Exam 4 Vocab/Notes

Albedo

measurement of reflectance

Snow and ice have high albedo so they resist warming

Carbon dioxide

Mechanical/Physical Weathering

• Frost wedging

• Salt Crystal Growth

• Sheeting

• Biological activity

Humus

Soil Erosion

Snow Line

Till

Plucking

Glacial Eratic

Glacia retreat

Fall

Scarp

Longwave Radiation

Radiation emitted by Earth is absorbed by gases in the atmosphere

• Such as carbon dioxide and water vapor

Greenhouse Gas

Chemical Weathering

1) Oxidation

• Oxygen dissolves in water

• Minerals oxidize or rust

2) Carbon acid

• Carbon dioxide dissolves in water

• Co2 + H2o → H2CO3

• H2CO3 → H+ + HCO3-

Topsoil

Dust Bowl

Firn

Zone of accumulation

Rock flour

End moraine

Positive Feedback loop

Slide

Rockslide

Shortwave Radiation

solar radiation passes through the atmosphere and heats the Earth

Atmospheric Window

Frost Wedging

O horizon

Biological activity

Zone of wastage

Tillite

Crevasse

Glacial budget

Mass Wasting

Creep

Rockfall

Greenhouse Effect

Heating the atmosphere

• long-wave radiation heats the atmosphere, whoch radiates heat both out into space and back to Earth.

• This selective absorption and reheating of Earth is called the greenhouse effect and results in warming of the atmosphere

Climate vs Weather

Weather:

• instantaneous atmospheric condition

• Can change rapidly

• Prevails over a short area

• Only limited predicability

• depends primarily on density (temperature and moisture) differences between one place and another

Climate:

• average atmospheric conditions

• sustains over 30 years

• prevails over a large region

• is almost constant

• depends on latitude, distance to the sea, vegetation, presence or absence of mountains, and other geographical factors

Climate is what you expect, weather is what you get

Carbonic acid

A horizon

Oxidation

Ice sheet

Zone of fracture

Alpine glacier

Glacial advance

Angle of repose

Slump

Earthflow

Absorbed →

causes warming

Reflected →

no warming

Solar Energy =

short wave radiation

Grenhouses Gases

1. Water vapor, H2O

2. Carbon Dioxide, CO2

3. Methane, CH4

4. Nitric Oxide, NO2

5. Ozone, O3

6. Hydrocarbons

7. Chlorofluorocarbons

Non-Greenhouse Gases

1. Nitrogen, N2

2. Oxygen, O2

3. Argon, Ar

4. Carbon Monoxide, CO

5. Sulfur Dioxide, SO2

Greenhouse Effect

• Natural

• Would still be operating in the absence of human life

• necessary for our planet to be habitable

• Humans are changing how strong the greenhouse effect is by altering the amount of greenhouse gases present in the atmosphere

Climate and Soil Formation

• Tempature and precipararion most important

• Determines whether mechanical or chemical weathering predominates

  Determines the depth of soil formation:

• Warm, wet climates produce a tick layer of chemically weathered soil

• Cool, dry climates produce a thin layer of mechanically weathered soil

Paths of Incoming Solar Energy

• 50% of solar energy passes through the atmosphere and is absorbed on Earth’s surface

• 20% is absorbed by clouds and atmospheric gases

  • Including oxygen and ozone

• 30% is reflected back into space

  • By clouds, atmosphere, snow, and ice

Rising CO2 levels

• Carbon dioxide is a greenhouse gas

  • short-wavelength solar radiation passes through to Earth but slows long-wavelength Earth radiation from passing back into space

• Humans add CO2 to the atmosphere

  • Burning fossil fuels

  • Deforestation

• CO2 levels are highest in the past 600,000 years

Oxygen Isotope Analysis

• The precise measurement of the ratio of 18O/16O

  • Ratios are trapped in calcium carbonate shells or marine organisms

  • Ration varies with the amount of sea ice and water tempature

Climate change recorded in glacial ice

• Some ice cores represent more than 200,000 years of climate history

  • Ice can be analyzed for:

    a. Oxygen isotope analysis

    b. Carbon dioxide and methane (air bubbles trapped in the ice)

    c. Dust, volcanic ash, pollen

Tree Rings: Archives of environmental history

• Growth rings are added each year

  • The thickness and density of rings reflect environmental conditions

  • In certain regions, ring chronologies extend back thousands of years

Other types of proxy data

• Fossil pollen

  • Pollen can provide high-resolution records of vegetation changes in a region

    • Regional vegetation is climate-dependent

• Corals

  • With oxygen isotope analysis, corals are used as paleothermometers and precipitation proxies

Chemical Weathering

• water

• rain water and carbonic acid

Differential Weathering

Formations of Landforms

• Erosion cuts vertically down into rocks

• If streams alone were creating landform, the valley would be deep and very steep sided

• Mass wasting creates river valleys wider than they are deep

Mass Wasting

• Downslope movement of rock and soil under the direct influence of gravity

  • Can be fast or slow

  • Includes mudslides, lahars, landslides, rock avalanches, soil creep

Controls on Mass Wasting: Oversteepened slopes

• Consolidated soils or rocks can experience overstepping

• Steepness that can be maintained depends on the material present

• Won’t move immediately like unconsolidated material

• Will eventually lead to mass wasting & less steep slopes → restores stability

Controls on Mass Wasting: Removal of Vegetation

• Roots bind soil and regolith together

• Protect against raindrop impact and erosion

• Cutting down trees for agriculture

• Replacing deep-rooted plants with shallow-rooted plants

• Wildfires all increase the likelihood of mass wasting

Triggers of Mass Wasting Events: Addition of Water

• water foes not transport the material, but weakens cohesion

• “Lubrication’ of grains allows gravity to move the material more easily

• Adds weight to the sediments, increasing the effects of gravity

• Heavy rains, melting glaciers

Triggers of Mass Wasting Events: Oversteepened slopes

• Unconsolidated particles assume a stable slope at the angle of repose

  • different for various materials

• Natural processes, such as stream cuts, oversteepen a slope

Triggers of Mass Wasting Events: Earthquakes

• Conditions that favor mass wasting can exist for a long time before anything happens

• Shaking from an earthquake may trigger any kind of mass wasting event

• Intense shaking of water-saturated materials may cause them to behave like a liquid in a process known as liquification

Triggers of Mass Wasting Events

No specific Trigger

• Sometimes rapid mass wasting events happen with no discernible trigger

• Slope materials gradually weaken due to long-term weathering and the infiltration of water

• Eventually gives out and falls

• Process essential random and very difficulty to predict in terms of timing

Classification of Mass Wasting Events: Material

• Soil or regolith - Debris, mud, earth

• Bedrock = Rock

Classification of Mass Wasting Events: Motion

• Fall= free fall of detached pieces

• Slide= distinct zone of weakness

• Flow= move as a viscous fluid to create lobes or tongues

Classification of Mass Wasting Events: Rate of Movement

• Fast

• Intermediate

• Slow = Creep

Slump

• The movement of a mass of rock or unconsolidated material as a unit along a curved surface

  • can involve a single mass or multiple blocks

• Occurs along oversteepened slopes

• Moderate speed

Earthflow

• Earthflows form on hillsides in humid regions during heavy
  precipitation or snowmelt

• Commonly involve materials rich in clay and silt

• Create a tongue or teardrop-shaped mass that flows
  downslope

• Travel between 1 mm a day to several meters a day

• Commonly associated with large slumps