Earth 20 Final

Tsunami

Japanese word with the English translation Harbor wave

Tsunami is Abnormally large waves generated

by any disturbance that displaces a large water mass from its equilibrium position (e.g., sea level).

What causes tsnuamis

Earthquakes that displace seafloor

steps of tsunami

Initiation
Split
Amplification
Runup

Description of tsunami Waves

Crest, amplitude, trough, wavelength

Trough

location of maximum deviation below the equilibrium position

Wavelength

distance between crests (or between troughs)

Amplitude

height of crest, or trough (also one half)

Tsunami Hazard in Santa Barbara

Offshore submarine landslides
Thrust faults in the SB Channel
Historic tsunami in 1812

What is mass wasting?

General term to describe the movement of rock or soil downslope under the influence of gravity
Landslides, debris flows, lahars, rock falls, soil creep, and slumps are all examples of mass wasting. Classification depends on mode of failure and material and or flow properties
Can be caused by other natural hazards
Earthquakes, volcanoes, storms, fires etc

What causes landslides?

Landslides result from slope failure or the inability for slope to remain stable and counteract the force of gravity
Slope stability decreases when
Mass is added high on s slope (eg., sediment, water)
Surface slope is stipend (eg. through fault motion, urbanization)
Support low on a slope is removed (e.g., river incision, wave erosion)

La Conchita Landslides

La conchita

Weather

= response of earth system (ex

Climate

regional/global distribution of temperature, precipitation, and storm patterns
Long term average of weather conditions
Both weather and climate are driven by heat energy at earth's surface and in atmosphere

Heat energy

energy associated with the random motion of atoms/molecules

Two kinds of heat energy

Latent heat and Sensible heat

Sensible heat

heat that can be measured (i.e.e, when you take the temperature of something)

Latent heat

heat energy absorbed or released during a phase change (e.g., liquid to gas)

Large amount of latent heat energy is stored by

water vapor in atmosphere

Heat transfer processes

conduction= heat transferred between two bodies due to being in contact with each other
Convection:

How does Earth get heat energy?

Radiated heat energy from electromagnetic waves emitted by the sun (ex

High albedo (closer to 1) =

high reflection

Low albedo (closer to 0)=

high absorption

Temperature depends on the degree to which radiation is relfected or absorbed

Reflects radiation (i.e. heat( = cools down
Absorbs radiation- warms up

Heat in the Atmosphere

Gasses in the atmosphere can absorb certain wavelengths of radiation, while reflecting or transmitting others
Greenhouse effect results in warming of the atmosphere
Variations in air temperature drive variations in density and pressure, which results in the movement of air (i.e. winds)

Warm air is less dense than cold air

it rises while cold air sinks

Air moves from high pressures to

low pressures

Winds near the poles generally blow

from east to west

Winds near the equator also generally blow

east to west

Mid latitude winds generally blow from

west to east

Greenhouse effect
GHGs

In the Troposphere and Mesosphere →

temperature decreases with altitude

On the stratosphere and thermosphere →

temperature increases with altitude.

Severe Weather

Includes:
Thunderstorms
Tornadoes
Hurricanes
Blizzards
Ice storms
Mountain windstorms
Heat waves
Dust storms
Severe weather is hazardous because it can release large amounts of energy that can cause damage
Eg

Thunderstorms

Warm air rises (sometimes due to a front) and water vapor condenses (clouds and rains). This releases latent heat energy, warming the air, which leads to continued rising (updraft)
As updraft continues, more water vapor condenses and forms rain, and possibility hail Falling rain generates a downdraft
Downdraft blocks the upward supply of moist air, warm air cannot rise further, and the thunderstorm weakens

Tornadoes

Most form in supercells (extreme thunderstorms)
Windshear near the ground causes air to rotate about a horizontal axis
Updraft from the thunderstorm formations lifts rotating air and orients it so it rotates about a vertical axis, causing the storm to rotate and forming a mesocyclone, which turns into a funnel cloud (AKA a Tornado before it reaches the ground)
Measured using the enhanced Fujita Scale (EF Scale)

