Lecture quiz 2

Question 1

GPS is used to determine?

Answer 1

latitude, longitude and elevation

Question 2

How is earthquake distribution proof of plate tectonics?

Answer 2

most earthquakes plate along plate boundaries (90%), by depths the deepest earthquakes occur at convergent plate boundaries at subduction zones

Question 3

Before GPS how were rates calculated

Answer 3

Rate= distance from mid-ocean ridge/ age of ocean floor

Question 4

Maximum plate movement/ year

Answer 4

16.5cm/yr

Question 5

What are the main causes of plate movement

Answer 5

convection in mantle, ridge push and slab pull(trench suction)

Question 6

Who was first to suggest convection and in what year?

Answer 6

Arthur Holmes 1928

Question 7

Explain steps in wilson cycle

Answer 7

supercontinent-> continental rift zones -> narrow seas -> new ocean with no subduction zones -> subduction develops -> old ocean with many subduction zones -> continents moving closer -> continents collide and back to supercontinent

Question 8

Types of earthquakes in Canada?

Answer 8

Eastern: ancient faults
Western: queen charlotte transform fault and faults in canadian rockies
arctic: transform plate boundary forming??(debated)

Question 9

What is an earthquake?

Answer 9

Vibrations of the earth produced by a rapid release of energy built up along the fault.

Question 10

What is a focus?

Answer 10

Point on the fault where first movement begins

Question 11

What is an epicentre

Answer 11

Point at the surface directly above the focus

Question 12

Types of faults involving earthquakes?

Answer 12

strike-slip (horizontal), dip-slip (vertical), oblique-slip (both)

Question 13

Explain elastic rebound

Answer 13

forces accumulate and cause eventual slip between plates

Question 14

Explain what a rayleigh wave is

Answer 14

Move the surface up and down as well as side to side (in direction of wave movement

Question 15

Explain what a love wave is

Answer 15

faster surface wave, deform surface side to side , shearing component, different blocks shift in different directions in proportion to each other, very destructive

Question 16

What is a seismograph?

Answer 16

record of ground movement

Question 17

How do you measure the distance to earthquake epicentre?

Answer 17

Circles are drawn at three locations with radiuses equal to distances. The point where three circles intersect is the epicenter.

Question 18

Formula for body wave magnitude?

Answer 18

Mb = log10(A/T) + Q(D,h)

Question 19

Formula for surface wave magnitude?

Answer 19

MS = log10 (A/T) + 1.66 log10

Question 20

Formula for moment magnitude scale?

Answer 20

MW = 2/3 log10(MO) - 10.7

Question 21

What are a couple things that affect the amount of damage that occurs from an earthquake?

Answer 21

building design, distance from the epicentre, type of surface material

Question 22

What is liquefaction?

Answer 22

When sediments become converted into suspension by ground shaking. Shaking increases pore water pressure, which causes quicksand conditions at the surface

Question 23

What is the earthquake cycle concept?

Answer 23

When stress buidup is associated with slow movement of plates during long periods of time. rocks along the fault have certain physical properties that allow them to accumulate only certain amount of stress before they snap resulting in earthquake
long major faults predict location and length of future fault rupture. The segments of the faults with no seismic activity for a long time are called locked. These segments are capable of generating strong earthquakes because stress on them has not been released

Question 24

How can magma be generated

Answer 24

addition of heat, decrease in pressure, and introduction of volatiles

Question 25

Three settings of igneous activity

Answer 25

divergent plate boundaries, convergent plate boundaries, hot spots

Question 26

What type of magma do divergent plate boundaries create

Answer 26

mafic

Question 27

What type of magma do convergent plate boundaries create

Answer 27

intermediate and felsic

Question 28

What type of magma do hot spots create

Answer 28

mafic and felsic

Question 29

Explosive volcanoes emit what type of magma

Answer 29

felsic and intermediate

Question 30

Effusive volcanoes emit what type of magma

Answer 30

mafic

Question 31

What type of factors cause an explosive eruption

Answer 31

Low temperature, high gas content and high viscosity

Question 32

What does an effusive eruption mean

Answer 32

river of very fluid lava

Question 33

What are the primary factors that determine the nature of a volcanic eruption

Answer 33

viscosity(temperature and silica content) and amount of dissolved gases

Question 34

What is pyroclastic material

Answer 34

pulverized rock and lava fragments blown from volcanoes vent which includes ash, pumice, lapilli, cinders, blocks and bombs

