The Movement of Water during the Year - Essay Example

The seasons are a cycle that is brought up continuously throughout every section, whether it is two seasons or four depending on the location.  Places that reside along the equator experience only two seasons, one wet and one dry, because they get an immense amount of direct sun exposure.  This is because of the way the Earth is positioned; this tilt of the Earth’s axis is also what is directly responsible for the four seasons of the most northern and the most southern climates.  Because all things do depend on the sun as it represents a new beginning, like when it arrives in the spring, animals that make their home in a climate with four seasons often follow the sun.  This process is called migration and this cycle can be amazing.  The largest land migration of any animal happens in the spring in Northern Canada when three million caribou march across the tundra.  The spring is also marked by melting sea ice that broadens the deciduous forest and fattens the many waterways that thread their way across the land.

            The movement of water during the year is another significant cycle taking place daily on our planet.  All life is dependent on water and many species spend most of their time searching for and following water, like elephants and buffalo.  The distribution of water also shapes our landscape; where water is prevalent the land is lush and green and where it is sparse the land is dry and barely inhabited.  When this is the case we have desert and, sadly, the amount of land that is covered with desert is growing yearly.  The desert experiences a lack of rain and rain is the source of all freshwater, which is essential to the survival of all species, plants, and animals.  The rain fattens our rivers and streams as the melting of the polar ice does.  It is these rivers that start in the mountains and travel hundreds of miles to the sea, slowing down as they reach the oceans and release the sediment they have collected on their journey and build deltas.  The sediment the rivers gather is from running through the mountains and eroding them, as rivers are the most erosive force on Earth.

            This erosion of the mountains is another important cycle taking place on our planet all the time.  The shifting of continents is a sequence that creates mountain ranges.  The Himalayas were formed 50 million years ago when India collided with Tibet and this vast range is still growing today, it is the Rockies that are eroding.  The rivers and streams that run through the Rockies erode them as well as the 100 000 avalanches they have a year.  It is interesting to view these different mountain ranges going through very different cycles, and yet both ranges affect our environment immensely.  The moisture that evaporates off the slopes of mountains creates clouds which in turn create storms, or rain which adds to the world’s supply of fresh water, thus, feeding all life.  The mountains indirectly help with the survival of species but they are also a safe place for some animals to bring their young into the world.

            One of the animals that finds refuge in the mountains is a bear.  The polar bears have their nurseries in the northern mountain ranges and they must lead their young from these slopes south before the sea ice melts and traps them.  The grizzly bear also shields its young on the sides of mountains as the male grizzly is too heavy to venture this high up and, therefore, unable to harm the cubs.  For, a male grizzly could eat the baby bears if he was hungry enough.  Again, the mother bear must lead her cubs down the mountain to get food before her milk runs out.  A mother bear’s milk is created from her fat deposits which she lives off all winter.  So, the cycle of the bears is very important as they must spend their spring, summer, and fall fattening up to ensure their survival through the winter, which they spend in their den, hibernating.