APES Unit 4: Soil Formation

Parent Material

the underlying rock material from which the inorganic of soil are derived

Weathering

the breakdown of rock as it is exposed to air, water, certain chemical compounds or biological agents such as lichens, plant roots, or burrowing organisms

Erosion

the physical removal of rock fragments form a ecosystem

What are some poor land practices the lead to lots of erosion?

deforestation, overgrazing, unmanaged construction/ mining, road construction

Five factor that determine the properties of soil:

parent material, climate, topography, organisms, and time

Soil degradation

the loss of some or all of a soil’s ability to support plant growth

Ecosystem services provided by soil

serves as a medium for plant growth, a habitat for other organisms, recycling system for organic wastes, also helps to filter and purify water

Soil

relatively thin, upper-most layer of Earth’s crust that supports plants, animals, and microbes

Humus

the most fully decomposed organic matter in the lowest section of the O horizon

Loam

an ideal agriculture soil that has an optimum combo of soil particle size; approx. 40% sand & silt & 20% clay

Soil formation

soil is a mixture of organic and inorganic matter. The breakdown of rock and primary minerals from the parent material provides the inorganic matter. The organic matter comes from organisms and their wastes. Parent material is weathered, transported, and deposited.

Horizon

A horizontal layer of soil defined by distinctive physical features such as texture and color

O horizon

the organic horizon at the surface of many soils, composed of organic detritus in various stages of decomposition

A horizon

frequently the top layer of soil, a zone of organic material and minerals that have been mixed together. Also known as top soil

E horizon

A zone of leaching, or eluviation, found in some acidic soils under the O horizon or, less often, the A horizon

B horizon

A soil horizon composed primarily of mineral material with very little organic matter.

C horizon

The least-weathered soil horizon, which always occurs beneath the B Horizon and is similar to the parent material

eluviation

the movement through soil of materials by the action of water

Leaching

removal of dissolved materials from soil by water percolating downward

Illuviation

the actual deposit in one layer of soil of materials that has been leached from another layer

Three properties of soil

physical, chemical, biological

Physical characteristics of soil

size, weight, texture, permeability, porosity

Chemical properties of soil are

cation exchange capacity(CEC), Base saturation

Biological properties of soil refer to

the activities of the many organisms living in soil

watershed

all the land in an area that drains into a particular stream, river, lake, or wetland

watersheds are characterized by:

area, length, slope, soil, vegetation

area

the area & length of a watershed combined paly a large role in the amount of water, the materials carried by the water, and the time required to move the water from the land to the water body at the outlet

slope

when land has a steep slope the water moves at much faster rate displacing soil and even large rocks. This can cause increases turbidity in water preventing photosynthesis.

soil type

sandy soils allow water to rapidly permeate, which means less water remains to runoff. However Clay and silt are less permeable leaving more water on the surface causing increased runoff & soil erosion

Global wind patterns

primarily result from the most intense solar radiation arriving at the equator, resulting in density difference and the coriolis effect

How much oxygen is in the atmosphere?

21%

How much nitrogen is in the atmosphere?

78%

How much argon, carbon dioxide, neon, and helium are in the atmosphere?

1%

What happens to density as distance increases from earth?

increases

Troposphere

where weather occurs, the first layer, densest, temperature increases with altitude

Stratosphere

ozone layer absorbs UV, important to the evolution of life on Earth & the continued health & survival of life on Earth

What are the layers in order from top to bottom?

exosphere, thermosphere, mesosphere, stratosphere, troposphere

Evidence for the tectonic plate theory:

identical rock on both sides of Atlantic ocean, shape of continents fits together, fossil of same time on different continent

Where do hotspots occur?

the mantle and earth’s outer core are said to be the cause of the radioactive decay that releases heat. The heat causes plumes of hot magma to well upward from the mantle. These plumes are hotspots.

3 plate boundaries:

divergent, convergent, and transform

Five factors affecting soil:

parent material, climate, topography, organisms, and time

Soil horizons in order:

O horizon, A horizon, E horizon, B horizon, and C horizon

Soil permeability

a measure of the ease with which fluids will flow through a porous rock, sediment, or soil

Porosity

the ratio of the volume of openings to the total volume of material. The more tightly packed the grains are; the lower the porosity.

Cation exchange capacity:

the ability of a particular soil to absorb and release cations

Base saturation:

The proportion of ions, expressed as a percentage.

Three groups of organisms account for most of the biological activity in soil:

bacteria, fungi, and protozoans

What are the Hadley cells?

atmospheric convections currents that operate between the equator and 30 N and 30 S.

What occurs during the Hadley cells?

Solar energy warms humid air in the tropics, the warm air rises and eventually cools below its saturation point, the water vapor it contains condenses into clouds and precipitation, the air, which now contains little moisture, sinks to earth’s surface at approximately 30 N and 30 S, as the air descends, it is warmed by adiabatic heating, this descent of hot, dry air causes desert environments to develop at those latitudes.

Coriolis effect:

The deflection of an object’s path due to the rotation of Earth

which way does the Coriolis effect turn in the Northern Hemisphere?

to the right

WHat directions does the coriolis effect turn into he southern hemisphere?

to the left

what is Earth’s main source of energy, and what two things for it depend on?

incoming solar radiation, depends on season and latitude

What factor determines the intensity of the suns rays?

the angle of the rays hitting Earth’s surface

Where on Earth is the highest solar radiation received per unit area?

At the equator

Why do high latitudes receive less intense solar radiation than the equator?

the sun’s rays hit a steeper angle, spreading the same amount of solar energy over a large surface area

Albedo

the percentage of incoming sunlight reflected from a surface

What happens during the December solstice?

northern hemisphere tilted away from sun, and has the shortest days

What happens during June solstice?

Northern hemisphere titled toward sun, has longest days

what is an equinox?

12 hours of light and 12 hours of dark

Rain shadow

A region with dry conditions found on the leeward side of mountain range as a result of humid winds from the ocean causing precipitation on the windward side

weather and climate aren’t just affected by the sun’s energy but by geologic & geographic factors like:

mountains and ocean temperatures

windward side:

the side facing the ocean and currents

leeward side:

the side has the rain shadow and is dry

atmospheric convention currents

global patterns moves clockwise in the Northern hemisphere and counterclockwise in the southern hemisphere

Gyre

a large scale pattern of water circulation that moves clockwise in the Northern hemisphere and counterclockwise in the southern hemisphere

Carbon sequestration

the capture and long-term storage of carbon dioxide form the atmosphere

El Nino-southern oscillation:

a reversal of wind and water currents in the south pacific