(10) Planet Blue

 THAILAND TSUNAMI 2004

Tsunamis

Tsunami

Hurricanes and Tornadoes

 Hurricanes are strong cyclones that originate in the oceans, near the tropics. They are accompanied by heavy rainfall and winds blowing at speeds of 75 mph.

Categories of Hurricane

Hurricanes are classified into five categories, based on their wind speeds and potential to cause damage.

• The World Meteorological Organization gives names to hurricanes.

• Hurricanes that form in the western Pacific Ocean are called typhoons.

• Hurricane season is the time when most Atlantic Ocean hurricanes occur.

• The eye is the calm and roughly circular center of a hurricane.

• Some tornadoes can have wind speeds of more than 300 mph.

• The word tornado comes from the Spanish word tronada, which means thunderstorm.

Hurricanes Wind velocity

Category One Winds 74–95 mph

Category Two Winds 96–110 mph

Category Three Winds 111–130 mph

Category Four Winds 131–155 mph

Category Five Winds greater than 155 mph

A tornado is a rotating violent wind that extends towards the ground from the clouds. Tornadoes are funnel-shaped with their narrow end towards the ground.

Tsunami

Tsunamis are tidal waves that occur on the surface of the ocean. They are caused by earthquakes and volcanic eruptions under the sea.

• Tsunamis are surface gravity waves.

• Tsunami waves can travel across the ocean at speeds of more than 500 mph.

• Japan is a nation with the most recorded tsunamis in the world.

• The 2004 Indian Ocean tsunami is the deadliest tsunami in recorded history.

• Tsunamis are most prevalent in the Pacific Ocean.

• 3.5 billion years ago, an asteroid collision created a giant tsunami that swept around Earth several times.

• When the ocean is deep, tsunamis can cross the entire ocean in a day or less.

• It is believed that a tsunami sounds like a freight train.

• Tsunamis can even travel up rivers and streams that lead to the ocean.

Megatsunami

A megatsunami is an informal term used to describe a very large tsunami wave.

Rising High

Once the tsunami wave reaches the coast, its top moves faster than the bottom, which causes the sea to rise dramatically

Oceans

Oceans were formed as a result of the redistribution of mantle materials within Earth, as they rose to the surface. Millions of years ago, as Earth warmed, lava, gases, and water vapor locked in Earth’s crust were released. These were carried to the surface by volcanic activity and formed the early atmosphere. Water vapor condensed into clouds bringing the first rain on Earth. Once the water cycle began, oceans starting forming.

The highest tides on Earth are found in the Bay of Fundy east of New Brunswick, Canada.

• The largest waterfall on Earth is actually underwater, found in the Denmark Strait.

• About 97% of all of Earth's water is saltwater found in oceans.

• The temperature of most ocean water is about 39° F.

• 90% of all volcanic activity occurs in the oceans.

• The pressure at the deepest point in the ocean is more than eight tons per square inch.

• The top ten feet of the ocean hold as much heat as the entire atmosphere.

Tides

Tides are the periodic rise and fall in the ocean’s surface caused by the gravitational attraction between Earth and the moon.

Oceanic Ridge

Oceanic ridges are mountains under the oceans formed by the movement of tectonic plates

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(9) Planet Blue

Studying Alaska's ice and snow to track climate change

Climate Change - Snow & Ice

Snow

Snow

Snow is a form of precipitation. Snow is formed when the water vapor in the clouds turn into tiny ice crystals. It is formed in the atmosphere at temperatures below freezing point.

Fact Scope

• Flurries are short-period snowfalls.

• Coarse, granular wet snow is also known as corn.

• Powder is freshly fallen, uncompacted snow.

• A snowstorm is a heavy storm of snow for a relatively long period.

• A snow squall is a very intense snowstorm for a brief period of time.

• Slush is snow which partially melts upon reaching the ground.

• Penitentes are tall blades of snow and spiked ice found at high altitudes.

• Freezing rain is rain that freezes on impact with a sufficiently cold surface.

Blizzard

A blizzard is a long-lasting snowstorm, where visibility is reduced to less than 3.2 feet.

Snowflake

Snowflakes are a collection of ice crystals.

Weather and Climate

Weather is the state or condition of the atmosphere of a place that exists over a short period of time. It is characterized by change in temperature, wind, atmospheric pressure and the rainfall of a place at any given time. Climate is the average weather of a place over a period of several years. Different places have different climates. The climate of a place can be affected by some major factors such as latitude, altitude, and distance from the sea.

Fact Scope

• Weather occurs mostly in the troposphere.

• A barograph is a device used to measure air pressure.