Hurricanes
Recipe

Hurricanes

Measured using the Saffir- simpsons scale based on wind speeds, with category 5 being the strongest/ most impactful and category 1 as the slowest
← US hurricane season runs from june through Nov. Florida, louisiana

Age of Earth

4.567 Ga

Great Oxidation event

2.5 Ga

mass extinction

65 Ma -

Mass Extinction Events

Permo-triassic

Cretaceous- Paleogene

Most studied

Atmospheric composition

Study of Past Climates

Instrumental records

Keeling Curve

Carbon dioxide measurements

Climate Change Implications

Glacial receding/ ice caps melting → increased sea level rise → increased warming (think albedo)
Increased frequency and intensity of storms (hurricanes, tornadoes, etc)
Droughts
Wildfires risk (hotter fires than buen for longer
Biodiversity loss as animals migrate to higher altitudes to avoid increasing temperatu
Ocean acidification

Describe the Carrington Event

• most intense geomagnetic storm in recorded histroy (1959, solar cycle 10)
• formed global auroras (super bright) and fires
• result of a coronal mass ejection from the sun
• telegraph systems failed everywhere (another event like this would lead to major blackouts and damage of electrical power grids, would cost $3.6 trillion)

Describe the dinosaur-killing asteroid impact

66 million years ago
was 10 km wide
traveled 18 to 53 km/second
resulted in major tsunami

How powerful was the Tonga earthquake

M. 8.0, 2009

How is mass wasting gravity induced

• rapid downslope movement of earth materials as coherent mass
  triggered by other events such as earthquakes or volcanoes

Describe the Oso landslide

Oso, Washington
Landslide after rainfall

• weak glcial sediment atop slit and clay
• steep slope undercut by stream
• over $10 million in property damage
• $32 mil towards recovery
• 43 deaths (many landslides on some slope before), 49 homes

What was the laregest man made hole on Earth

• Located in a Utah mine
• led to largest non volcanic landslide
• 65 million m^3, 165 million tons, 3 km runout
• predicted successfully
  -shearing along discontuity= this sediment layer within stronger quarzite

Where are landslides most liekly to occur in th US?

along the west coast

• high incidences throughout the east (not coast, more inwards)

What are the main effects of lanslides

• significant damage
• impede travel and bloack syreams- flooding
• disease= spores kicked up
• earthquakes, volcanoes, storms, and fires cause them
• lead to flooding or tsunamis

How do you reduce slope stability

• adding mass high on slope (daylighting layers)
• steeping slope
• removing support from low on slope

What are instances of human interaction with landslides?

• Urbanization and development
  -clear-cutting of forested areas + removing vegetation
  transportation networks
• grading of land surfaces
• over steeping slopes
• lawn irrigation + septic systems

How can landslides be minized?

• Identify landslide- prone areas (hazard maps)
• warning systems
• stablizing structures
• movements of critcal facilites (hospitals, schools, police stations)
• improving drainage
  -avoid development at high risk sites.

How can we see where landslides may occur?

• creep-y= slow downard movement
• bent trees
• evidence of mass wasting (clear there was previous slide, use common sense)

What does drainage control look like

What is grading as a means of landslide minization?

• increases slope stablity
• material from upper sloep moved to base (think benches)

What are slope supports as a means of landslide minization?

retaining walls such as concrete or filled were baskets

What happened after La Conchita experienced a landslide in 1995

• Elaborate dewatering systems and benches would cost $150 million
• too expensive, so modest wall and limited drainage system established (proved ineffective in 2005)

What were the effects of second landlside in La Conchita?

