cram sesh

STORY OF EVERYTHING

Big Bang

Beginning of the universe
NOT an explosion
Rapid expansion from an infinitely hot, dense point
Universe still expanding today
Supported by:
- Cosmic Microwave Background Radiation
- Expansion of universe
- Oldest stars

Universe age:

13.7–13.8 billion years

Nebular Hypothesis

Explains formation of:

Sun
Planets
Solar System

Sequence

Solar Nebula

↓

Gravity

↓

Dust collides

↓

Bigger objects form

↓

Planets

↓

Solar System

Giant Impact Theory

Mars-sized object struck Earth

↓

Debris entered orbit

↓

Gravity pulled debris together

↓

Moon formed

Evidence:

Moon rocks have chemistry similar to Earth's.

Uniformitarianism

"The Present is the Key to the Past."

Modern geologic processes operated the same way in the past.

Founder:

James Hutton

Catastrophism

Old belief:

Earth formed by sudden catastrophic events.

James Ussher

~6000 year old Earth

NATURAL HAZARDS

Hazard

Potential danger

Disaster

Actual damaging event

Hazard ≠ Disaster

Professor says this MANY times.

Great Natural Disaster

Requires outside/international assistance.

Risk Assessment Steps

Identify hazard
Determine magnitude
Determine frequency
Determine recurrence interval
Identify people/property at risk
Determine mitigation

Mitigation

Action that reduces future damage.

Examples

Better buildings
Evacuation routes
Flood channels
Earthquake engineering

Engineering Controls

Reduced deaths from

Floods
Droughts
Earthquakes

Even though disasters increased.

Human Population

Current population

≈8 billion

Growth rate

≈1%

NOT exponential anymore.

Demographic Transition

Stage 1

High birth

High death

↓

Stage 2

Birth stays high

Death drops

↓

Rapid population growth

↓

Stage 3

Birth drops

↓

Population levels off

Carrying Capacity

Maximum population environment can support.

J-Curve

Unlimited resources

Exponential growth

S-Curve

Growth slows

Population reaches carrying capacity

Epidemic

Disease spreads rapidly.

Pandemic

Disease spreads internationally.

EARTHQUAKES

Earthquake

Sudden release of stored strain energy.

Stress

Force

Strain

Deformation

Compression

↓

Reverse Fault

Tension

↓

Normal Fault

Shear

↓

Strike-slip Fault

Joint

No movement

Fault

Movement

Focus

Underground origin

Epicenter

Point directly above focus

Fastest wave

P-wave

Compressional
Travels through solids & liquids

S-wave

Shear
Travels ONLY through solids

Love Wave

Side-to-side

Rayleigh Wave

Rolling

Surface waves

Most destructive

Magnitude

Energy released

Intensity

Damage observed

VOLCANOES

Magma

Underground

Lava

Surface

Viscosity

Resistance to flow

Higher silica

↓

Higher viscosity

↓

More trapped gas

↓

More explosive

Lower silica

↓

Lower viscosity

↓

Runny lava

↓

Gentle eruptions

Shield Volcano

Hawaii
Basalt
Low silica
Low gas
Gentle slopes

Composite Volcano

Mt. St. Helens
High silica
High gas
Explosive

Cinder Cone

Small

Steep

Loose volcanic fragments

Crater

Small summit depression

Caldera

Large collapse depression

Fumarole

Gas vent

Pyroclastic Material

Ash

Dust

Bombs

Blocks

Cinders

Aa Lava

Rough

Jagged

Pahoehoe

Smooth

Ropey

TSUNAMIS

Tsunami

Long wavelength wave

Most caused by

Subduction earthquakes

NOT caused by shaking.

Caused by

Vertical displacement of seafloor.

Professor repeats this.

Can also be caused by

Landslides
Volcanoes
Meteor impacts

Tsunami means

Harbor Wave

Most occur

Pacific Ocean

Ring of Fire

Deep ocean

Small wave height

Hard to notice

Near shore

Wave slows

Height increases

Warning sign

Ocean rapidly recedes

Run-up

Highest elevation reached

Inundation

How far inland water travels

Fetch

Distance wind blows over water

Wind Wave Size

Controlled by

Wind speed
Duration
Fetch

⭐ THINGS YOU ABSOLUTELY MUST MEMORIZE

Hazard ≠ Disaster
Joint ≠ Fault
Focus ≠ Epicenter
Magnitude ≠ Intensity
P-wave before S-wave
P-wave through liquids
S-wave cannot
Love = Side
Rayleigh = Rolling
High silica = High viscosity
High viscosity = More gas
More gas = Explosive volcano
Shield = Hawaii
Composite = Mt. St. Helens
Aa = Rough
Pahoehoe = Smooth
Tsunami = Harbor wave
Tsunami caused by seafloor displacement
Uniformitarianism = Present is key to past
James Hutton = Father of modern geology

PROFESSOR TRAP QUESTIONS

These are the kinds of questions I think Professor Field is most likely to ask because he emphasizes these distinctions in the lectures.

Is every natural hazard a disaster?
Is every disaster preceded by a hazard?
Does earthquake shaking itself produce a tsunami?
What actually moves to create a tsunami?
Can P-waves travel through liquid?
Can S-waves?
Which arrives first?
Is the epicenter underground?
Is the focus on Earth's surface?
Is a joint the same as a fault?
Which wave causes rolling?
Which causes side-to-side shaking?
Which volcanic setting produces Hawaii?
Which produces Mt. St. Helens?
Does high silica make lava runnier?
Which lava traps more gas?
What does viscosity measure?
Is magma above or below ground?
What is lava called underground?
Is Aa smooth?
Is Pahoehoe rough?
Which volcano type is the largest?
Which is most explosive?
What is the difference between run-up and inundation?
Why are most tsunamis in the Pacific?
What does Uniformitarianism mean?
What evidence supports the Big Bang?
How old is the universe?
How old is Earth?
Why has the number of disaster deaths generally decreased even as disasters have increased?