In the first chapter, we review planet Earth's structure and materials from which it is made, as well as those used by humans as resources for our needs and economic gain.
According to the College Board, about 10 to 15 percent of the test is based on this chapter.
If you don't know anything about the topic, you should consult your textbook for more information.
The College Board calls this section "Earth Systems and Resources".
The chapter begins with a brief Welcome to Planet Earth, which provides information on the planet's age and location in the solar system.
The materials and structure of the four physical spheres that make up our planet and regulate life on Earth are related to the remaining topics.
We discuss the importance of each sphere to humans.
The upper shell of the Solid Earth is the part that interacts with the other spheres.
Topics: the greenhouse effect, climate, and weather events.
Topics: soil's makeup, soil development, and soil issues.
We'll go through everything you need to know about the systems for test day after we review the discussion of the four spheres.
The resources provided by the four physical spheres support the fifth of Earth's spheres.
The living organisms that live on the planet draw on the physical resources of the other four spheres.
In the next chapter, we'll discuss the biosphere.
Earth's history is the first thing you should know.
The planet is thought to be between 4.5 and 4.8 billion years old.
The following geologic time scale will help you understand the amount of time that has passed since Earth was formed.
You don't have to memorize all of the eons, eras, periods, and epochs, but you should be familiar with the major ones.
There are some important things learned from this table.
We are in the middle of the past.
The two most recent geologic periods are the Quaternary and Tertiary.
Dinosaurs lived in the past.
Most of the geologic time scale is represented by the Precambrian eons.
The Anthropocene will recognize humankind's effects on the planet's physical resources, climate, and life forms.
Many people think that we have entered the new, post-Holocene era.
The third planet from the Sun in our solar system is known as Earth.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, and Neptune can be seen from the Sun.
Each planet has its own ellipse around the Sun.
It takes Earth about a year to complete its circle of the Sun.
Planet Earth has three zones of rocks that are either solid or liquid.
The core is the innermost zone.
A solid inner core and molten outer core make up the core.
The inner core is made of nickel and iron and is solid due to the tremendous pressure from overlying matter.
The outer core is mostly iron, mixed with nickel and lighter elements, and is semi-solid due to lower pressure.
The mantle is made mostly of rock.
The asthenosphere lies near the top of the mantle.
The Earth's outer shell is made of a thin, rigid layer of rock.
The upper mantle above the asthenosphere and the solid surface of the Earth are part of the lithoosphere.
Think of it as a cracker atop a thick layer of hot pudding.
The chemical and physical properties of Earth's layers are shown in the diagrams.
Scientists theorize that the continents formed a supercontinent called Pangaea during the Paleozoic Era.
Pangaea began to break apart 200 million years ago.
The word pan meant whole in ancient Greek, while the word gaia meant Earth.
It is believed that the Earth's crust is made up of several large pieces of lithoosphere--called tectonic plates--that move slowly over the mantle of the Earth.
There are at least a dozen plates that move independently.
The majority of the land is above six giant plates, while the rest is under the ocean and the continents.
The Nazca plate, which lies off the west coast of South America, is one of the plates that only contains ocean floor.
The United States is located in the North American plate, which extends out to the mid-Atlantic ridge.
The boundaries of the plate are almost identical to those of Turkey.
The largest plate is the Pacific plate, which includes Mexico's Baja Peninsula and southwestern California.
The major plates of Earth are shown on the map.
The places where two plates abut each other are called plate boundaries and are where events like sea floor spreading and earthquakes occur.
There are three different types of plate boundary interactions.
Two plates are pushed into each other.
One of the plates is pushed into the mantle.
Two plates are moving away from each other.
There is a gap between the plates that may be filled with rising magma.
New crust forms when this magma cools.
Two plates slide against each other in opposite directions when you warm them up.
Simply transform boundaries are what these are called.
Depending on the location of the collision, it is either between two oceanic boundaries or between two continental boundaries.
Subduction is when a heavy ocean plate is pushed below the other plate and melted as it encounters the hot mantle.
Plates that form large mountain chains as they crunch into each other are the result of orogeny.
The Himalayas, which were created by a collision between the plate carrying India and the Asian plate, are examples.
The creation of volcanoes and earthquakes is a result of plate movement.
magma rises from Earth's interior and forms mountains.
