Unit 1: Earth Systems and Resources APES

When did the Earth form?

4.6 Billion Years Ago

How did the Earth form?

Huge clouds of gas debris collided with heavier elements produced by supernovae at extremely high tempratures

What formed as the earth cooled?

A solid crust

Four systems in the structure of the Earth

Lithosphere, hydrosphere, biosphere, atmosphere

The lithosphere

A brittle, rigid, and strong layer made up of the uppermost part of the mantle and the crust.

Divergent Boundaries

Two plates move away from each other. Magma from crust rises and cools. Can cause underwater mountains or valleys.

Convergent Boundaries (O+C)

Older oceanic plate subduct under less dense one, volcanic islands and earthquakes can happen.

Convergent Boundaries (O+O)

Denser oceanic plate subduct under less dense one, deep ocean trenches and earthquakes form

Convergent Boundaries (C+C)

Plates collide, crust crumples and folds. Can form large mountain ranges

Transform Boundaries

Plates slide past each other. Can form fault lines, shallow earthquakes, linear valleys.

Why do tectonic plates move?

The convection currents due to the temperature differences and plastic like nature of the mantle.

The Core (Inner)

Innermost portion of the earth. Primary composed of nickel and iron (solid). Very high density.

The Core (Outer)

Innermost portion of the earth. Primary composed of molten nickel and iron (liquid). Very high density.

The Mantle

Makes up majority of mass of Earth. Composed of magnesium, aluminum, and silicon-oxide compounds. Solid except for plastic like upper region.

The Crust

Outermost layer of earth.

Theory of Plate Tectonics

Lithosphere is made up of 7 major plates and several smaller ones.

Volcanoes

Typically occur at convergent plate boundaries. Due to the extreme heat of earth, large amounts of magma move up and can produce active volcanoes.

Effects of volcanic activity on the environment

Volcanic activity can destroy habitats and pollute air and water, but it also creates fertile soil, new land, and geothermal energy, supporting long-term environmental recovery.

Earthquakes

Caused by transform boundaries.

Ring of Fire

Area where majority of earthquakes occur in the pacific ocean.

Fracking

Injects high-pressure mixture of water, sand, and chemicals to crack the rock and release trapped gas or oil. Can induce earthquakes

Earth's Tilt

23.5 degrees

Equator

Receives the most direct sunlight

Poles

Only receive sunlight when they are pointed towards the sun. (Specific times of the year)

Arctic zone

Lowest light, covered in ice or snow most of the year.

Temperate zone

Located between arctic and tropic zones, experience the most distinct changes, large variation

Tropic zone

Located at equator, high light intensity, mostly covered in oceans, resulting in frequent rainfall.

Why do seasons occur at different times?

Due to the tilt and unequal heating, the hemispheres experience seasons at different points in the Earth's orbit.

Main components of Earth's system

Matter and Energy

The Big Bang

Occurred 15 billion years ago and created all the matter (atoms made of protons, neutrons, and electrons)

Earth is in a closed system

Matter cannot be created nor destroyed, rather it changes forms

Sources of Energy

Radioactive decay at the core of Earth and the Sun.

5 Layers of Atmosphere

Troposphere, stratosphere, mesosphere, thermosphere, exosphere

Composition of atmosphere

78.1% Nitrogen, 20.9% oxygen, 0.9% argon, 0.1% carbon dioxide, methane, water vapor, helium, ozone.

Role of nitrogen in living organisms

Essential for making up proteins

Role of oxygen in living organisms

Essential for human respiration

Troposphere

Area of atmosphere that we exist in. Can be 7 to 18 km thick.. Temp. decreases as distance from earth increases. Gasses make up 75% of the atmosphere --> High density and pressure.

Turbulent air in troposphere

Responsible for weather we experience

Tropopause

Highest level of troposphere. Coldest.

Stratosphere

Above troposphere. Contains about 24% of gasses in total atmosphere. Typically where airplanes exist. Temp increases as altitude increases because it directly absorbs solar radiation and ozone layer.

Mesosphere

Low concentration of gas. Low pressure. Largest range of temp. that decrease as altitude increases. Meteors burn up here.

Thermosphere

Temp. increases with an increase in altitude. Few gases and low pressure.

Exosphere

Highest layer of atmosphere. Only hydrogen and helium gas here. Extremely low pressure. Temp decreases as altitude increases.

Northern lights in thermosphere

Energy from sun causes gas atoms to form ions and plasma

Temp. Inversion layers

Stratosphere, thermosphere, possibly troposphere due to pollution.

Weather

The temperature, amount of rainfall, and humidity at a certain place and time.