• An anemometer is a device used to measure wind speed.

• There are about 11,000 weather stations in the world.

• In 1648 Blaise Pascal discovered that atmospheric pressure decreases with height.

• Benjamin Franklin observed the link between volcanic eruption and weather.

• TIROS-1, the first successful weather satellite, was launched in 1960.

• Francis Beaufort and Robert Fitzroy are credited with the birth of weather forecasting as a science.

Meteorology

Meteorology is the study of weather and climatic conditions.

Factors Affecting Weather

The three key factors that determine weather conditions are air temperature, air pressure, and humidity.

Flood and Drought

A flood is the overflowing of water over areas that are normally dry. A flood generally occurs because of heavy rainfall, onshore waves, or rapid snow melting. Crops and people are greatly affected by floods.

A drought is a condition of no rainfall with extreme dry weather. It occurs for a long period, sometimes for months or years, wiping out all plant and animal life. Severe droughts generally occur in deserts and areas bordering deserts.

Fact Scope

In the last 2,000 years, the Yangtze River in China has flooded more than 1,000 times.

• In 1970 the Aswan High Dam was constructed to stop the annual floods of Nile River.

• A meteorological drought is drought caused by prolonged periods of less than average rainfall in a specific region.

• An agricultural drought is caused when there is insufficient moisture for crop production.

• A hydrological drought is caused when water reserves in the lakes and reservoirs fall below normal.

• The Great Leap Forward famine that occurred in 1958–61 in China is regarded as the largest famine of all time.

China's Sorrow

Hwang Ho or “Yellow River” is called “China's sorrow,” because it has caused more destruction than any other river in the world.

• In the last 2,000 years, the Yangtze River in China has flooded more than 1,000 times.

• In 1970 the Aswan High Dam was constructed to stop the annual floods of Nile River.

• A meteorological drought is drought caused by prolonged periods of less than average rainfall in a specific region.

• An agricultural drought is caused when there is insufficient moisture for crop production.

• A hydrological drought is caused when water reserves in the lakes and reservoirs fall below normal.

• The Great Leap Forward famine that occurred in 1958–61 in China is regarded as the largest famine of all time.

Gift of the Nile

For thousands of years, the Egyptians referred

to the annual flooding of Nile River as the

“Gift of the Nile.”

Earthquake

An earthquake is a sudden vibration of the planet’s surface. The movements of tectonic plates deep inside Earth cause earthquakes. Earthquakes can last from a few seconds to a few minutes. They can be very mild or cause great destruction.

Charles Richter, in collaboration with Beno Gutenberg, developed the Richter scale in 1935.

Richter Magnitudes

Earthquake Effects

Less than 2.0 Micro-earthquakes, not felt.

2.0–2.9 Generally not felt, but recorded.

3.0–3.9 Often felt, but rarely causes damage.

4.0–4.9 Noticeable shaking of indoor items, rattling noises. No significant damage.

5.0–5.9 Can cause major damage to poorly constructed buildings over small regions. At most, slight damage to well-designed buildings.

6.0–6.9 Can be destructive in areas up to about 99 miles across in populated areas.

7.0–7.9 Can cause serious damage over larger areas.

8.0–8.9 Can cause serious damage in areas over several hundred miles across.

9.0 or greater Devastating in areas several thousand miles across.

Seismic Scale

The seismic scale is used to measure and compare the relative severity of earthquakes.

Richter Scale

The Richter magnitude test scale or Richter scale is used to assign a single number to quantify the size of an earthquake. 

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(8) Planet Blue

Water cycle

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Water Cycle

The water cycle is the continuous recycling of water on Earth. Water passes through all its forms in a water cycle. The water cycle is also known as hydrological cycle. Water from water bodies evaporates and mixes with air forming water vapors, which then condense to form clouds. The clouds then bring rain and return the water onto Earth’s surface.

90% of the total fresh water on Earth is found in Antarctica.

• Transpiration is the process by which plants lose water to the air.

• About 90% of atmospheric water comes from evaporation.

• About 10% of atmospheric water comes from transpiration.

• About 86% of the global evaporation occurs from the oceans.

• Water is the only thing in nature that can be a gas, liquid, or solid.

• Advection is the movement of water through the atmosphere.

• About 0.0001% of water on Earth is found in the rivers and streams.

Earth's Water Supply

97% of Earth’s water supply comes from the oceans, icecaps, and glaciers. The remaining 1% comes from fresh ground water.

Parts of the Water Cycle

The water cycle is made up of a few main parts such as evaporation, transpiration, condensation, precipitation, and collection.

