*Unit 4

Question 1

What are the three different plate boundaries?

Answer 1

Convergent Boundaries: Two plates push towards each other causing the subduction of one. These collisions typically cause volcanoes, earthquakes, and trenches to occur. (ex. Mariana Trench, Himalayas, Andes)

Divergent Boundaries: Two plates push away from each other causing convection (the movement of magma into the area between the separated plates). This causes ridges and volcanoes to form. (ex. mid-Atlantic ridge)

Transform/Strike-slip Boundaries: Two plates slide past each other causing friction between. This tends to cause frequent earthquakes (doesn’t normally cause volcanoes). (ex. San Andreas Fault Zone)

Question 2

What are the layers of the earth (innermost to outermost)?

Answer 2

Inner Core, Outer Core, Lower Mantle, Asthenosphere, Lithosphere (where life is found)

Question 3

How do earthquakes form?

Answer 3

Fault lines at transform boundaries “lock up” (build up stress and energy), and eventually release the energy in the form of an earthquake.

Question 4

How are tsunamis generated along subduction zones, and what are their ecological consequences?

Answer 4

Breaks in fault lines cause upward waves to form from the displacement of water. These gain power as they near shorelines and are incredibly powerful. They can destroy habitats, drown species, uproot trees, and contaminate water with salt water and debris.

Question 5

Explain how subduction leads to volcanic activity.

Answer 5

One plate is pushed beneath the other, melts, then rises to the surface in the form of magma.

Question 6

What factors affect soil formation.

Answer 6

Factors:

• Type of parent material: rocks are broken down by wind and rain; soil tends to retain the basic chemistry of these rocks.
• Climate: average temperature and moisture change of weathering and leaching (nutrients in water), wind redistribution as well.
• Topography: slope of the land may affect erosion.
• Biological factors: plants, animals, microorganisms
• Time: soil formation is a continuous process

Question 7

What horizons make up the soil profile?

Answer 7

Bedrock, Substrata (contains the most parent material), Subsoil, Surface Horizon, Organic Matter (contains the most organic material)

Question 8

What causes soil erosion?

Answer 8

Soil erodes due to water, wind, topography/gravity, and human factors (leads to water contamination)

Question 9

How does farming influence soil erosion?

Answer 9

Deforestation - The lack of roots holding down soil/Plants are often replaced with others that worsen erosion

Overgrazing - Pastureland can lead to cattle overeating and the top layer of soil can erode with wind and rain

Pesticides and Fertilizers - These change the chemistry of soil and kill the microorganisms in it

Tillage Practices - Turning and breaking up soil keeps the top layer from accumulating organic material and roots.

Question 10

Name the types of erosion into water and their solutions.

Answer 10

• Sheet Erosion (surface layer is removed by water) > Maintain plant cover
• Rill Erosion (small channels of water flow) > Strip cropping or contour plowing
• Gully Erosion (wider cuts from expanded rill erosion) > Divert water away from rills and gullies

Question 11

Describe two soil conservation practices that are designed to decrease soil erosion.

Answer 11

1. No till farming, which disturbs the soil minimally, will keep the soil intact from water and wind erosion.
2. Contour farming, where farming is gently sloped, helps to slow water runoff.

Question 12

What is water holding capacity?

Answer 12

Water holding capacity is the idea that large particles like sand better allows water to pass through than small particles like clay.

Question 13

What are soil triangles, and what are they used for?

Answer 13

Soil triangles are used to measure soil composition and to determine the types of soil in an ecosystem by using percentages of sand, silt, and clay.

Question 14

What is percolation? Infiltration?

Answer 14

Percolation is the movement of water into the ground and infiltration is the movement of ions or chemicals through percolation.

Question 15

Describe the structure and composition of the world’s atmosphere.

Answer 15

The atmosphere is made up of a mix of gases (Nitrogen, Oxygen, Trace Gases others) and organized into layers.

Topographic Layers:

• Troposphere (bottom most)
• Stratosphere
• Mesosphere
• Thermosphere
• Exosphere (upper most)

Question 16

What is the Coriolis Effect?

Answer 16

The Coriolis Effect is the phenomenon where heat and rotation of the earth deflects wind.

Question 17

What drives global winds?

