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  • Continental Drift 2

    #2: Closer to an Answer


    With new technology developed during the world wars, scientists were able
    to make detailed maps of the ocean floor.
    These maps held the secret to how the continents moved.

    The Ridge

    After the Second World War, submarines were available,
    and so was their technology. Once nuclear submarines were developed
    it became important that submariners could navigate safely underwater.
    Although there were plenty of maps showing what the world looked like above
    the oceans, no one knew much about the ocean floor.
    Technology had been developed that allowed the scientists to map the ocean
    floor by bouncing sound waves off it. This is called sonar.
    After the sonar survey was done, maps were made showing the ocean floor
    in great detail. It was soon discovered that an underwater mountain range
    stretched all the way around the earth on the ocean floor.
    It was also noticed that on either side of this mountain range there was a
    very wide trench.

    Magnetic Stripes

    Scientists had known for some time that the earth has not always been
    polarized to the North. Now when you hold a compass the needle points to
    the North. In the past though it has pointed to the South. We know that
    over billions of years the earth has changed its polarity many times.
    Soon after the discovery of the underwater ridge came another discovery.
    This was that the ocean floor is made up of strips of rock with different
    polarities. A map showing the polarity of the ocean floor in black and white
    looks very much like the pattern on a zebra’s coat.
    The black stripes indicate normal polarity, and the white strips indicate
    reversed polarity.

    An important point to remember is that volcanic rock can only be
    polarized while it is still molten. Once it cools its polarity is set,
    and will not change, even if the polarity of the earth changes.

    The Age and Thickness of the Crust

    The final important discovery was that the earth’s crust is the same
    thickness over the entire ocean floor, and that it has very little build
    up of sediment on it. If it had been there for billions of years, it should
    have a thick layer of sediment sitting on top of the rock floor.
    This led scientists to decide that the ocean floor was in fact quite young,
    in comparison to the continents.

    Beginning to Believe

    It had taken 50 years to get this far, but all of a sudden Wegener’s
    theory was making much more sense. Instead of the continents drifting
    through the earth’s crust, scientists began to believe that the earth’s
    crust had pushed the continents apart.

    At first the scientists proposed that new rock was being formed
    along the underwater mountain ridge. They decided that the ridge was a
    weakness in the crust and that magma, from below the earth’s crust was
    being forced upwards through these weak areas and flowing down the sides
    of the mountain ridges as lava. Underwater, lava cools very rapidly,
    so it was becoming solid, and gradually pushing the crust, on either side
    of the ridge away from the mountains. If this could be proved, then it would
    explain how the continents had been pushed apart.

    The Final Proof

    Still there was a problem; nobody could come up with conclusive
    proof that this theory was correct. Then finally the scientists managed
    to put it all together. They put together two more pieces of information
    that had somehow slipped past them, although they had had the evidence for
    some time.

    • The rocks at the ridges were the youngest, gradually becoming older as they moved apart
    • The stripes of polarity on the ocean floor were symmetrical on either side of the ridge.

      • Now it became clear that the new rock was being formed, and pushing the older rock to the sides,
      causing the entire earth’s crust to be pushed apart. Since rock was formed and polarized on both
      sides of the ridge at the same time, the stripes were symmetrical.
      Sometimes there was a wide strip of south polarized rock followed by a narrow strip of
      north polarized rock, and sometimes the strips were the same width.
      The most important thing was that the strips were the same on both sides of the ridge;
      they were like a mirror image of each other.

      So the theory of drifting continents was at least partly correct.
      They had at one time been a single landmass, which had split apart.
      However, they hadn’t drifted across the ocean, through the earths crust,
      as Wegener had thought. Instead they had been pushed apart, with the movement
      of the earth’s crust.

      A Problem

      From Wegener’s theory of drifting continents, we now had a theory of a
      spreading ocean floor. But still there was a problem.
      If all this new rock was being formed, and pushing aside the old rock,
      why wasn’t the earth getting any larger? Where was all this rock going?


         

  • Continental Drift 1

    #1: Fact or Fiction?


    In 1912, when the German Meteorologist and Geophysicist, Alfred Wegener first proposed that the continents had started off as one huge land mass, that drifted apart, most people thought he was crazy. In fact he was almost correct, although he had it just a little bit wrong.

