*Unit 4 Flashcards
What are the three different plate boundaries?
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)
What are the layers of the earth (innermost to outermost)?
Inner Core, Outer Core, Lower Mantle, Asthenosphere, Lithosphere (where life is found)
How do earthquakes form?
Fault lines at transform boundaries “lock up” (build up stress and energy), and eventually release the energy in the form of an earthquake.
How are tsunamis generated along subduction zones, and what are their ecological consequences?
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.
Explain how subduction leads to volcanic activity.
One plate is pushed beneath the other, melts, then rises to the surface in the form of magma.
What factors affect soil formation.
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
What horizons make up the soil profile?
Bedrock, Substrata (contains the most parent material), Subsoil, Surface Horizon, Organic Matter (contains the most organic material)
What causes soil erosion?
Soil erodes due to water, wind, topography/gravity, and human factors (leads to water contamination)
How does farming influence soil erosion?
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.
Name the types of erosion into water and their solutions.
- 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
Describe two soil conservation practices that are designed to decrease soil erosion.
- No till farming, which disturbs the soil minimally, will keep the soil intact from water and wind erosion.
- Contour farming, where farming is gently sloped, helps to slow water runoff.
What is water holding capacity?
Water holding capacity is the idea that large particles like sand better allows water to pass through than small particles like clay.
What are soil triangles, and what are they used for?
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.
What is percolation? Infiltration?
Percolation is the movement of water into the ground and infiltration is the movement of ions or chemicals through percolation.
Describe the structure and composition of the world’s atmosphere.
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)