Eosc 114 Midterm 1 Review

Front 1

What is a disaster?

Back 1

Substantial event causing

1) physical damage

2) injury or loss of life

3)a drastic change to the environment

Front 2

What is an element?

Back 2

A chemical element consists of identical atoms

Front 3

What is in an atom?

Back 3

Protons (+), neutrons in the nucleus, Electrons (-) orbit

Front 4

How can you tell the number of protons in an atom?

Back 4

Atomic #

Front 5

What elements, in order of adundant mass, is the earth's crust made of?

Back 5

oxygen, silicon, aluminum

Front 6

What elements, in order of adundant mass, is the earth's core made of?

Back 6

iron, nickel, oxygen?

Front 7

What elements, in order of adundant mass, is the ocean made of?

Back 7

oxygen. hydrogen, chlorine

Front 8

What elements, in order of adundant mass, is the atmosphere made of?

Back 8

nitrogen, oxygen, argon

Front 9

What are the characteristics of each phase of matter?

Back 9

Solid: not very fluid, not very compressible

Liquid: very fluid, not very compressible

Gas: very fluid, very compressible

Front 10

What is the formula and units for density?

Back 10

D=mass/volume

kg/m^3

Front 11

Define stratification

Back 11

less dense materials float on top of denser materials, creating stratification

Front 12

Give the stratification of the earth

Back 12

atmosphere, ocean, crust, mantle, outer core, inner core

Front 13

What is a force?

Back 13

something that pushes or pulls, measured in Newtons

Front 14

What is work?

Back 14

The force that pushes an object times the distance the object moves

Front 15

What are the 4 types of energy?

Back 15

potential, kinetic, sensible, latent

Front 16

What is potential energy? Give an example of an object with PE

Back 16

The work needed to raise an object of (m in kg) mass a vertical distance (z in meters) against the pull of gravity

PE=g.m.z

eg. holding a pineapple in the air

Front 17

What is kinetic energy? Give an example of KE

Back 17

energy from moving

KE=0.5 x m x v^2

eg. a car rolling on the road

Front 18

What is sensible heat? Give an example

Back 18

heat energy we can sense, feel, or measure

ie. when we measure temp we are measuring sensible heat

Front 19

What is latent heat? Give an example

Back 19

"hidden" energy in chemical bonds stored between atoms

sensible heat stored as latent heat during melting or boiling (sublimation)

latent heat released as sensible heat hen condensing or freezing (depositing)

Front 20

Describe what happens to latent heat when gas becomes liquid

Back 20

heat is transferred/released to its surroundings

Front 21

Describe what happens to latent heat when liquid becomes gas

Back 21

heat is taken from the surroundings

Front 22

What is an order of magnitude?

Back 22

powers of ten

Front 23

What is the logarithmic scale

Back 23

steps by powers of ten, eg. "3" is 10^3

Front 24

Name 3 order of magnitude scales

Back 24

Richter Scale (Earthquakes)Moment Magnitude Scale (Earthquakes)Volcano Explosivity IndexBeaufort Scale (Wind and Waves)Saffir‐Simpson Scale (Hurricanes)Enhanced Fujita Scale (Tornadoes)Torro Scale (Tornadoes)Torino Scale (Impacts)

Front 25

What is return period?

Back 25

average number of years between disaster events of the same magnitude

Front 26

Calculate the RP of a category 5 hurricane that has occured 2 times in 70 years

Back 26

RP (5)=time span of data/number of times it has occured

RP=35

Front 27

Name the time scale for energy and release time for earthquakes

Back 27

centuries/years --> minutes

Front 28

Name the time scale for energy and release time for volcanoes

Back 28

centuries/decades --> days

Front 29

Compare risk and hazard

Back 29

Hazard is any event that could cause human or economic harm and risk is the probability that a hazard will occur

risk=hazard x vulnerability

Front 30

Describe population growth and explain why it is important for natural disasters

Back 30

population exceeds carrying capacity,with more people infrastructure becomes more important nd vulnerable and people are less likely to be evacuated

Front 31

what is carrying capacity

Back 31

the population that can be sustainably developed in a certain domain

Front 32

What is vulnerability

Back 32

a weakness that could be affected by a disaster and or how badly it could be affected

Front 33

True or false: our perception of risk is accurate and helpful

Back 33

false

Front 34

List the components of the earth from outer to inner layers. Also give their relative temperatures

Back 34

Crust (cold), mantle (warm), Core (hot)

Front 35

What component of the earth are tectonic plates made of?

