Chapter 11

Crystals

Crystals are the special shapes of minerals found in rocks made from molten rock (magma) that cooled slowly. Each type of mineral has a special crystal shape

Gemstones

Gemstones (or gems) are minerals that are valuable because of their exceptional beauty, colour, and rarity. Their main physical properties are colour, lustre (shininess), how light passes through them, and hardness. Gemstones are often made into jewellery. Many gemstones have important uses in manufacturing and electronics.

Igneous rocks

Igneous rock is the class of rock that forms from molten rock that has cooled and hardened. Rock that forms when magma cools slowly often contains large crystals.

Keeping it Warm, Keeping it Cool

Ocean currents flow in a circular pattern — clockwise in the northern hemisphere, where Canada is found, and counterclockwise in the southern hemisphere, south of the equator. There are three categories of ocean currents Ocean currents influence life in the oceans. The ocean is layered: warmer on top, cold at the bottom. Ocean organisms are sensitive to changes in temperature. A change in temperature of even a few degrees may be enough to cause these organisms to change their location. Other organisms that depend on them for food must also move or die of starvation.

Sedimentary Rocks

Sedimentary rock is the class of rock that forms from small pieces of rock, shells, or other materials that pile up in layers. The layers of rock at the bottom harden, forming sedimentary rock, like snow at the bottom of several layers turning to ice. Just as there are many different kinds of minerals that can pile up, there are many different kinds of sedimentary rock.

Weather and the Water Cycle

Since Earth is roughly a sphere the Sun's radiant energy does not fall evenly on Earth's land and seas. The sun shines more directly down in the land and ocean at and near the equator, hating them more strongly. In Canada the sun's rays fall less directly than at the equator. The same amount of heat is spread over a larger area o Earth's surface. The differences in temperature between regions near the equator and northern and southern regions set in motion a continuous movement of air across Earth.

Heat Transfer

The energy from the Sun that reaches Earth contributes to changes in Earth's weather systems and affects the weather in your local area.

Exosphere

The Exosphere from 690 to 10,000 km

Minerals

Minerals are naturally occurring solid pure substances. The first step in identifying a rock is to look at the minerals it contains. There are over 4000 known minerals.

The Rock Cycle

The rock cycle is the repeating pattern in which one family of rock changes into a different family. The rock cycle occurs because of the hear produced, stored, and released inside Earth. Old rock is continuously being pushed into the mantle, where it melts. Hot magma reaches the crust, cools, and forms new rock. Rocks change constantly. Pressure from the weight of layers of rock pushing down may change one form of rock into another. Water, wind, chemicals, and even living things, lead to weathering, or wearing away, of rock.

Earthquakes

The shifting of the plates produces shaking and sliding in the crust as an earthquake takes place.

Stratosphere

The stratosphere- from 20-50 km

Metamorphic Rocks

etamorphic rock is formed from igneous or sedimentary rocks that have been changed from their original form by heat (from Earth) or by the pressure of the rocks above them. As there are many different minerals that make up igneous rocks and sedimentary rocks, there are also many different types of metamorphic rocks. Two rocks can contain exactly the same set of minerals but look very different because they formed in different ways.

Plates

Earth's crust sits on large, thick sections of rock called plates. Because the mantle is made of hot, molten rock, these large rock plates ca move apart or move together.

Heat and Ocean Currents

An ocean current is a pattern of movement of the water in a large region of the ocean. Ocean currents contribute to the movement of thermal energy from the warm regions of Earth near the equator to the colder regions in the Arctic and Antarctic. In effect, these convection currents partially balance the extremes of temperature on Earth's surface. An ocean current is like a river of warm or cold water moving in a more or less circular pattern. This pattern influences the climate. The climate is the long-term weather conditions over large areas of Earth. Ocean currents flow in convection patterns that depend on wind, the minerals dissolved in the water, the shape of the ocean floor in different locations, heat from the Sun, the pull of the Moon's gravity, and even Earth's rotation.

Outer core

Earth's molten outer core is right above the inner core. The temperatures are so high here that the rock is completely liquid. Even though the rock is molten. This layer us also very thick about 2,200 km.

Lava

Deep under the oceans, hot magma may squeeze upwards where rock plates are moving apart. The hot magma is released onto the ocean floor as lava. Lava contains small crystals.

How are diamonds formed?

Diamonds are a form of carbon. Diamonds were first formed underground more than 2.5 billion years ago. They were crystallized in the mantle below Earth's crust at great depths, usually more than 150 km down. Rocks in Earth's upper mantle were carried deeper into the mantle where they melted. These rocks contained carbon, and on melting released carbon particles. The carbon particles formed crystals under the very high pressure from the molten rock above. Under the right conditions of heat and pressure, diamond crystals formed. The diamonds were carried toward the surface by volcanic eruptions of flowing magma in the mantle. Below the volcano, carrot-shaped deposits of rock formed. These deposits contain diamonds, volcanic rock, and fragments of the mantle.

