Cycles Of The Earth: What You Need To Know
A cycle could be characterized as one total phenomenon or an order of happenings that repeat or get reiterated. To put it differently, it is a time period or a repeating time period, during which certain happenings or events recur in the same order and at identical intervals.
Looking at the planet as a whole, one natural phenomenon that has been manifest from the beginning of this planet is its seasonal cycle. It is this that has sustained life on earth, and has allowed evolution to create the diversity evident all around us. The change in seasons which takes place due to the revolution around the sun causes the earth to experience the four major seasons known as summer, autumn, winter and spring.
Associated with the seasons on the earth, there is an equally important water cycle. The balance of water on earth remains fairly constant over time, but water moves through its three phases of ice, water and water vapor, in conjunction with the changes in weather, temperature and pressure. Water changes its phases by the processes of evaporation, condensation, and precipitation.
Evaporation of water from the different water bodies on the surface occurs due to low pressures and high temperature. The evaporated water condenses into tiny droplets in the form of overhead clouds. A favorable temperature drop or increased pressure causes coalition of the drops into snow, rain or other precipitation, and the water thus returns to earth and subsequently to the water bodies.
However, there are some additional factors, which influence the process; but this, in a nutshell, is the phenomenon that sustains the ecosystems on earth. Apart from purifying and replenishing the land with fresh supplies, it transports minerals to different parts of the globe through sedimentation and erosion. It is also a significant process involved in reshaping the geological features of the earth over a long period of time.
The eleven year cycle of sun spots is another natural phenomenon that affects the climate on earth. It is observed that nearly every eleven years or so, there is an increase or decrease in the number of sun spots on the surface of the sun. For some periods, the sun shows total idleness, when practically no sunspots are visible.
During these inactive periods, little ice ages have been observed on earth, and there is ice atop the land for long periods at low altitudes and normally free flowing rivers freeze over. However, this phenomenon is still under intensive research and an active connection between disappearance of sunspots and weather patterns are yet to be concluded.
An additional cyclic process is experienced by the seas and oceans. Because the earth rotates on its axis, and the moon exerts a gravitational pull, the water bodies experience tides. When the moon is directly overhead, the water level in the seas and oceans rise; the high tide. Other areas, where the water level falls as a result, is said to experience the low tide.
Therefore, every 24 hours and 50 minutes, a part of the earth, when facing the moon, periodically has tidal movements. And it is this, going back through the generations which first developed the daily cycle by which mankind is still working.