Convection

As the sun heats gases in the atmosphere, denser colder air sinks and warmer less dense air rises. Creates wind.

Climate

The average weather patterns of a region over many years.

What is climate determined by?

The heating and cooling of the Earth's surface which occur due to energy exchanges of earth's atmosphere and oceans.

Temperature gradient

Causes warm air and water at the equator to travel to the poles and cool air and water at the poles to travel to the equator.

If Earth did not rotate...

The poles would be one large area of high pressure and the equator would be one large area of low pressure

Why does the movement of air not follow direct paths?

Because of earth's rotation

Coriolis Effect

Area around equator ravels faster than that of pole so air moving north is deflected east and air moving south is deflected west. Due to Earth's rotation around the axis

Convection Cells

Caused by coriolis effect. Six large ones, three in each hemisphere, that differ in the way air circulates.

Hadley Cells

Form near equator as warm air rises vertically, moves towards the poles, cools down and sinks back to the surface.

Ferrel Cells

Cold air sinks and moves toward poles and eastward before warming and rising again.

Polar Cells

Diverging of rising warm air that sinks over the poles.

Jet Streams

Where cold air meets warm air at boundaries between cells. Position, speed, and direction changes.

El Nino-Southern Oscillation, ENSO

Changing temperatures of the pacific ocean that impact weather patterns globally.

Water on Earth

97% Saltwater, 3% Freshwater

Composition of 3% Freshwater

2.2% Ice caps and glaciers, 0.8% useable freshwater

Water

Finite, renewable, moves through hydrologic cycle

Processes that add water to the atmosphere

Evaporation, transpiration, evapotranspiration, sublimation

Sustainable water use

Rate of consumption has to be less than or equal to the rate of recycling

Largest consumer of water

Agriculture (irrigation)

Water's unique properties

Polar, forms hydrogen bonds. High heat capacity, universal solvent, solid water has a lower density than liquid --> ice floats in water.

Hydrologic Cycle

Precipitation, runoff, evaporation.

Surface Water

Exists above ground on Earth (e.g. streams, rivers, ponds)

Runoff

Water that flows over land and hasn't been absorbed into the ground

Watershed

All of the land that supplies water to a river. Can have cascading effects if part is polluted.

Mississippi River Watershed

41% of US land

Aquifer

Underground layer of water

Ogallala Aquifer

Largest aquifer in North America.

Groundwater

Freshwater underground. Needs to be space between particles for water to exist. The deeper you go, the denser materials get, making less room for water.

How does groundwater exist?

Gravity pulls water towards the center of earth and bedrock underground allows water to accumulate. Comes from rain or snowmelt, surface water, septic tanks, irrigation.

Reservoirs

A large natural or artificial lake used as a source of water supply. Important to communities with less access to lakes and rivers. Provides drinking water, generate electricity, prevent communities from dangerous floods, and provide space for recreational activities.

Porosity

Measure of space between soil particles that can hold water and oxygen.

Permeability

How easily water can get into soil --> depends on size and shape of pores.

Recharge zones

Areas where water infiltrates the ground rather than becoming runoff.

Good recharge areas

Wetlands and flat vegetated areas

Least sustainable source of freshwater

Deep ground water.

What is crucial to maintaining the sustainability of aquifers?

Recharge zones

Salinization

High salt concentrations in water; result of extracting groundwater at a high rate.

Dams

Used to collect water in reservoirs.

Negatives of dams and reservoirs

Habitat destruction, increased salinization

Turning ocean water into freshwater

Desalinization, reverse osmosis, distillation

Sector responsible for the greatest consumption of water

Agricultural

Water insecurity

1.1 billion people lack access to clean water, and 2.7 billion have trouble finding fresh water for at least one month of the year.

Water Stress Causes

High populations, low precipitation.

The rock cycle

The process in which soil forms.

3 Types of Rocks

Igneous, sedimentary, metamorphic

8 Processes that change rocks into different types

Weathering, erosion, transportation, deposition, compaction, cementation, melting, metamorphism

Igneous Rock

Formed when magma cools and crystalizes below the surface or lava cools and crystallizes on the surface.

Sedimentary Rock

Formed when sediments settle into layers and are compacted and cemented.

Lithification

Layers being compacted and cemented

Metamorphic rock

Formed when high pressure and temperature changes the chemical composition of a rock.

Healthy soil composition

45% minerals, 25% water, 25% air, 5% organic matter

Soil

Composed of minerals, decomposing plant and animal matter, and open space filled with air and water. NON RENEWABLE

Weathering of Rock

Physical changes due to wind and water, chemical changes due to reactions with other substances, changes caused by activity of living organisms

Clay

Smallest particle size, small pores, retain water better