Earth Science Exam 4

Front 1

How much water is available to us?

Back 1

only get >1% is available to use for humans, and there are 7 billion of us...PLUS PLANTS AND ANIMALS

Front 2

Precipitation

Back 2

released form the atmosphere

Front 3

Evaporation

Back 3

absorbed into the atmosphere

Front 4

Infiltration

Back 4

soaks into the ground

Front 5

Runoff

Back 5

flowing over the surface

Front 6

Transpiration

Back 6

plants release into atmosphere

Front 7

Streamflow

Back 7

volume of water traveling a distance over time.

Front 8

Factors that determine velocity (distance/time)

Back 8

1. Gradient, or slope
2. Channel characteristics
Shape, Size, Roughness
3. Discharge – volume of water flowing in the stream (generally expresses as cubic feet per second)--

Front 9

Mass wasting

Back 9

the transfer of rock material downslope under the influence of gravity

Front 10

Erosion

Back 10

the incorporation and transportation of material by a mobile agent, usually water, wind, or ice

Front 11

difference between streamflow and discharge

Back 11

discharge is about specific stream (so diff from streamflow, which is general)

Front 12

Factors that: Increase downstream

Back 12

1. Velocity
2. Discharge
3. Channel size

Front 13

Factors that: Decrease downstream

Back 13

1. Gradient, or slope
2. Channel roughness

Front 14

2 kinds of weathering

Back 14

1. mechanical
2. chemical

Front 15

Mechanical Weathering

Back 15

• •Breaking of rocks into smaller pieces
Processes of mechanical weathering
A. Frost wedging
B. Unloading
C. Biological activity

Front 16

Chemical Weathering

Back 16

Alters the internal structures of minerals by removing or adding elements

Most important agent is water:

Oxygen dissolved in water oxidizes materials

Carbon dioxide (CO2) dissolved in water forms carbonic acid and alters the material

Front 17

3 Important factors that influence rates of weathering

Back 17

Rock Characteristics

climate

differential weathering

Front 18

Rock Characteristics

Back 18

• Mineral composition and solubility (Chpt 1)
• Physical features such as joints (Chpt 2)

Front 19

climate

Back 19

• Temperature and moisture are the most crucial factors
• Chemical weathering is most effective in areas of warm temperatures and abundant moisture

Front 20

differential weathering

Back 20

• Caused by variations in composition
• Creates unusual and spectacular rock formations and landforms

Front 21

soil

Back 21

An interface in the Earth system !

Soil is a combination of mineral matter, water, and
air – that portion of the regolith (rock and mineral fragments) that supports the growth of plants

Front 22

Texture

Back 22

refers to the proportions of different Soil Texture and Structure
particle sizes

• Sand (large size)
• Silt
• Clay (small size)

Front 23

Loam

Back 23

(a mixture of all three sizes) is best suited for plant life

Front 24

Structure

Back 24

Soil particles clumped together to give a soil its structure

Front 25

Controls of soil formation

Back 25

1. parent material
2. time (Important in all geologic processes • Amount of time to evolve varies for different soils)

Front 26

Parent Material

Back 26

• Residual soil – parent material of the soil (bedrock)
• Transported soil – parent material has been carried
from elsewhere and deposited

Front 27

soil texture and structure

Back 27

1. texture
2.structure
3.climate
4. plants and animal
5. slope (angle)

Front 28

competence

Back 28

maximum particle size

when velocity decreases, competence decreases and the size of the particle it can carry decreases

Front 29

alluvium

Back 29

- material that has been moved by a stream (NOT an ocean)

Front 30

Horizons

Back 30

• Horizons – zones or layers of soil

Front 31

O and A

Back 31

O – organic matter
A – organic and mineral

Front 32

topsoil

Back 32

(O + A = topsoil)

Front 33

Three very generic types of soil

Back 33

1. pedalfer
2. pedocal
3. laterite

Front 34

pedalfer

Back 34

Accumulation of iron oxides and Al-rich clays in the B-horizon
•
Best developed under forest vegetation

Front 35

pedocal

Back 35

• Accumulate calcium carbonate
• Associated with drier grasslands

Front 36

laterite

Back 36

• Hot, wet, tropical climates
• Intense chemical weathering

Front 37

Natural rates of erosion depend on

Back 37

• Soil characteristics
• Climate
• Slope
• Type of vegetation

Front 38

Weathering creates

Back 38

ore deposits

Front 39

Saturation of the material with water

Back 39

• Destroys particle cohesion

Front 40

mass wasting

Back 40

The downslope movement of rock, regolith, and soil under the direct influence of gravity

Front 41

important triggering factors of mass wasting

Back 41

• Oversteepening of slopes

vibrations from earthquakes

Front 42

Types of mass wasting processes

Back 42

defined by: material and movement of sediment

Front 43

types of movement

Back 43

1. Fall (free-fall of pieces)
2. Slide (material moves along a well- defined surface)
3. Flow(materialmovesasaviscous fluid)

Front 44

delta

Back 44

created by deposition in lakes or oceans

ex: nile or mississippi

Front 45

natural levee

Back 45

created by deposition; form parallel to the stream channel

Front 46

stream valley

Back 46

built through erosion

valley sides are shaped by: weathering, overland flow, mass wasting

Front 47

Narrow Valleys

Back 47

v-shaped

downcutting towards base level

Front 48

Wide Valleys

Back 48

flood plains, Meanders, Cutoffs, and Oxbow lakes

Front 49

cause of floods

Back 49

1. Weather
2. Human interference with the stream system

Front 50

Types of drainage patterns

Back 50

• Dendritic
• Radial
• Rectangular
• Trellis

Front 51

Groundwater

Back 51

Largest freshwater reservoir

Geological roles:
As Erosional agent:
• Sinkholes
• Caverns
• An equalizer of stream flow

Front 52

Zone of aeration

Back 52

• Unsaturated zone
• Pore spaces in the material are filled mainly with air

Front 53

Engineering efforts

Back 53

• Artificial levees
• Flood-control dams
• Channelization
• Nonstructural approach through sound floodplain management