Clouds

A cloud is a visible mass of condensed water vapor. Clouds are suspended in the atmosphere or in the higher layers of the atmosphere. Air contains water. When warm air containing water rises, it expands and cools. This cool air condenses into tiny water droplets or ice crystals. These droplets aggregate to form a visible cloud.

 Type of Cloud – Appearance – Altitude (height)

                                           (Genus)

Cumulo nimbus – Can cause lightening, thunder, hail, strong rains, strong winds, and tornados – Near ground up 75,000 feet

Cirro stratus – Thin, wispy, appears in sheets – Above 17,998 feet

Cirrus – Thin, wispy, filamentous, or curly – Above 17, 998 feet

Cirro Cumulus – Small, puffy, patchy and/or with a wave like appearance – Above 17,998 feet

Alto cumulus – Medium-sized puffy, patchy, scattered clouds often in linear bands – 6,499-20,000 feet

Alto stratus – Thin, uniform – 6,499-20,000 feet

Strato cumulus – Brad and flat on the bottom, puffy on the top – Bellow 6,499 feet

Cumulus – Puffy and pilled up – Bellow 6,499 feet

Stratus – Uniform, flat, thick to thin layered clouds with ill-defined edges – Bellow 6,499 feet

Nimbo stratus – Uniform, dark, flat, low, featureless clouds that produce precipitation – Bellow 6,499 feet

 Rain

Rain is a form of precipitation. The process of evaporation and condensation leads to the formation of rain. Water from the rivers, lakes, and oceans evaporate and condense to form liquid droplets, which form clouds. As these droplets become heavy they fall onto Earth in the form of rain.

• Drizzle is a type of rainfall with raindrops having a diameter of less than half a millimeter.

• The wettest place in the world is Mawsynram in India.

• The Atacama Desert of Chile has an average annual rainfall of less than .03 inches.

• One inch of rain falling over an area of one acre has a weight of one ton.

• The biggest raindrops on the earth were recorded over Brazil and the Marshall Islands in 2004, as large as .39 inches.

• The Bergeron process is the scientific explanation of how rain forms and falls.

• Small raindrops are nearly spherical in shape.

Rain Gauge

A rain gauge is used to measure the amount of rainfall.

Types of Rain

There are three general types of rain: orographic, frontal, and convective.

 

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(7) Planet Blue

The Arctic Regions

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Polar Regions

Earth is divided into two Polar Regions: North Polar Region and South Polar Region. These regions are very cold and remain covered with snow for most of the year. They include the Arctic Ocean, Greenland, and Siberia in the North Polar Region and the Antarctic in the South Polar Region.

• In the polar region, the sun never rises in winter.

• In the polar region, the sun never sets during the summer.

• The southern polar region is called Antarctica.

• The northern polar region is called the Arctic.

• Fram Basin at –14,070 feet below sea level is the lowest point in the Arctic.

• Bentley Sub glacial Trench at –8,200 feet below sea level is the lowest point in Antarctica.

• The Arctic poppy and reindeer moss are plants grown in Arctic regions.

• William Edward Parry, a British naval officer, undertook one of the earliest expeditions to the North Pole in 1827.

 Permafrost

The layer beneath the arctic lands is a frozen layer of soil, which is called permafrost.

 Muskeg

Low-lying bushes and grasses in the Arctic regions are known as muskeg.

 Time Zones

Time zones are imaginary divisions of the earth. Earth is divided into 24 time zones, which are separated by 15° in longitude. Each time zone has the same time everywhere within it. The zones start at 0° in Greenwich, England.

• Mean solar time is based on the earth’s rotation relative to the sun throughout the year.

• British Railways established the first time zone in the world on December 1, 1847.

• Greenwich mean time (GMT) was established in 1675.

• Most major countries had adopted hourly time zones by 1929.

• Sanford Fleming divided the world into 24 time zones, each spaced at 15 degrees in longitude.

• The International Date Line is an imaginary line opposite the Prime Meridian, which offsets the date as one travels east or west across it.

 Day of Two Noons

"The Day of Two Noons" is the time zone adopted by the United States and Canadian railroads on November 18, 1883.

Sanford Fleming

In 1878 Canadian Sir Sanford Fleming was the first to propose the system of time zones for the entire world.

 Soil is the surface layer of Earth.

It is a mixture of rock particles, organic matters, and water molecules. Physical and biological agents along with climatic conditions generally form soil. Soil is composed of different layers: organic matter, surface soil, subsoil, and substratum.

Types of Soil

There are 12 types of soil: Alfisols, Aridisols, Entisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodosols, Ultisols, Gelisols, Andisols, and Vertisols.

