What are the features of tooth whales?

Whales are commonly seen in the frigid seas of the Arctic. You must have seen pictures of whales or movie about them, and y will agree that they are most impressive. There are actually two types of whales - the toothed whales and the baleen whale both of which are found in the Arctic Circle. 

Toothed whales have teeth in the upper and lower jaw! With which they seize their prey. They feed on all manner of marine animals including squid and fish, including squid, fish, as well.

Why are baleen whales different from toothed whales?

Baleen whales are in the same family as their cousins the toothed whales, but they have baleens instead of teeth. Hundreds of long baleen plates grow down on either side from the roof of their mouths. Popularly called ‘whalebones’, baleens are actually flexible strips of keratin, the same substance that is found in human hair and fingernails. The baleen plates are edged with hairy fibres that create a sieve to strain prey like knit, plankton, and other small organisms from water.
The whale takes a mouthful of water containing its prey, closes its mouth, and forces the water out between the baleen plates with its tonge. The food is trapped and swallowed. Unlike teeth, baleen continues to grow throughout a whale’s life, as the ends are always wearing out.

Another difference between these two kinds’ whales is that baleen whales are generally large animals. They are not predators. This means that they do not go hunting for the food. In contrast, toothed whales are active predators, usually moving in pods to find prey, which they grasp with their teeth and swallow whole. 

Which are the countries of the Arctic?

There is no Arctic continent or landmass - there is only the Arctic Ocean that is bounded by the coasts of three continents - Europe, Asia and North America. 

The Arctic Circle passes through seven countries that have a considerable portion of land within the Arctic Circle. The countries are the United States of America, Greenland, Canada, Russia, Norway, Sweden, and Finland. Of these, Russia has by far the largest area. Iceland has a tiny region - less than one square km - inside the Arctic Circle. 

All these countries, except for Finland and Sweden, which do not have an Arctic coastline, face each other directly across the Arctic Ocean. 

Some other areas within the Arctic Circle include the Lapland province in Finland, Yukon, the Northwest Territories, and part of Nunavut in Canada. Davis Strait in the Atlantic Ocean, the Island of Grimsey, which is part of Iceland, and the Greenland and Norwegian Seas in the Atlantic Ocean are also within this circle. 

What are the features of toothed whales?

Whales are commonly seen in the frigid seas of the Arctic. You must have seen pictures of whales or movies about them, and you will agree that they are most impressive. There are actually two types of whales –

 the toothed whales and the baleen whales, both of which are found in the Arctic Circle.
Toothed whales have teeth in their upper and lower jaws with which they seize their prey. They feed on all manner of marine animals including squid and fish, as well as mammals.

 Whales must come up to the surface of the water to get air. The air is breathed in and out through their nostril or ‘blow- hole’, which is on their back. Toothed whales have only one blowhole. Sometimes, a whale will swim up to the surface of the water and quickly blow air out of its blowhole, making a fountain of watery mist, called a ‘blow’.

Toothed whales come in all sizes. The smallest are the dolphins and porpoises which are between six and ten feet in length, while the largest is the sperm whale, which can be up to sixty feet long. 

Which are the countries of the Arctic?

There is no Arctic continent or landmass - there is only the Arctic Ocean that is bounded by the coasts of three continents - Europe, Asia and North America.

The Arctic Circle passes through seven countries that have a considerable portion of land within the Arctic Circle. The countries are the United States of America, Greenland, Canada, Russia, Norway, Sweden, and Finland. Of these, Russia has by far the largest area. Iceland has a tiny region - less than one square km  inside the Arctic Circle.

 All these countries, except for Finland and Sweden, which do not have an Arctic coastline, face each other directly across the Arctic Ocean. Some other areas within the Arctic  Circle include the Lapland province in Finland, Yukon, the Northwest Territories, and part of Nunavut in Canada.

Davis Strait in the Atlantic Ocean, the Island of Grimsey, which is part of Ice-
land, and the Greenland and Norwegian Seas in the Atlantic Ocean are also within this circle.

What is a tundra climate?

The tundra is the coldest region in the World. Fierce Winds blow while snow and ice cover the ground even the sea freezes as the temperature gets colder. Sometimes, the strong winds create ‘white outs’ when the snow blows so much that it is hard to see! Whiteouts last for days. The tundra has a short summer that lasts from May to July. During the summer the temperature only rises to about 50 degrees Fahrenheit. The average yearly temperature is only 10 to 20 degree Fahrenheit.
There is very little rainfall or snowfall in a tundra climate less than 10 inches of precipitation yearly. So in fact, the tundra is drier than many of the world’s hottest deserts! 

Why is Greenland the only landmass to have a truly polar climate?

Polar climates are found only in regions where it is freezing all the year round, and Greenland is the only landmass to have a truly polar climate. However, this does not mean that weather conditions are the same along the almost 2735 kilometer-long island. It means that by definition, the whole of Greenland remains within polar climatic limits, where average monthly temperatures do not exceed 50°F. 

