Week 4, Chpt 5

Question 1

Horizontal compression drives

Answer 1

collision.

Question 2

Horizontal tension drives

Answer 2

crustal rifting.

Question 3

Stress is when

Answer 3

pressure is equal on all sides.

Question 4

3 Types of Plate Boundaries

Answer 4

Dip-slip faults
Strike-slip faults
Oblique-slip faults

Question 5

Anticlines

Answer 5

A shaped folds

Question 6

U shaped folds

Answer 6

Synclines

Question 7

Monoclines

Answer 7

Folds at a mountain range edge

Question 8

Joints

Answer 8

Cracks in the rocks, they run parallel to each other. These are not faults.

Question 9

When a joint fills up with mineral it is called a

Answer 9

vein.

Question 10

How are mountains built? (4 ways)

Answer 10

Continental collision
Convergent boundaries
Continental rifting
Delamination

Question 11

Isostacy

Answer 11

Surface elevation is a balance between forces of gravitational attraction and buoyancy. The crust is floating on the mantle.

Question 12

Tearing the continent apart, the continent gets thinner.

Answer 12

Continental rifting

Question 13

Delamination

Answer 13

As the mantle gets cold the lithosphere gets thicker and denser. The mantle underneath the continent breaks off and sinks, causing the crust above it to rise.

Question 14

Stress (equation)

Answer 14

Force divided by area.

Question 15

Strain

Answer 15

Deformation expressed as a fraction of original body geometry.

Question 16

3 products of eruptions

Answer 16

Lava flows
Pyroclastic debris
Gas

Question 17

Basaltic lava flow

Answer 17

Low viscosity
Little silica
Very hot

Question 18

Columnar jointing

Answer 18

Rock shrinks as it cools, lava flows contract and fracture into polygonal columns.

Question 19

Andesitic and Rhyolitic lava flows

Answer 19

High silica content
Very viscous
Rhyolitic is the most viscous

Question 20

Effusive eruptions

Answer 20

Lava pours out of a vent or fissure after being squeezed upward due to pressure. It’s not viscous so it fills a lake around the crater and/or flows in molten rivers for great distances.

Question 21

Explosive eruptions

Answer 21

When pressure builds it results in an explosion.

Question 22

Oceanic hot spots create what kind of volcanoes?

Answer 22

Shield volcanoes.

Question 23

Continental hot spots and rifts produce

Answer 23

both effusive and explosive eruptions.

Question 24

If a rock has deformed by faulting this is an indication that the deformation occured

Answer 24

in the brittle regime.

Question 25

Energy release happens where?

Answer 25

Along faults.

Question 26

Plates are sliding by each other. Along the ____ you get ______. The rocks ____ and eventually ______. When they snap that energy is released in _____.

Answer 26

Plates are sliding by each other. Along the fault you get deformation. The rocks bend and eventually snap. When they snap that energy is released in waves.

Question 27

Magnitude scales are

Answer 27

logarithmic. Magnitude goes up by a factor of 10.

Question 28

Moment magnitude

Answer 28

Amount of energy released from an earthquake.

Question 29

Hypocentre

Answer 29

Focus. The location where fault slip occurs.

Question 30

Epicentre

Answer 30

Located on the surface directly above the hypocentre/focus.

Question 31

Shaking leads to

Answer 31

resonance.