    The Proposal

    Wegener was the first scientist to publish a scientific paper stating
    that the world had originally had only one continent. He wasn’t the first person to think like this,
    just the first one who was brave enough to announce it to the world. Several people had noticed that the
    continents could fit together like pieces of a jigsaw puzzle. This was particularly noticeable with
    the West coast of Africa and the East coast of South America. If you could remove the 4,000 miles of ocean
    that lay between them they would fit together perfectly. There were other things that pointed to the fact
    they had once been joined.


    Mountain ridges on one continent could be matched to mountain ridges on the other.
    The mountains had the same structure and the same type of rocks.
    When you fit the two continents together, the ends of the mountain ranges lined up.


    They also knew that fossils belonging to the same animals and plants could be found on different continents,
    separated by thousands of miles of ocean.


    Wegener, being a meteorologist, also noticed that fossils found in some areas could not
    possibly have survived the climatic conditions there. For instance, some of the fossils found on Antarctica,
    could never have survived the cold conditions there. Those animals and plants must have originally been much nearer the equator.


    What Wegener proposed was that the continents had once belonged to a single landmass,
    which he called Pangaea. He then said that something had caused them to split apart and drift through the oceans,
    until they came to rest in the positions we know.

    The Reaction

    The scientific community was perfectly willing to believe that the continents had once been joined together,
    but they were not willing to believe that they had drifted through the ocean. After all, everyone knows they go right down to the earth’s crust,
    so in order for them to drift, they must have somehow floated on or through the crust.


    Instead, they preferred the theory that somehow the ocean floor kept rising and falling,
    causing it to reach above sea level at times, forming bridges of land. The animals could walk across these bridges
    from continent to continent. The theory was that the continents hadn’t moved, but that the land joining them had long since sunk
    below the oceans. This preferred theory wasn’t very believable either. It didn’t explain why the continents could fit together like a jigsaw,
    or why mountain ranges stopped on one side of the ocean only to start again on the other side.

    Further Investigations and Discoveries

    By the time Wegener died in 1930, most scientists still refused to believe his Pangaea theory.
    Following the two world wars, and the advances in underwater technology that came with them,
    some important discoveries were made. These underwater investigations and their discoveries proved
    that Wegener had gotten the theory more than half right. The answer to how the continents had moved
    could be found beneath the waves on the ocean floor.

    Conclusion

    It is now an accepted fact that the continents once began as a single landmass
    that slowly separated and became the continents that we know today.
    In fact, most people today think that it is fairly incredible that just 40 years ago
    scientists thought this idea was crazy.

  • Colonies #2: The Reasons for Colonization

    There
    were many different ideas about why colonization was a good thing. The
    explorers had to persuade someone to pay for their trips, so they came
    up with reasons why it was a good idea. Here are some of the reasons
    they gave, including money, culture, and religion. 

    Getting Things Cheaply

    In the very beginning it was seen as a way to buy things cheaply. Once the
    explorers discovered how easily they could overpower the natives of most of the
    countries, they decided to take things rather than buy them.

    A Market Place for Goods

    The colonizers had a lot of goods they wanted to sell. They could produce far
    more things than they could sell to their own people. They were always fighting
    with the people around them, so they needed to find new people to sell their
    things to. They also saw it as a way to give the troublesome poor people jobs.
    They could be put to work making things for the expeditions, and things to trade
    and use in the “new” countries.

    Spreading Religion and Culture

    Most of the colonizing countries saw it as their duty to God, to convert the
    native people to their religion. They also thought that the natives were
    savages, and felt that it was their duty to teach them how to behave
    “properly”.

    Somewhere to Dump “Extra”
    People

    There were more people in the European countries than the governments could
    handle. The poor people were always causing troubles, wanting food and clothes,
    and not wanting to pay taxes. The idea was that the countries could send these
    people to the colonies. Since they were poor, they couldn’t afford to pay to go.
    They had their ticket paid for them by a trading company. Then they had to work
    for the trading company for a number of years, without pay, before they were
    free. This was a great way of getting rid of the troublemakers, and at the same
    time, a cheap way of setting up the colonies.