Greenland is a large island surrounded by the ocean. Inland temperatures remain at the sub zero level throughout the year, and it never rains here, only snows. In the coastal regions, the land generally thaws in spring and summer and there may even be a little rain. Compared to the rest of the Arctic, Greenland is not a very windy place. There can be many totally calm days - but, at the same time, there are areas of the country that rank as some of the most Windswept in the Northern hemisphere So, the climate of Greenland can be summed up as being dry, windy, and very, very cold indeed!
Polar Regions

Why are the climatic conditions in the Arctic Circle special?

The Arctic consists of ocean surrounded by continental land masses and islands. The central Arctic Ocean is ice-covered round, and snow and ice are present on land for most of the year. The climate within in Circle is very cold, and much of the area is always covered with ice.

The climate of the Arctic, known as the Polar Climate, is characterized by long, cold winters and short, cool summers. Precipitation in the form of snow is low, but heavy winds whip up fallen snow to create the illusion of constant snowfall. The climate is moderated by the ocean, with regions near the Atlantic and pacific oceans having generally warmer temperatures and heavier snowfalls that the colder and drier interior areas.

In the mid winter months the sun never rises, and temperatures can easily reach lows of
-50 F in the higher latitudes. In the summer months, in the Southern regions, 24 hours of sunlight a day melts the seas and topsoil, and is the main cause of icebergs breaking off from the frozen north and floating south, causing havoc in the Shipping lanes of the North Atlantic.

Why is it said that the Arctic Circle does not have fixed latitude?

The Arctic Circle is the invisible circle of latitude on the Earth’s surface at 66°33’ north. It is a geographic ring crowning the globe, and is approximately 2,655 kilometers from the North Pole. However, scientists say the Arctic Circle keeps shifting. 

You know that the Earth rotates on its axis like a spinning top - but it is a spinning top that has a little bit of wobble. 3ecause of this, the Earth’s axis shifts from about 22 to 24.5 degrees every 20,000 years. The 2.5 degrees of axis shift every 41,000 years equals about 320 kilometers of movement in that time, or about 25 feet each year. As a result, the exact location of the Arctic Circle keeps on changing! 

SunDogs

Sundogs are caused by light shining through ice crystals in a cloud -just like light shining through raindrops makes a rainbow. Usually, cirrus clouds in front of the Sun produce sundogs, but other ice clouds may also generate them. Sun- dogs are sometimes so brilliant that dazzled observers mistake them for the Sun. 

What is the difference between the geographic North Pole and the magnetic North Pole?

When we talk about the North Pole, we usually mean the northernmost point on the Earth’s surface. But there are actually two North Poles - the geographic North Pole and the magnetic North pole. The geographic North Pole is located in the middle of the Arctic Ocean, which is constantly covered with shifting sea ice. It is a fixed location at 90 North and is the northernmost point on the Earth, from which all points lie south. 

The magnetic North Pole, on the other hand, is determined by the Earth’s magnetic field. Did you know that the Earth acts like a giant magnet? The Earth’s magnetic North Pole is the point on the Earth’s surface at which the Earth’s magnetic field points vertically downwards. The magnetic North Pole location moves constantly with time. It lies hundreds of miles from the geographic North Pole, and its exact position is constantly shifting. 

Why is it said that the Sun does not set in the Arctic Circle?

Can you imagine seeing the Sun at midnight?

Well if you were to visit the arctic circle in summer, you would see just that1 why does this happen?

You know that the earth’s axis is tilted, and because of this, one pole is inclined towards the sun for six months of the year, and the other pole for the rest of the year. The result is that the pole facing the sun has almost continuous day light for those six months, while pole facing away has almost continuous darkness during that period. 

In the case of the Arctic Circle there is almost continuous daylight during summer and almost continuous darkness during winter. In fact, on June 21st, sun does not set at all, and can be seen even at midnight.

What causes the aurora borealis?

The aurora borealis, which can be seen in the North Pole. They are a stunning display of moving lights that appear like giant series of curtains hanging and waving in the sky. They could stretch from horizon to horizon, and shift through various soft greenish, bluish colors. Do you know that they are caused by two things, the intense activity of the Sun, and the Earth’s magnetic fields?

The Sun emits a constant stream of charged particles, known as wind. As these particles race Earth, most of them are turned aside by the Earth’s magnetic field, and go around the planet. However, some particles leak into the Earth’s upper atmosphere where they collide with atoms produce the colorful displays known as the ‘Northern Lights’.

The same phenomenon occurs. Antarctic region, where it is known as aurora australis or Southern Lights. The display of light takes many shapes as arcs, bands, coronas, curtains which move about with remarkable speed and beauty. 

Why is it said that the Arctic and the Antarctic have many features in common?