Within the last 10,000 years, active and dormant volcanoes have not been known to erupt.
It is thought that extinct volcanoes will never erupt again.
The kind of tectonic event that produces active volcanoes are categorized.
Subduction zones can be between two plates or between two plates.
The subducting plate is recycled into new magma, which rises through the overlying plate to create volcanoes inland.
The valleys are usually between two plates.
A new ocean floor is formed by the filling of a gap between plates.
pillow lava is formed when thick magma rises from rift valleys and comes into contact with the cold ocean water.
The Great Rift Valley of eastern Africa is an example of a valley between continental plates.
Hot spots don't form at plate boundaries.
They are found in the middle of the plates, in places where columns of hot magma melt through the mantle and weaken the Earth's crust.
The Hawaiian islands form over a hot spot beneath the Pacific plate.
The basaltic eruptions over the hot spots are milder than the rhyolitic eruptions over the continental hot spots.
Shield volcanoes are tall with gentle slopes and have a broad base.
They form over hot spots and have eruptions with slow lava flow.
When water enters the vent, it can form a fluidized mixture of hot ash and rock.
The volcanoes have a broad base and are tall.
They are formed at subduction zones and are associated with violent eruptions.
Cinder volcanoes are small and steep.
They form when molten lava erupts and cools quickly in the air, turning into porous rocks that break as they hit Earth's surface.
Cinder volcanoes form near other types of volcanoes.
The domes are small and have steep slopes.
They are formed from lava that is too dense to travel far.
Earthquakes are caused by the release of stored energy from deep in the Earth due to sudden plate movements.
Earth's tectonic plates move at about the same pace as fingernails, but earthquakes are very sudden.
Two plates slide past each other at a transform boundary.
The epicenter of the earthquake is the location at which it begins within the Earth.
The seismograph was invented in 1935 and is used to measure the size of earthquakes.
The highest S-wave of an earthquake is measured on the Richter scale.
There is no maximum value, but observed values range from 0 to 9.5.
A shear wave is a body wave that shakes the ground up and down or side to side.
The nation of Haiti was struck by an earthquake in January of 2010.
The epicenter was in the boundary region between the Caribbean plate and the North American plate.
There were 222,570 people killed, 300,000 injured, 1.3 million displaced, 97,289 houses destroyed, and 188,383 damaged in the earthquake in Haiti.
At least 4 people were killed by a local wave in the Petit Paradis area.
Waves caused by an earthquake or volcanic eruption can be very destructive and can be very large.
The eastern coast of Japan was hit by an earthquake in March of 2011.
The wave was 33 feet high.
Many buildings, roads, and railways were destroyed, major fires occurred, villages were washed away, and at least three nuclear power plants were 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217
Our buildings, the soil, and the rocks used in industry are all around us.
Other rocks is the answer.
The oldest rocks on the planet are 3.8 billion years old.
Rocks are recycled.
The rock cycle describes these transformations.
Three basic types of rocks are created when time, pressure, and the Earth's heat interact.
When rock is melted into a liquid, it resolidifies when cooled.
The molten rock (magma) comes to the surface of the Earth, and when it emerges it is called lava.
An example of a rock is basalt.
As the remains of plants and animals build up, the rock is formed.
A stream bed or ocean floor contains dissolved minerals that form under water.
As more material is deposited, they are compressed.
Limestone is an example of a rock.
Pressure and heat can cause physical and/or chemical changes in existing rock.
The high temperatures found in the Earth's mantle can cause this to happen.
Slate is a example of a metamorphic rock.
The diagram shows the rock cycle.
The atmosphere is a layer of gases held close to Earth by the force of gravity.
The inner four layers of the atmosphere reach an altitude of just over 12% of Earth's radius.
The troposphere is a layer of gases that extends from the surface of Earth to the poles and the equator.
The weather that we experience takes place in the troposphere.
99% of the atmosphere's water vapor and clouds can be found in the layer.
The troposphere is mixed from bottom to top with the exception of periodic temperature changes.
The troposphere gets colder with altitude, decreasing by datememe for every kilometer of altitude or by datememe for every thousand feet.
75% of Earth's atmosphere is by mass because of the density of the troposphere.
You've probably heard about the troposphere before, because of the greenhouse effect.