    Another way of getting rid of people who were considered troublesome, was to
    send convicted prisoners to the colonies. The most famous example of this is
    Australia. These colonies were called “penal colonies”. Although a few
    of the people sent to them were truly criminals, most were just poor people,
    accused of doing things like stealing food or clothes for their children.

    Building Armies and Navies

    The Europeans were a very troublesome lot. They were forever fighting with
    one another. Since the colonies had natives, who didn’t want the colonists, they
    were going to have to fight. Colonists who had been fighting natives for years
    would make very good soldiers.

    To get to the colonies they had to use ships, so more ships were built and
    more sailors trained. In times of war these ships and sailors could be used to
    fight in the Navy.

    Glorification of The Country

    At the time that these colonies were being founded, the European countries
    were all still ruled by Kings and Queens. The Kings and Queens had the final say
    on explorations and discoveries, since they paid for them. In order to persuade
    them to agree, the explorers told them how many new subjects (citizens) they
    would rule over, and how much land they would own. They were a pretty greedy
    lot, so they liked the idea.

    Greed

    If you look at all of the reasons that were given, you can probably see that
    the biggest reason was greed. They could buy, or get things cheaply. They could
    sell the things they made. They could take exotic woods and stones to build
    grand houses and other buildings. They could make themselves more important and
    powerful than their neighbors.

    Perhaps the spreading of religion and culture were the only reasons not tied
    to greed. The colonizers really thought that they were doing something good for
    the native people. Even the spreading of religion was tied in some ways to
    power. The Europeans were busy fighting about the “true” religion.
    Each side thought that more people following their religion would prove that
    they were right.

    Have you read part #1 A
    General Overview ?

    Watch out for part#3, coming soon……The Effects of
    Colonization

  • How to Read a Compass

    Finding Your Way

    How to Read a Compass

    In order to know how to read a map and give directions, and how to find out where something is, you need to know how to use a compass. Most people think of a compass as having 4 points, North, South, East and West, but there is far more to a compass than you would think.

    It isn’t enough to tell someone to go right or left, because right or left changes depending on which way you are standing. Stand up now and face the computer screen. Find something on your left. Turn around, with your back to the computer screen and look at the same object. Now it is on your right. How about describing where a building is? Suppose there is a bank, with a post office next to it. Is the bank on the left or right of the post office? That depends on whether you are standing on the street looking at them both, or inside one of them, looking out at the street. As you can probably tell, this isn’t a very good way of describing where a place is at all.


    This is where the compass comes into it. First of all we need to know just what a compass is, and how it works. A compass is a tool that shows direction. It has a small, magnetized needle in it that swings. The needle can swing because it is balanced on a post, or because it is floating on oil or water, sometimes it is balanced and floating at the same time.


    The needle swings so that one end of it is always pointing to the magnetic north pole. Since the needle has two ends the end that points to the north has some sort of mark on it. Sometimes it is colored red, or has N printed on it and sometimes it just has a fancy arrow on the end.

    The compass has four main points, or cardinal points. These are North, South East and West. If you think of a compass like a clock, the North is a 12, East at 3, South at 6 and West at 9. North and South are easy to remember, but East and West are a little trickier. Picture the compass in your head and remember that it spells we, across the middle, so West is on the Left and East on the right, of the compass face as you look at it.



    Take a large circular object, place it on a piece of paper, and draw round it. Mark North, South East and West on the paper, and then mark lines coming from the center of the circle to each of the cardinal points. Imagine that you are standing in the middle of the circle, and you are told to travel North, that’s easy; you just follow the line going North. The same thing happens with the other cardinal points. Now take a marker and mark a point on the circle between North and East. How would you tell someone to find that, if they were in the middle of the circle, and couldn’t see it? You couldn’t say go north or east, since they would end up in the wrong place. This is where the intercardinal points come in. These are the points half way between the cardinal points. They are named for the points they lie between. They always begin with North or South. They are Northeast, Southeast, Southwest and Northwest.