Question 35

Rocks formed from pyroclastic materials are called what

Answer 35

tephra

Question 36

Cemented ash particles form what

Answer 36

tuff

Question 37

Fused ash particles form what

Answer 37

welded tuff

Question 38

cemented particles larger than ash are called what

Answer 38

volcanic breccia

Question 39

Why is tephra useful

Answer 39

Tephra can be dated radioactively to obtain information about past earthquakes

Question 40

what is a pyroclastic cone

Answer 40

A relatively small volcanoe several metres high composed of pyroclastic materials

Question 41

What is an example of a pyroclastic cone

Answer 41

sunset crater

Question 42

What is a tuff cone and maar

Answer 42

They are broad, low relief craters that are caused by phreatic steam eruption

Question 43

What is an example of a tuff cone

Answer 43

hole in the ground

Question 44

What is a caldera and how is it produced

Answer 44

A caldera is a giant depression produced by summit collapse or subsidence

Question 45

What is an example of a caldera

Answer 45

crater lake

Question 46

What is a somma volcano and an example

Answer 46

new stratovolcanoes grow inside calderas, ex vesuvius

Question 47

Why are the deccan flood basalts in india important

Answer 47

May have played a role in the extinction of the dinosaurs. The gases produced by the eruption may have changed the global climate contributing to their demise

Question 48

List all volcanic hazards

Answer 48

Pyroclastic clouds, lava flows, gas emissions, lahars, steam explosions, tsunamis, earthquakes, volcanic landslides, climate effects

Question 49

List the effects of supereruptions

Answer 49

Volcanic winter, ecological catastrophe, climate change, disruption of air traffic and communications, acid rain and destruction of farmland

Question 50

How are scientists able to create long term predictions and short term predictions of volcanos

Answer 50

long term: previous eruptions and plate tectonics | short term: earthquakes, gas emissions, shape/ ground deformation and water acidity

Question 51

What are the two largest sources of fresh water

Answer 51

Glocial ice and groundwater

Question 52

What percentage of the earths hydrosphere is saline water

Answer 52

97%

Question 53

What is the largest river in terms of discharged water

Answer 53

amazon

Question 54

What are the types of erosion

Answer 54

erosion(hydraulic action, abrasion, solution)

Question 55

What are the types of sediment

Answer 55

bedload, suspended load, dissolved load

Question 56

Discharge formula?

Answer 56

D=VA

Question 57

What is the format of a hydrograph

Answer 57

xaxis: months/days yaxis: discharge

Question 58

What is a bedload

Answer 58

The largest particles, rolling and sliding along bottom(pushed by current), jumps to next position (saltation)

Question 59

the 4 examples of bedforms

Answer 59

1. transverse catenary ripples 2. plane stratification in beach sandstone 3. anti dunes in shallow water 4. dunes

Question 60

Explain braided streams

Answer 60

multiple channels seperated by sand and gravel bars

Question 61

Explain anastomosing streams

Answer 61

interconnected channels that rejoin

Question 62

What is anabranching

Answer 62

interconnected channel

Question 63

Causes of floods

Answer 63

ice dam failure, proglacial lake outflow, lake basin outlow, landslide dam faille, calera lake breach, failure of man made dams, rainfall, snowmelt and ice jam, storm surges

Question 64

What is the evidence of megafloods

Answer 64

giant current ripples up to 20m high developed within the deepest parts of the main outflow valleys created by glacial lake outburst floods

Question 65

What is a flash flood

Answer 65

very rapid increase in stream discharge caused by severe thunderstorms or dam collapse especially typical for desert area

Question 66

What is channelization

Answer 66

describes any activity that moves, straightens, shortens, cuts off, diverts, or fills a stream channel whether natural or previously altered