Atmosphere

Earth's atmosphere is a blanket of gas that surrounds earth. The atmosphere includes the air humans need to live. It also includes a mixture of dirt, dust. and other substances such as pollution.

Crust

Earth's outer layer is the crust. All the features we see around us-mountains, valleys, plains, hills,-- are part of the crust. The crust is the thinnest on the bottom of the ocean. It is only about 6 km thick.

Learning about Layers of Air

Humans live in the bottom layer of the atmosphere. The atmosphere is divided into five main layers according to the changes in temperature as you go higher above Earth's surface.

The Troposphere

Humans live in the lowest level of Earth's atmosphere — the troposphere. Almost all human activity, including air travel, goes on in this layer.

Sun

Our Sun is the source of a huge amount of energy. Only a small fraction of it reaches our planet. Even so, the amount of energy reaching Earth's surface every day is more than 6000 times the amount of energy used by all humans on Earth in a day.

Rocks

Rocks are naturally formed solid material made up of one or more minerals.

Thermosphere

The Thermosphere from 85 to 690 km

Heat Flow in the water cycle

The energy of the Sun is directly responsible for three very important natural systems that affect life on Earth — the water cycle, weather patterns, and ocean currents. Think about the water cycle. You have seen that adding heat to water by boiling causes the water to change from a liquid to a gas. But it is not necessary to boil water to cause this change of state. Adding a smaller amount of heat has the same result; it just happens more slowly. Water in a puddle slowly seems to disappear, even on a cloudy day. In fact, it evaporates — turning into invisible water vapour. On the other hand, when hot steam touches a cool surface, it condenses, changing from water vapour to liquid water. These observations indicate a cycle, a continuous movement of materials in nature that repeats. The mist on the bathroom mirror is a home version of part of Earth's water cycle — the movement in nature of water from the surface of Earth to the atmosphere and back.Water in the atmosphere is not always invisible. When the temperature high above Earth starts to decrease, water droplets join together. Slowly, the smaller droplets become larger droplets, forming a cloud that we can see. As the water droplets grow even larger, they also become heavier and will begin to fall as rain, also called precipitation. Puddles of water evaporate due to heat. As the temperature drops, water droplets in clouds join together and fall as rain. You can see that heat plays a role in the two changes of state in the water cycle: • evaporation (liquid water on Earth absorbs heat and changes into water vapour) • condensation (invisible water vapour in the atmosphere cools down and changes back into drops of water that fall as rain).

Spinning systems

The moving atmosphere and oceans circulate continuously. The results are wind and storms in the troposphere and currents in the oceans. Strong winds can be very destructive and may produce hurricanes and tornadoes. A hurricane is a strong, spinning weather system over the ocean that has continuous winds exceeding 119 km/h. Hurricanes form and grow stronger as they pick up heat from warm tropical ocean water. Tornadoes are strong, spinning columns of air in contact with the ground. They are unpredictable, usually local, and last only a short time.

Mesosphere

The mesosphere from 50 to 85 km

Volcano

The movement allows magma, ash, and gases to shoot upward the crust causing cracks, producing rumbling in the ground and a lightning of the night sky as a volcano erupts.

Water Cycle

The movement in nature of water from the surface of Earth to the atmosphere and back.

Wind

The movement of air in the troposphere is called wind.

New Crust forms all the time

The three types of heat transfer (conduction, convection, and radiation) all play their part in the continuing story of the changes on and beneath Earth's surface. Conduction occurs in the solid inner core. Heat is transferred to the neighbouring molten outer core. This molten (melted) rock below Earth's surface is called magma. The magma in the outer core and the deeper part of the mantle is hotter than the magma in the upper part of the mantle near Earth's crust. This difference in temperature creates convection currents in the molten rock in the mantle. Hot, molten rock rises toward the top of the mantle and moves to the side. Heat is also transferred during this sideways movement by conduction and radiation.

The five layers of the atmosphere

The troposphere- form 0 to 20 km

Inner Core

This layer is solid even though it is really hot. The weight of the other layers has pressed the inner core into an extremely hard ball. There are still another 1250 km to the centre of Earth. But the inner core is so hard.

Inner core

This layer is solid even though it is very hot. The weight of ht either layers has pressed the inner core into an extremely hard ball. there are still another 1250 km to the centre of Earth but the inner core is so hard.

Magma

This molten (melted) rock below Earth's surface is called magma.

Weather

Weather refers to the conditions of Earth's atmosphere at a particular time and in a particular place. The study of weather and weather patterns is called meteorology.

Wind more complex definition

When air in one region is warmer than the surrounding air, it becomes less dense and begins to rise, drawing more air in underneath. During the day, land heats up more than water. The air above the land near large lakes or an ocean heats up and rises. Cooler air form above the water rushes in creating a cool sea breeze. At night, when the land cools down more quickly than the water, the opposite is true.