Back 35

solid crust and upper part of the mantle, the lithosphere

Front 36

What is the theory of plate tectonics

Back 36

theory developed by Alrfred Wegner, study of how the plates evolve and move on the surface. poposed that continents drifted through the ocean

Front 37

Describe the Unifying theory of earth's dynamics

Back 37

the fundamental process that controls the earth's structure and evolution

Direct cause of many hazards e.g. earthquakes, volcanoes, tsunamis

Responsible for the topographic features such as continents, mountain belts

Front 38

What controls plate tectonics?

Back 38

Physical properties: composition, density, temperature

Force: gravity

Front 39

What affect does temperature have on density?

Back 39

it causes density to decrease

Front 40

What is rheology

Back 40

how a material deforms

Front 41

Describe the 3 types of deformation

Back 41

ELASTIC: springs back and is reversible; DUCTILE: plastic flow and is permanent; BRITTLE: breaks and is permanent

Front 42

Describe the rheology of the lithosphere

Back 42

Lithosphere (crust and uppermost mantle)

Cool, solid, exterior shell

Brittle….but sometmes ductle

Front 43

Describe the rheoloy of the aesthenosphere

Back 43

Hotter and deeper, very ductile (geological time), almost melting but still solid

Front 44

Describe the rheology of the mesosphere

Back 44

lower mantle, hotter but very high pressure, solid, stiff but ductile (geological time)

Front 45

Describe the rheology of the outer core

Back 45

metalic, extremely hot, very high pressure, liquid

Front 46

Describe the rheology of the inner core

Back 46

metalic, even hotter and even more pressure, solid

Front 47

Where on a plate is an earthquake most likely to happen?

Back 47

on the boundary

Front 48

What are the 2 types of crust? Describe each

Back 48

Continental crust: variable but felsic(granite), thick, relatively less dense

Oceanic crust: Mafic, thin, relatively more dense, "floats low"

Front 49

What are the 2 types of plates

Back 49

Continental Lithosphere: beneath yellowknife is the oldest and coldest

Beneath vancouver it is hot and relatively thin

Oceanic Lithosphere: at a ridgecrest, it is youngest and hottest

Northeastern pacific is the oldest and coldest

Front 50

Describe the convection cycle in the context of the earth

Back 50

Plate tectonics is the upper layer that floats on top of the convection cycle

the mantle and the oceanic lithosphere rise and cool, then sink and heat

Front 51

How much do plates move on average per year?

Back 51

3-4 cm

Front 52

What are 3 forces acting on plates

Back 52

basal drag, slab pull, and ridge push

Front 53

Define basal drag

Back 53

friction between rigid lithosphere and the more ductile asthenosphere drags the plate along

Front 54

Define slab pull

Back 54

cold descending plate is denser thanthe hot mantle

gravity pulls dense plate down

Front 55

Define ridge push

Back 55

heating at the rift raises the ridge crest

gravity pulls the elevated plates downand apart

Front 56

What are the general plate boundaries, what action do they usually do, what forces typically act on them, and what fault are they usually associated with?

Back 56

1. convergent, two plates push together, compression, thrust/reverse

2. divergent, two plates pull apart, tension, normal

3. Transform, two plates slide past each other, shear, strike slip

Front 57

Which way does the hanging wall slide in each type of fault

Back 57

Normal: down, reverse: up, strike slip: horizontal

Front 58

Rate the boundaries based on strength from strongest to weakest

Back 58

convergent, transform, divergent

Front 59

How can you link faulting and earthquakes to the different plate tectonic boundaries?

Back 59

a) Temperature, strength, and geometry are keys todetermining if or how ‘big’ a brittle fracture(earthquake fault rupture) will be.

b) You can logically predict for any plate boundary:• The type of faulting that would dominate there.• Where the earthquakes would happen in/near thatboundary.• How ‘big’ the earthquakes would likely be.

Front 60

Give the stats on divergent plate boundary earthquakes. Include Force/fault, depth range, max size, frequency of quakes, locations, and risk

Back 60

tension/normal, very shallow due to hot thin lithosphere, not very big quakes, frequent, mid ocean ridges (eg mid atlantic ridge), low risk

Front 61

Name the types of convergent plate boundaries

Back 61

subduction and collision

Front 62

Why do only oceanic plates subduct?

Back 62

continental crust is too buoyent

Front 63

If two continental plates converge, which one subducts?