    Now we are almost done. There are eight more points on the compass, with names. They are called the secondary intercardinal points. They lie half way between the cardinal points (N, S, W, & E) and the intercardinal points (NE, SE, SW & NW). They are named according to the points they lie between. The cardinal point comes first, and then the intercardinal point. The first four are:
    North-northeast East northeast East southeast South-southeast

    Can you name the rest?



    Now you can tell someone fairly accurately, how to get to the point that you marked on your circle. Try drawing some more circles, and marking North on them. Then see if you can name the other points of the compass.


    Extra Activity For Older Students

    Degrees on a Compass

    The compass is divided into 360 degrees, the same as any other circle. If north is at 0 degrees, can you say where the other points are, in terms of degrees?


    Hints:

    The degrees increase in a clockwise direction. It is probably easier if you work out all the cardinal points first, then the intercardinal points, then the secondary intercardinal points.

    Check your answers here.


  • Community Helpers

    #1 What Are They?

    In the last few weeks, community helpers have been in the news a lot.
    We have heard stories about firemen, police officers, paramedics, medical personnel
    and construction workers. All of them have been helping the community.
    Community helpers include many more than these people, though.
    To know what a community helper is, first you need to know what a community is.


    A community is made up of different groups of people
    who live and work together. The community has a specific location
    (it is in one place), it has rules and laws that people must follow and
    the people work together to solve their problems. The very smallest unit
    which could be called a community is you r family, then comes your
    neighborhood, and finally the town or city that you live in.
    So what is a community helper?



    A community helper is anyone in the community who helps others by providing
    a service of some kind. The easy ones to think of are the Police Force,
    the Fire Service and the Emergency Medical Services. There are many, many
    more, though. How many can you think of?


    First, think about your own home. Your Mom can be considered a
    community helper. In your family it is probably your mom who cooks the
    dinner, cleans the house, does the laundry and helps in a thousand different
    ways everyday. If no one did those jobs, just imagine what would happen to
    your family, it would stop being a community and become a disaster instead.
    Not all families do have a Mom, and they are still a community, so who does
    all the jobs in those families? Well, there is Dad and Grandma, maybe a
    housekeeper or a gardener, a babysitter, older brothers and sisters,
    the list goes on and on. Everyone can be a community helper.



    Just suppose you clean up your room. It is only your room; you don’t share it with
    anyone. Do you think that would make you a community helper? The answer is
    not really, because you are helping your Mom and yourself but you are not
    helping the whole community. To be a community helper you would have to do
    something that helped everyone, so cleaning the living room would make you
    a community helper.

    Next, let’s think about community helpers in your neighborhood.
    There is the mail carrier, the sanitation workers, maybe a school crossing
    guard, a baker and of course the emergency services, which include the Fire
    Department, Police Department and Emergency Medical Services. Maybe you
    have a health center in your neighborhood. If you do then you also have
    doctors, nurses and dentists working to help your neighborhood community.



    In the biggest community, your town or city, there are many more helpers.
    There are lawmakers and government officials.
    There are construction crews who help keep the roads under
    repair and maintenance crews who fix the streetlights and traffic
    signals to keep our streets safe. There are shopkeepers who provide
    us with the things we need. There are teachers and janitors in school,
    to help us learn in a clean safe place. In restaurants there are chefs
    waiters and waitresses who help provide us with a good healthy meal.
    There are parking attendants. The list goes on and on. Just about everyone
    in the community is a helper in some way. That is what makes a community,
    a group of people working together to make a better place for everyone.


  • Antarctica Facts


    Antarctica is the fifth largest
    continent and lies entirely within the Southern Hemisphere. It has the coldest
    climate on earth. It is also the windiest place on earth. The average annual
    temperature inland is –70 degrees. The lowest temperature ever recorded on
    earth was in the Antarctic, an incredible 128.5 degrees below zero. Now that is
    cold! Cold can do strange things. If you drop a solid steel bar it will shatter.
    That is one of the reasons that humans cannot live there.

    There is no indigenous (native)
    population, but during the summer several thousand people live there in research
    and weather stations. In the winter only a very few brave scientists stay. James
    Cook was the first explorer known to cross the Antarctic Circle, in January
    1773. He didn’t see any land, though. Land was probably first spotted by
    Admiral Fabian von Bellingshausen and M. P. Lazerev 47 years later, in January
    1820. John Davis, captain of an American sealer, was the first person known to
    set foot on Antarctica. He landed at a place called Hughes Bay in February 1821.
    Hughes Bay is on a Peninsula. Many people claim that the first people to land on
    the true continent were Leonard Kristensen and Carsten Borchgrevink, in January
    1895.