Though the Arctic and the Antarctic lie on opposite ends of the globe, they have some features in common. To begin with, both are very very cold indeed. The ice caps that cover them are left over from - Ice Age that covered parts of e Earth a million years ago.

Mirages are another feature that they have in common. Because of tilt of the Earth, sunlight passes through the cold air at a slant. This ending of the rays of light causes fantastic mirages in both the Antarctic and Arctic regions. Halos of light around both the Sum and the Moon can be seen anywhere, but they are most com only viewed in both the Polar Regions.

Halos, sundogs, and moon dogs can be seen both in the Arctic and the Antarctic. Sundogs are the bright areas on the sides of the halos surrounding the Sun, while moon dogs are the bright spots seen on halos that surround the Moon. Many other wondrous phenomena of light can be seen in both the Arctic and Antarctic, including the magical aurora borealis or Northern Lights, and the aurora australis or Southern Lights. 

What are the Polar Regions?

The Polar Regions are the areas that surround Earth’s geographic north and south poles. The area surrounding the North Pole is called the Arctic, and includes almost the entire Arctic Ocean and the northern areas of Europe, Asia, and North America.

The area surrounding the South Pole is called the Antarctic, and includes the continent of Antarctica, and parts of the surrounding Southern Ocean.

The Arctic region extends from the North Pole to the Arctic Circle which is at 66.5°N latitude, while the Antarctic region extends from the South Pole to the Antarctic Circle at 66.5°S latitude. Did you know that regions inside the Arctic and Antarctic Circles can experience 24 hours sunlight on midsummer’s day, and 24 hours of darkness on mid-winter’s day?

A Voyage to a ‘Snow White’ World

Talk about a trip to the end of the world, and you think of the Polar Regions. These are ice-capped regions that surround the Earth’s two geographic poles

As everybody knows, the Earth has two geographic poles - the North Pole and the South Pole. To make an easy comparison, the Arctic is essentially a great ice-covered ocean surrounded by land, and the Antarctic is a gigantic, ice-covered continent surrounded by ocean.

In winter, these seas freeze into a solid pack ice.
These regions are the coldest parts of the world, and the ice, snow and freezing winds make them the most inhospitable, too. Yet, even in these frozen environments, life flourishes.

With the threat of global warming, the polar icecaps are shrinking, which may affect the world’s climatic cond itions and the lives of all living things on Earth? This issue of Tell Me Why takes you on a fascinating voyage to the wonderful ‘ends’ of the Earth.

Why is it not easy to describe the Universe?

When you hear the word ‘Universe’, what do you think of? You think of a large and unimaginable expanse of dust, gas, stars, clouds, galaxies, and life. It is difficult to describe it exactly, because no one knows what it actually consists of. There may be many distant worlds in the Universe about which we know nothing. Even every empty space is part of the Universe, and so are matter, time, and energy.

Some scientists say that if you could look at the entire universe at once, it would look like a giant spider web, made up of billions of galaxies, and trillions and trillions of stars. If you find this a bit too much to grasp, don’t worry! Even the greatest scientists have not yet solved the mystery of the Universe!

 
It is difficult to say how big the Universe is, because we can’t even imagine how big it might be. Our Earth is only a tiny, tiny part of our solar system, and our solar system a tiny part of another system called the ‘galaxy’. Beyond our own galaxy lies a vast expanse of galaxies. There are billions of galaxies, the most dist ant of which are so far away that the light arriving from them on Earth today set out from the galaxies billions of years ago!

Perhaps, all these billions of galaxies put together are still only a tiny part of a larger system.
So, we know that the Universe is bigger than what anyone can imagine, but how much bigger is a quest ion that Man has been asking himself since the beginning of time. The answer is still beyond our grasp, especially as scientists believe that the Universe is still expanding! 

Why is It Possible to Measure Distances From The Stars?

Scientists cannot Stretch a measuring tape from the Earth to a nearby star, so how do they know how far away they are? It’s always been known that the stars are very remote, but it was not until 1838, that the first Star-distance was measured, using the method of parallax by F. W. Bessel.

 A star, viewed from different Points in the Earth’s orbit will shift against its background of more distant stars the deviation in the angle can be used to calculate the distance. Today, scientists use Special cameras fitted into some special types of telescopes to calculate distances. Special types of telescopes are used to Photograph large areas of the sky. Scientists also use instruments like a spectroscope radio telescope, etc. to determine how far a star from Our Earth is. 

Light years are the unit of distances in Space. This sounds like a unit of time, but a light year is actually the distance that light travels in one year Light travels 299 792 km per second. So, a light year is about 9 460 700 000 000 km. It has been calculated that the nearest galaxy is the Andromeda, which is at a distance of 2.2 million light years, from Earth. Did you know that the Sun is positioned only 8 light minutes away from Earth? This is called the light speed. Light takes only 8 minutes to travel to our earth from the sun.