• Pedology is the scientific study of soil.

• Humus is the top layer of soil, made up mostly of leaf litter and decomposed organic matter.

• Topsoil is the dark-colored layer below the humus, which grow seeds and plant roots.

• The eluviation layer is a light-colored layer beneath the topsoil, which is composed of sand and silt.

• The subsoil is the layer beneath the eluviation layer, made of clay and mineral like iron, aluminum oxides, and calcium carbonate.

• The regolith is the layer beneath the subsoil, which consists of slightly broken-up bedrock.

• Bedrock is the layer beneath all the other soil layers.

Composition of Soil Sample

An average soil sample consists of 45 percent minerals, 25 percent water, 25 percent air, and 5 percent organic matter.

 Pedology is the scientific study of soil.

• Humus is the top layer of soil, made up mostly of leaf litter and decomposed organic matter.

• Topsoil is the dark-colored layer below the humus, which grow seeds and plant roots.

• The eluviation layer is a light-colored layer beneath the topsoil, which is composed of sand and silt.

• The subsoil is the layer beneath the eluviation layer, made of clay and mineral like iron, aluminum oxides, and calcium carbonate.

• The regolith is the layer beneath the subsoil, which consists of slightly broken-up bedrock.

• Bedrock is the layer beneath all the other soil layers.

 Types of Soil

There are 12 types of soil: Alfisols, Aridisols, Entisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodosols, Ultisols, Gelisols, Andisols, and Vertisols.

 Continents

 Earth is divided into large pieces of continuous land masses, known as continents.

Continents cover around 29 percent of Earth’s total area. Asia, Europe, North America, South America, Australia, Africa, and Antarctica are the seven continents. Asia is the largest and Australia is the smallest continent.

 Total Number of Continent Plates

The current continental and oceanic plates include: Eurasian plate, Australian-Indian plate, Philippine plate, Pacific plate, Juan de Fuca plate, Nazca plate, Cocos plate, North American plate, Caribbean plate, South American plate, African plate, Arabian plate, Antarctic plate, and Scotia plate.

 • Alfred Wegener, a German geologist and meteorologist, first proposed the theory of continental drift in 1912.

• The continental drift states that the seven continents were formed from a single land mass or super continent, Pangaea.

• During the Jurassic period, Pangaea started to break up into two smaller super continents, called Laurasia and Gondwanaland.

• Modern-day continents formed by the end of the Cretaceous period.

• Plate tectonics theory states that the earth’s plates are moving constantly at a rate of about 3.93 inches per year.

 SUN

 The sun is the source light, heat, and other forms of energy on Earth. All weather phenomena occur due to uneven heating of Earth by the sun. This causes temperature differences, which lead to global wind, cloud formation, rain, snow, and thunderstorms.

The sun also influences the magnetic properties of the upper atmosphere of Earth, which affects our communication and energy systems.

• Solar energy reaches Earth in less than 9 minutes.

• About 34% of the solar energy reaching the troposphere is reflected back into space by clouds, dust, and chemicals.

• Solar radiation reaches Earth's upper atmosphere at a rate of 1,366 watts per square meter.

• A Trombe wall is a solar heating and ventilation system.

• A solar box oven traps the sun's energy to cook food.

• In 1767 Horace de Saussure made the first known western solar oven.

• Solar cells generate electricity from sunlight.

 Use of Solar Energy

Solar energy can be used in a number of applications such as heating, electricity generation, and desalination of seawater.

 Natural Greenhouse Gases

Natural greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and ozone. The sun is the source light, heat, and other forms of energy on Earth. All weather phenomena occur due to uneven heating of Earth by the sun. This causes temperature differences, which lead to global wind, cloud formation, rain, snow, and thunderstorms. The sun also influences the magnetic properties of the upper atmosphereof Earth, which affects our communication and energy systems

 

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(6) Planet Blue

NASA IMAX: The Earth - Blue Planet

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Mapping the Earth

Earth has been mapped by drawing imaginary lines on its surface. Mapping has helped us in getting information about places on Earth.

The imaginary lines drawn on Earth’s surface are the equator, the latitudes, and the longitudes. They help in the determination of north and south on the globe or map. They are measured in degrees.

Cartography

 Cartography is the science of making maps. People who create maps are known as cartographers.

 • The oldest known map was found on a 4,300-year-old Babylonian clay tablet.

• The Greeks had advanced knowledge of cartography.

• Anaximander was the first Greek to create a map of the world.

• Ptolemy, in around 150 CE, made a world map, which depicted location in terms of latitude and longitude.

