to another by plate motion.

(example: insular belt in BC, including Vancouver island)

Question 20

TYPES OF STRESS

Answer 20

(THREE TYPES)

1. Compressive Stress
2. Tensional Stress
3. Shear Stress

Question 21

COMPRESSIVE STRESS

Answer 21

• forces are directed inward.
• causes shortening
• creates symmetrical folds
• folding caused: anti cline (hump is on top) r syncline fold (hump on bottom)
• faulting caused: reverse fault (one rock body has moved up and over the other rock body which has moved down and under.

Question 22

TENSIONAL STRESS

Answer 22

• forces are directed outward
• causes stretching, maybe thinning
• folding caused: no folding
• faulting caused: normal fault
• because of tensional stress one rock body has moved down and away from the other which has moved up and away

Question 23

SHEAR STRESS

Answer 23

• forces are opposite to one another in a side-by-side motion
• causes twisting or tearing
• folding caused: asymmetrical anticline, asymmetrical syncline
• faulting caused: Right lateral/left lateral strike-slip fault

Question 24

List Historical Eruptions

Answer 24

• Mt. Mazama (Crater Lake, Oregon.) (6,600 years ago)
• Mt. Vesuvius, Italy (Burial of Pompeii) (2,000 years ago)
• Mt. St. Helen (Washington State (May 18, 1980)
• Mt. Dinatubo Philippines, (1991)

Question 25

Volcano

Answer 25

a volcano is a hill or mountain that forms on the Earth’s surface over a hole in the crust; out of which comes lava (liquid rock), gas (water) and pyroclastic debris (rock fragments such as ash)

Question 26

Pyroclastic Flows

Answer 26

a fast moving avalanche of hot rock and gas that is very destructive.

Question 27

Harmonic Tremors

Answer 27

Seismic energy releases associated with volcanos. - many small earthquakes around the magma chamber that suggest a change in the behaviour of the volcano and the possibility of an eruption.

Question 28

Lahar

Answer 28

Debris flow caused by a volcanic eruption. - moderately fast flow of wet sediment that follows the pre-existing drainage of the land.

Question 29

TYPES OF VOLCANIC ERUPTIONS

Answer 29

1. Explosive | 2. Non Explosive (Effusive)

Question 30

EXPLOSIVE ERUPTION (6 characteristics)

Answer 30

- Located on a continental plate - Rock type is felsic - Lava viscosity is high (flows slower) - Rate of gas escape is low, until it erupts suddenly - Duration of eruption is faster - Frequency of eruption is rare

Question 31

EFFUSIVE (NON-EXPLOSIVE) ERUPTION (6 characteristics)

Answer 31

- Located on an oceanic plate - Rock type is mafic - Lava viscosity is low, (flows easily) - Rate of gas escape is faster (gas escaping constantly) - Duration of eruption is longer - Frequency of eruption is common

Question 32

TYPES OF VOLCANOS BASED ON APPEARANCE

Answer 32

- Strato | - Shield

Question 33

Strato Volcano (composite volcano)

Answer 33

Tall, steep-sided, prominent structure like Mt. Baker. - composed of layers of lava and pyroclastic debris - weak internal structure that makes the volcano prone to failure

Question 34

Shield Volcano

Answer 34

Low and wide, gently sloping dome or "inverted shield shape" composed of layers of lava. -This makes for a stronger structure less prone to failure