    Almost the entire continent is covered
    with ice and snow. If all of the ice were to melt, it is estimated that the sea
    level throughout the world would rise by 200 ft. The ice extends out into the
    ocean, where is it known as an Ice Shelf. The largest ice shelf, the Ross Ice
    Shelf, is larger than the state of Texas, covering 208,000 square miles. As the
    edge of the ice meets the ocean, and the warmer water, huge chunks break off
    forming ice floes. The ice shelves do not get smaller, though, as the ice flows,
    a little like water. Ice behind the shelf keeps pushing the shelf further and
    further, so even as pieces break off it is still huge. .The ice is formed by
    snow. When the snow falls it doesn’t melt. Each year more snow falls and
    compacts the snow below it, turning it into ice. The ice contains 70% of all the
    fresh water on Earth.


    When people describe Antarctica they
    tend to divide it into two different areas, East and West Antarctica.

    East Antarctica is made up of a
    platform of old rocks, with younger rocks on top. The scientists think that the
    platform is about 1,600 ft above sea level. They cannot be sure, because it is
    covered with a layer of ice almost 6,000 feet deep, so measuring the exact height
    of the land is almost impossible. Without the snow and ice it would be a large
    flat plain with two main mountain ranges, one on the coast and one inland

    West Antarctica is south of South
    America. The land in West Antarctica doesn’t reach as high, and in some places
    is well below sea level. All of the ice causes the land to be pushed down. If it
    all melted the land would rise. East Antarctica would be mostly above sea level,
    but West Antarctica would be made of islands in a sea. The highest parts would
    form the islands and the lower parts would form the sea floor. The highest peak
    is found in West Antarctica, called Vinson Massif. It is on the coast and is
    16,000 ft.

    There are a few areas with no ice. These can be found on
    the coast and slopes of the mountains. On warm days the rock heats up and melts
    the surrounding ice and snow. As the water runs off, it goes down into cracks in
    the rocks. Out of the reach of the sun it freezes again and expands, cracking
    parts of the rock away. All of the areas with no ice have piles of boulders and
    rocks formed in this way.

    There are two known active volcanoes in Antarctica. There may be more, but
    only two have peaks above the ice. The highest is called Mount Erebus. It is in
    East Antarctica on the edge of the Ross Ice Shelf. It is strange to think of an
    active volcano beside all that ice.

    Related articles:
    The Weather and Climate in
    Antarctica
    Animals in Antarctica
    Early Explorers in Antarctica
    Penguins

  • How Money Began

    From Bartering to Paper Money.

    You’ve
    probably never thought very much about money. It is just there. When you
    want or need something, you simply take some money and pay for it. That
    wasn’t always the way things were done, before money was invented people
    used to swap things. This was called bartering.


    At first, people used to do direct swaps
    for what they needed. Supposing you had a lot of corn, but no meat, and the
    farmer down the road had a lot of meat but no corn. If that was the case then
    you could agree on a fair swap, and swap corn for meat. If you needed meat, but
    the farmer already had corn, he might not want any more corn, he may want
    something else, perhaps some eggs. If you still wanted the meat, you would have
    to find someone who had too many eggs, and wanted some corn. Of course, this
    system meant that people spent all their days trying to find someone to swap
    with, and they weren’t able to get anything else done. That was when people came
    up with a better idea.

    Instead of a direct swap of one item for
    another people came up with the idea of using one thing to swap for everything
    else. This was the beginning of money. At first, it didn’t look much like money.
    Different people used different things. Some people used beads or crops, or even
    small animals
    .
    Animals and crops weren’t very practical, since you couldn’t keep them in your
    pocket, when you went to the market. The Native Americans used shells, called wampum.
    These were very highly decorated and everyone wanted them. That was important,
    since if no one wanted them, you wouldn’t be able to swap them for anything.