• Maps became widely available after the invention of printing in the 15th century.

• In 1508, Rosselli's World Map was the first map to show the entire globe.

• Gerardus Mercator of Belgium was a leading cartographer in the mid-16th century.

 Map after World War II

 The use of aerial photography after the Second World War led to the development of modern cartography

 Equator

 The equator is na imaginary line drawn around the center of Earth. It divides Earth’s sphere into Northern Hemisphere and Southern Hemisphere. The length of the equator is about 24,901.55 miles. The equator passes through 13 different countries.

 Launch Pad

 Launch points for rockets to space are usually near the equator because there is more centrifugal force on the equator than in any other place on Earth.

 Equatorial Countries

 The equator passes through São Tomé and Príncipe, Gabon, Republic of the Congo, Democratic Republic of Congo, Uganda, Kenya, Somalia, Maldives, Indonesia, Kiribati, Ecuador, Colombia, and Brazil.

 • The equator is the longest line of latitude on Earth.

• The equator is located at zero degrees latitude.

• The sun is directly overhead at noon at the equator on the two equinoxes: March and September 21.

• The rate of sunrise and sunset is quickest in places near the equator.

• Volcán Cayambe in Ecuador is the highest point on the Equator.

• The word “equator” is derived from latin aequare meaning to equalize.

 Tropical Zone

 The tropical zone is the zone between the Tropic of Cancer and the Tropic of Capricorn. It lies between latitudes 23°27' north and 23°27' south. These places experience a very hot and humid climate and receive heavy rainfall. The Tropical zone covers around 40 percent of the earth’s surface.

 Subdivision of Tropic Zone

 The tropic zone is subdivided into three major zones: humid tropics, wet-dry tropics, and dry tropics.

 Agricultural Products

 Agricultural products grown in tropical regions include rubber, tea, coffee, cocoa, spices, bananas, pineapples, nuts, and lumber.

• Tropical zone countries include India, China, Australia, Africa, and countries of Central and South America.

• Humid tropics receive around 40 inches of rainfall per year.

• Rainforests lie in the humid tropics.

• Wet-dry tropics receive between 10 and 80 inches of rainfall per year.

• Savannah grasslands are found in the wet -dry tropics.

• Dry tropics receive less than 10 inches of rainfall per year.

• Xerophilous plants are found in dry tropics.

 Agricultural products grown in tropical regions include rubber, tea, coffee, cocoa, spices, bananas, pineapples, nuts, and lumber.

 Temperate

 The temperate zone is found between the Tropic of Cancer and the Arctic Circle in the Northern Hemisphere and the Tropic of Capricorn and the Antarctic Circle in the Southern Hemisphere. The climate is not extreme in this zone. The weather at times is quite unpredictable with rain and low temperatures being common in the summers.

 Temperate Zone in Northern Hemisphere

 In the Northern Hemisphere, the temperate zone includes countries such as Russia, China, Korea, the United States, Canada, and Japan.

 Temperate Zone in  Southern Hemisphere

 In the Southern of Hemisphere, the temperate zone includes countries, such as Chile, Australia, and New Zealand.

 • The temperate zone has two main types of climate: maritime and continental.

• Regions of Western Europe and western North America experience a maritime climate.

• The Rocky Mountains in North America separate the maritime climate of the west from the continental climate of the east.

• In Europe, the Alps separate the maritime climate of the west from the continental climate of the east.

• Greek scholar Aristotle was the first to propose the idea of a temperate zone.

• Major tree species of the temperate zone include oak, elm, beech, chestnut, and maple.

 Temperate Zone in Northern Hemisphere

 In the Northern Hemisphere, the temperate zone includes countries such as Russia, China, Korea, the United States, Canada, and Japan.

 

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(5) Planet Blue

Inside the Earth

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Inside Earth

The inside of Earth is made up of four layers. The crust and the mantle are the outermost layers, while the outer core and the inner most core form the inner layers.

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(4) Planet Blue

 Reveal Earth's Atmosphere

Atmosphere

Earth’s Atmosphere

The atmosphere is the thin layer of gases that surrounds Earth. This layer protects the earth from the harmful rays of the sun and keeps it warm.

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(3) Planet Blue

NASA REVEALS REAL SIZE OF THE EARTH IS BIGGER than first thought

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Shape and Size of Earth

 Earth is almost spherical in shape with flattened poles and a bulging equator. The circumference of Earth around the equator is larger than at the poles. The diameter of Earth at the poles is about 7,899.83 miles, but around the equator, it is about 7,926.41 miles.

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