The air we breathe is made up of 22% oxygen and 22% nitrogen.
The "greenhouse" gases are included in the remaining 1%.
Water vapor, carbon dioxide, and methane are the three most important gases in the troposphere, and their effects on Earth are disproportionately significant.
Greenhouse gases in the troposphere absorb a lot of the solar radiation that is reflected back into space.
The warming effect of greenhouse gases was a good thing until after the Industrial Revolution.
We'll look at the greenhouse effect further in Chapter 9.
The tropopause is a layer that protects the troposphere from the next layer up.
The buffer zone is where the jet streams travel, air currents are important drivers of weather patterns and important factors in planning airline routes.
The stratosphere is on top of the tropopause and spans about 50 km above Earth's surface.
Gases in the stratosphere are not well mixed and temperatures increase with distance from the Earth.
There is a thin band of ozone in the lower half of the layer.
The ozone protects the troposphere and Earth's surface from the high-energy radiation of the Sun.
The troposphere is a dense and dry place with a lot of water.
Commercial jets can fly in the lower part of this layer.
The mesosphere and thermoosphere are above the ground.
The area above Earth's surface where meteorites burn up is called the mesosphere.
The thermoosphere extends from 80 to 500 km above the Earth.
The northern lights and southern lights take place because of the thin gases in this layer.
The upper limit of the exosphere, which is more than 6000 miles above the Earth, is not certain.
The concentration of gases is very small here.
Satellites are made in the exosphere and upper thermoosphere.
The upper mesosphere, the thermoosphere, and the lower exosphere are all covered in the ionosphere.
Most of the charged particles from the Sun are absorbed by the ionosphere.
Long-distance radio communication is possible because the ionosphere reflects radio waves.
You will need to know how the climates on Earth are created by the atmosphere.
Earth's atmosphere has physical features that change from day to day as well as patterns that are consistent over time.
The day-to-day properties such as wind speed and direction, temperature, amount of sunlight, pressure, and humidity are referred to as weather.
Climate is the pattern that is constant over many years.
Average temperature and precipitation amounts are the most important factors in describing the climate.
Scientists who study weather and climate are called meteorologyologists.
The weather and climate of any given area is the result of the Sun warming Earth and the gases above it, as well as Earth's rotation.
Solar heating, the rotation of Earth, and the physical properties of air, water, and land all contribute to the motion of air around the globe.
There are three reasons why Earth is not evenly heated.
More of the Sun's rays hit the Earth at the equator than at the poles.
The Sun's rays strike the Earth more directly at the equator.
The areas that are pointed toward the Sun receive more intense light than those that are pointed away.
The seasons are caused by this.
The rotation time at the equator is the same as at the poles, but the equator's surface is moving faster.
An object or air mass that is closer to the equator will maintain its eastward movement as it moves away from the equator.
The winds that move north from the equator near the surface are diverted to the right or east, while the winds that move south from the equator are diverted to the left or east.
The winds blowing toward the equator will be diverted to the west because they are moving eastward more slowly than in the lower latitudes.
In the Northern Hemisphere it will be to the right, and in the Southern Hemisphere it will be to the left.
This pattern is called the Coriolis effect.
The prevailing winds are belts of air that distribute heat and humidity around the globe.
Radiation heating transfers heat to the atmosphere.
The warmed gases expand, become less dense, and rise, creating vertical air flow called convection currents.
The warm currents can hold a lot of water.
Cool air flows along Earth's surface to fill the area left by the warm air.
There are ways in which surface winds are created.
As warm moist air rises into the cooler atmosphere, it cools to the dew point, the temperature at which water vapor condenses into liquid water.
The condensation creates clouds.
If condensation continues and the water drops get bigger, they can no longer be held up by Earth's atmosphere and they fall as precipitation, which can be frozen or liquid.
The dry air is denser than the surrounding air.
This air mass sinks to Earth's surface, where it can gather more water, thus starting the rotation of the cells.
On a local level, this phenomenon accounts for land and sea breezes.
On a global scale, these cells are called Hadley cells.
The warm, moist air rises into the atmosphere when a large Hadley cell starts its cycle over the equator.
One of the reasons for the abundant rainforests is the precipitation in that region.
The belts of deserts occur at the latitudes north and south of the equator after the cool, dry air descends.