Back 63

the oldest one

Front 64

Give the stats on subduction plate boundary earthquakes. Include Force/fault, depth range, max size, frequency of quakes, locations, and risk

Back 64

compression/thrust reverse, three zones (0 to 650km), biggest because the lithosphere is cold and strong and is under compression, max 9.7 Mw, very infrequent, occurs in 3 zones 1) plate interface (megathrust 25-40 km depth) 2) overriding plate (up to ~50 km depth) 3) Downgoing slab (up to 650 km depth), risk depends on pop density and distance from hypocenter

Front 65

What happens when there is continent-continent collision

Back 65

plates fuse building mountains, crust thickens, and very large earthquake occcurs

Front 66

Give the stats on continental collision earthquakes. Include Force/fault, depth range, max size, frequency of quakes, locations, and risk

Back 66

compression, undr 200 km, high potential for mega earthquake, low frequency, broad width of zone well back into overriding plate, high risk

Front 67

Where do subduction earthquakes occur?`

Back 67

3 zones

1) plate interface (megathrust 25-40 km depth)

2) overriding plate (up to ~50 km depth)

3) Downgoing slab (up to 650 km depth)

Front 68

Give the stats on transform plate boundary earthquakes. Include Force/fault, depth range, max size, frequency of quakes, locations, and risk

Back 68

shear, shallow, narrow, potential for major earthquake 8Mw, can be infrequent, risk depends on location

Front 69

Elastically, what is an earthquake

Back 69

the elastic rebound to the original shape (diff posiiton) after cool brittle rock breaks

Front 70

Contrast the types of seismic waves

Back 70

body waves travel inside the earth and suface waves travel on the boundaries between materials

Front 71

Discuss the 2 types of body waves

Back 71

P wave: • compression and extension of the solid (or fluid), like a sound wave • particles move in same direction wave propagates • fastest type of seismic wave: about 6 km/second in continental crust

S wave: • shearing distortion of the solid • particles move perpendicular to direction wave propagates • slower than P wave: about 3.5 km/second in continental crust. Cannot pass through fluids!

Front 72

True or false: surface waves are slower than body waves

Back 72

true

Front 73

discuss the types of surface waves

Back 73

Rayleigh wave: vertical and horizontal motion parallel to wave travel direction (like an ocean wave)

Love wave: horizontal movement perpendicular to wave travel direction

Front 74

How can you use triangulation to determine the location of the hypocenter

Back 74

We can use the time between P and S waves using at least 3 seismometers to triangulate location

Front 75

What is the difference betwen magintude and intensity

Back 75

magnitude: how much energy was released

Intensity: how strong the ground motion was felt by the location

Front 76

What are the two scales for measuring magnitude

Back 76

1) local or richter magnitude: based on the ground motion, usually the surface wave amplitude

2) moment magnitude: based on area of rupture and slip on fault, now the standard

Front 77

For each increase on the magnitude scale, how much does the energy increase by

Back 77

32 times

Front 78

What is the hypocenter

Back 78

point on the fault, usually below the surface, where the rupture starts

Front 79

For each increase in magnitude, how much does the shaking increase

Back 79

10 times

Front 80

What is the epicenter

Back 80

the point directly above the hypocenter on the surface

Front 81

What scale is intensity measured on?

Back 81

Mercali scale, based on percetion not qunatitative data

Front 82

Which is more damaging: horizontal or vertical shaking

Back 82

horizontal

Front 83

Which waves are the most damaging? which are the least damaging?

Back 83

Surface waves:•Often the largest amplitudes•Rolling motion most destructive•Duration is the longest.

P (compressional) waves:•Often the smallest amplitudes•Near-vertical ground motion is the least destructive•Duration is the shortest.

Front 84

What type of ground is most destructive

Back 84

the wetter and looser the soil, the more problematic

Front 85

What material is the most safe for houses

Back 85

wood

Front 86

What type of building has the most resonance

Back 86

Short, squat, low mass buildings tend to be sSffer • Resonate at high frequencies, fast vibraSons with low amplitudes

Tall, skinny higher mass buildings tend to be more flexible • Resonate at low frequencies, slow vibraSons with large amplitudes

Front 87

What are some measures engineers can take to prevent resonance disasters

Back 87

• Tuned mass dampers Massive pendulum within a building is designed to counter the building sway and resonance from earthquakes or wind

• Seismic base isolation systems Structural elements that decouple the building from its base

Front 88

Why do water saturated sediments lose strength during an earthquake?

Back 88

During an earthquake: • The vibrations wiggle the grains around • Increasing the water pressure in the pore spaces • This pushes the grains apart • Contact forces decrease and the grains and water can move more easily • The sediment ‘liquefies’