    At the same time as the Americans were
    using shells, people in other countries were using lumps of metal. The biggest
    problem with a lump of metal was that it was hard to break. How could people
    decide what was a fair sized lump for the swap? The Lydian people, who came from
    an area of what is now Turkey, came up with the idea to make coins
    in about 600 BC. They pressed the metal into flat, round pieces, and different
    size coins had differing swapping value. Later they made coins of different
    metals, and each type of coin had a different value.

    Eventually the use of coins caused
    problems, too. It was the same problem as with the animals; the coins were heavy
    and difficult to carry around. Scholars think that the Chinese were the first
    group of people to come up with the idea of using paper
    money. Although paper isn’t worth anything, it is like an IOU letter. The
    paper money was bought by paying for it with coins. So a paper note, that cost
    20 coins to buy, could be used for buying things, to the value of 20 coins.

    This is how money began. We still use
    the same system today. Our coins are made of metal, and paper money is worth a
    certain amount of coins, and can be swapped for coins at the bank.

    Related Links:

    The
    Minting Process Revealed

     

  • Social Studies Articles

    All the articles have moved to a new sub-domain of this site. You can reach it by clicking on any of the links in the index. This index will be updated as new articles are added. For the latest topic, please use this link:

    http://www.funsocialstudies.com


    Geography

    General Physical
    • Five Themes of Geography
    • Location or Place
    • How to Read a Compass
    • Degrees on a Compass

    Continental Drift

    • Continental Drift – Fact or Fiction?
    • Continental Drift – Closer to an answer
    • Recycling
    • Plate Tectonics
    Miscellaneous Places
    • Time Zones
      What Are They and Why Do We Need Them?
    • Surprising Geographical Facts

    Describing the World

    • World Hemispheres
    • World Continents
    • Antarctica Facts
    • Animals in Antarctica
    • Early Explorers in Antarctica
    • Antarctic Climate and Weather

    History

    General US
    • How Money Began
      From Bartering to Money
    • How Writing Began
      From Hieroglyphics to the Internet
    • Colonies – An Overview
    • Colonies – Reasons for Colonization
    • Community Helpers
    • Flags at Half Mast
      Learn why flags are hung at half mast

    Native Americans

    • An Overview
    • The Major Groups
    • The Effects of Colonization
    • Pilgrims and Technology
    Black History Women in History
    • The Big Dipper
      Road to freedom
    • Harriet Tubman
    • Patricia S Cowings
    • Sidney Poitier
    • Joan of Arc
    • Elizabeth Blackwell
    • Valentina Tereshkova
    • Harriet Tubman
    • Patricia S Cowings
    Ancient Egypt Ancient Egyptians

    The Great Pyramid at Giza

    • The Outside
    • The Inside
    • The Sphinx – Guardian of the Tombs
    • Mummification – Why did the Egyptians make mummies?
    • How Mummies Were Made
    • Papyrus – How it was made
    • Hieroglyphics – How Writing Began

    Three Kingdoms

    • Hatshepsut ~ The queen who became a king
    • Akhnaton ~ Rebel or visionary?
    • Tutankhamun ~ why was he important?
    Places of Interest September 11

    The Great Pyramid at Giza

    • The Outside
    • The Inside
    • The Sphinx – Guardian of the Tombs
    • Stonehenge
    • The Leaning Tower of Pisa

    Please read first: Note to Parents

    • World Coming Together

    Cultures

    Holidays General
    • Cultures
    • Guy Fawkes Day
    • St Martins Day
    • Thanksgiving
    • Some Christmas Traditions
    • Hannukah
    • Kwanzaa
    • Eid Al Fitr
    • Origami
    • Paper lanterns
    • When is a Pancake not a Pancake?


  • Animals in Antarctica

    There is very little plant life on
    Antarctica. It consists of small amounts of lichen and moss, and some floating
    plants in the inland seas. Apart from a few insects, all of the animal life
    feeds from the ocean. The largest animal living entirely on the land of
    Antarctica is a mite. It is just big enough to be seen without a microscope. It
    manages to stay alive by producing chemicals very similar to the anti-freeze
    that we put in our cars in winter! The ocean is full of nutrients. Warm water
    rising brings the nutrients up to the surface. Those nutrients along with krill,
    a small shrimp-like animal are the keys to the food chain in Antarctica.