Answer 17

The atmosphere is held by gravity, and as the earth rotates, air circulates. Heating and cooling changes the density of air due to convection patterns (hot air rises because it is less dense).

Question 18

What make up watersheds (aquatic elements)?

Answer 18

The highest points of watersheds are called divides. These are followed by tributaries - small rivers which lead into larger ones - and rivers. The delta is where the river meets the larger body of water, the groundwater/aquifer.

Question 19

What make up watersheds (terrestrial elements)?

Answer 19

The source zone is where rain is collected or ice caps melting into, causing rivers to form. Then comes the transition zone and floodplain zone (where the river spreads out).

Question 20

What causes rivers to flow?

Answer 20

Gravity causes rivers to move downward.

Question 21

How does human action affect watersheds?

Answer 21

Logging leaks pesticides in the ground into rivers, pollution from industrial sites can end up in rivers, and dams block the flow of sediment.

Question 22

What is insolation?

Answer 22

INcoming SOLar radiation (Solar Radiation/Area)

Question 23

When do each of the seasons begin?

Answer 23

Winter Solstice: December 21-22
Vernal Equinox (Spring): March 20-21
Summer Solstice: June 20-22
Autumnal Equinox: September 22-23

Question 24

How far is the earth tilted on its axis?

Answer 24

23.5˚

Question 25

What is the difference between when solar radiation hits land vs water?

Answer 25

Land - low specific heat + no mobility = quicker temperature increase

Water - high specific heat + high mobility = slower temperature increase

Question 26

Explain the effect of solar radiation on coastal regions.

Answer 26

Coastal regions have more stable climates due to the large bodies of water that surround them.

Question 27

Explain the effect of ocean currents on regional temperature.

Answer 27

Currents in large bodies of water can make the land adjacent to them cooler or warmer than expected.

Question 28

What is the Rainshadow Effect?

Answer 28

The Rainshadow Effect predicts the location of rainfall, vegetation, and dry/arid along the slopes of coastal mountains and on the leeward side of coastal mountains.

Question 29

Why is the windward side of a mountain wet and rainy and the leeward side dry/arid?

Answer 29

Rainshadow Effect. Ocean breezes blow off from the ocean to the mountain, bringing in a lot of moisture. When these windward side breezes hit the mountain, they are shunted upward, and as we know, air cools as it rises. As the water vapor in the air cools, it creates clouds and rain, causing the windward side of the mountain to have lots of vegetation. In contrast, Air crests at the top of a mountain, so when it comes back down on the leeward side, it expands and becomes warmer. This causes the leeward side of mountains to often be deserts.

Question 30

What are El Niño and La Niña?

Answer 30

El Niño/La Niña are phenomena associated with changing ocean surface temperatures in the Pacific Ocean. They can cause global changes to rainfall, wind, and ocean circulation patterns.

Question 31

What is ENSO?

Answer 31

ENSO stands for El Niño - Southern Oscillation (Refers to both El Niño and La Niña), and it’s a regular event that occurs at the beginning of December every 3-7 years. It is located in the southern hemisphere of the Pacific Ocean, between Australia and South America.

Question 32

What is the difference between neutral conditions and El Niño? La Niña?

Answer 32

In neutral conditions, there are easterly trade winds moving from South America to Australia, and upwelling that supports schools of fish along the coast. However, in El Niño, winds stall and become westerlies and upwelling becomes suppressed. The reduction in fish population impacts commercial fishing in South America. In La Niña, neutral conditions are enhanced (stronger trade winds, more moisture driven into the atmosphere, etc.).

Question 33

What are the ecological impacts of El Niño?

Answer 33

• Drought in Australia due to drier conditions reduces plant productivity
• Fires in Australia due to drier conditions damages native habitats
• Floods in coastal, tropical South America due to wetter conditions damage native habitats

Question 34

What are the terrestrial impacts of La Niña?

Answer 34

• Wetter conditions in Australia and Indonesia, which increases the risk for floods and landslides
• Cooler and drier conditions in South America
• Colder winter in Canada and Northern US

Question 35

What are the economic impacts of El Niño?

Answer 35

• Income lost by commercial fishing companies because of reduction in fish populations off the coast of South America
• Economic losses associated with ecological impacts that also impact human constructs (ex. loss of sales due to crops that did not grow in Australia as a result of the ENSO-related drought)