In 2005, after 15 days of rainfal

• highly fluid debris flow
• killed 10 people, destroyed 13 houses, and damaged 23 others
  -remobilzed 1995 landlside material

Describe santa barbra landslide risk

• currently criscrossed with faults
• ancient debris flow nearby
• may transport 4 km, thickness 2-6 m in the canyon

Describe one of the recent major fires

thomas fire (2007) burned hillsides above montecito (record setting)

• followed by a rare 200-300 year rainstorm

describe the steps of a debris flow

1. acculation of debris in canyon (hundreds of years)
2. wildfires that forms water replient soil
3. intense precipitation that occurs every few hundred years, leads to debris flows

• always rare events

What is potential energy

stored energy

What is kinetic energy?

Eergy of motion

Latent heat solid to gas=

energy absorbed

Latent heat gas to liquid=

energy released

What is conduction

Two bodies in contact with each other

What is convection

Transder through mass movement of a fluid

WHat is radiation?

Electromagnetic waves

Describe the different types of radiaation on the electromagnetic spectrum

Infrared, vissible, UV, Outgoing, incoming

Infrared

outgoing longwav radiation from the sun

visible

what we can see

UV

precedes visbile

Outgoing

almost all radiation

incoming

visible, uv, some infrared

What are the methods that occur when energy from the sun reaches Earth?

• redirection
• transmission
• absorbtion

Describe redirection of energy

• reflection back to space by clouds, water, land (volcanic aeorsols)
• scattering reflection in many directions

describe transmission of energy

• energy passed through atmosphere without change.

• describe transmission of energy

• energy passed through atmosphere without change

describe absoirption of sun energy

• alters milecules or causes them to vibrate
• possivle re emission to space

Describe the aborption as a means of energy behavior

• energy not reflecred is absorbed
• different objects absorb different wavelengths
• gasses are very selective (absorb some wavelengthm not others)
• hotter objects emit ebergy more rapidly and at shorter wavelengths
• temperature depends on degree of relfection and absorption of radiation

Describe the greenhouse effect and reflection

• half of the suns radiation is aborbed by the earths surface
• some is reflected by the atmosphere
• some passes through the atmosphere ack into space
• some is absorbed and re emitted by greenhouse gas molecules

Describe the greenhouse gasses impact on the atmosphere

• without these molcules, infrared heat would only be radiated back into space
• without them earth would freeze
• however, too much leads to global warming
• too little= mars, too much venus

describe tropshere

• where we live
• includes weather, clouds, etc
• temp decreases with increasing altitude (besides the stratosphere where temps increase)

Air pressure =

Barometric pressure

what aspects directly related to severe weather?

• Atmospheric pressure and circulation patterns
• vertical stability of the atmosphere
• coriolis effect
• interaction of different air masses

Describe horizontal pressure changes

• due to changes in air temperature and air movement
• variations in temperature lead o winds
• polar air is cold and dense
• equatorial air is warm and less dense

describe the coriolois effect

• air is defleccted to the right in the north, and deflected leeft in the south
• however, trade winds in the middle move west, and westerlies near the poles move east (counter clockwise)

where do thunderstorms primarily occur?

The southeast of America, more outwards from there

what do thunderstorms need to form

1. equatorial (not artic)
2. afternoons/evenings (not mornings or nights)
3. spring or summer
4. forms along cold fronts (warm plowing under warm air)

Three stages of thunderstorms

1. rising warm causes condenstaiton of vapor (latent heat released)
2. heavy rain, lightning and thunder, hail
3. downdraft blocks upward supply of moist air (it then weakens)

What are environmental conditions required for thunderstorms?

• updraft of moist air that transitions into dryer air higher in the atmosphere
• changes in veritcal wind shear

What are supercell storms

• upward spiraling column of air (mesocylone)
• exteremly violent, lead to tornadoes
• last from 2 ot 4 hours

How do supercell storms and tornadoes form?

• windsheat develops horizontally faster than slow winds
• updrift begins and inverts the wind shear system
• wind shear then is vertical (latent heat adds to updraft)

What is wall cloud?

The rear lower part of cumulonibus clouds