    Fish

    Although there are many types of fish
    in Antarctica, there are not that many and they are small. However, there are
    plenty of cephalopods (octopus and squid). These play an important role in the
    diet of some whales, seals, fish, penguins and other sea birds.

    Birds

    More than 80% of birds in the
    Antarctic region are penguins. Some live on ice floes, while others live on
    land. The Emperor penguin never steps foot on land. It spends almost its entire
    life in the ocean. The female lays her egg on an ice floe, and the male
    incubates the egg on his feet. The male has a special flap of skin to protect
    the egg, and an indentation in his lower body. He lowers the indentation over
    the egg, so the egg is well protected from the cold. The flying birds are mainly
    petrels and albatrosses. They make their nests on offshore islands and rocky
    areas of coastline. The Arctic Tern flies between the North and South Poles. It
    spends from September to March in the Southern hemisphere, enjoying the summer
    there, and from April to August in the summer of the Northern Hemisphere. Each
    year it flies about 18, 500 miles!

    Mammals

    The marine mammals in the Antarctic
    are mostly whales and seals. There are two main types of whale in Antarctica,
    the baleen and the tooth whales. The baleens feed on plankton, and include
    humpback whales, blue whales and sometimes minke whales. The tooth whales
    include the killer whale and the sperm whale. They feed on other mammals, such
    as seals and on fish and even birds when they can catch them.

    The seals are mainly four types: Ross’s seal, which is
    less than 1% of the population, leopard seals, crabeater seal and Weddell seals.
    There are probably about 20 million crabeater seals in Antarctica. They have
    specially adapted teeth for sieving krill from the water. The leopard seals are
    hunters. They are known to eat penguins, other seals and fish.


    Related articles:
    Penguins
    Antarctica

    The Weather and Climate in Antarctica

    Early Explorers in Antarctica

  • World Geography


    World Geography is essential to the proper understanding of the planet we inhabit. A study of this subject must take off with lessons starting from the origin of the earth, its development, its features and its current geographical details.

    The term Geography is derived from the Greek words Ge or Gaea, both meaning “Earth”, and graphein meaning “to describe” or “to write” or “to map.” Geography is the study of the Earth’s characteristics and distribution of life and habitat on it.

    There are four traditional approaches to the study of World Geography:

    1. Spatial examination of natural and human phenomena or Geography as a study of distribution.
    2. Study based on area (places and regions).
    3. Analysis based on man-land interactions and activities
    4. Earth science, which involves the study of the planet, its water world and the atmosphere.

    Originally, Geography had been equated to the subject of cartography and the study of place names. Though both topography and cartography studies are a vital chapter of Geography, they are not synonymous with the subject itself. 

    The subject must include the study of spatial and terrestrial distribution of planetary occurrences and activities and the correlation between humans and their environment. At the same time, it must also involve the study of economics, health, climate, plants and animals of a particular region. This is what constitutes the interdisciplinary subject of World Geography.

    Another important aspect of World Geography is to divide lessons about the world according to its continents. The seven landmasses of the earth and their neighboring islands are generally referred to as the continents. They are North America, South America, Europe, Asia, Australia, Africa and Antarctica. 

    However, there may be some variations as well. For instance, North and South America are often merged into a single continent and Asia is often combined with Europe. Then there are cases where Antarctica is not considered a continent and Australasia or Oceania replace one Australia.

    In order to make World Geography an entertaining subject you can follow these tips:

    1. You can initiate students to make their own dummy passports (with their photographs) just for the fun of it and think of countries they would love to visit while exploring the world map. While they do this, they can check out travel routes, transport details, places of interest etc. of a particular place.
    2. You can use the Internet effectively to impart information about a particular place and encourage students to surf the web for colorful graphics as well.
    3. Students can also have great fun while packing a suitcase with clothes and essentials for the place they plan to visit. While doing this, they can learn about the weather and travel necessities of the countries they are checking out.
    4. Students can design postcards after a study of the tradition, culture, society and history of the place.

    All this and much more can add a lot of fun to the study of World Geography and increase interest in it.