The Oceans

The Oceans

Oceanography is another application of Earth Science and it consists in the study of the oceans and seas. These disciplines are subdivided into four branches: physical oceanography (related with the physical properties of oceans and seas), chemical oceanography (studies chemical properties), biological oceanography (studies the biological and ecological features of these water bodies) and geological oceanography (studies the geological nature of oceans). This multidiscipline science uses other sciences to investigate and understand the natural processes of oceans to know and predict their behavior. For this reason, oceanography studies everything related with these water bodies including their formation, natural processes, their origins, the life there and the interaction of humans with oceans, seas and also gulfs. Therefore, understanding the oceans is important to understand the relationship with other terrestrial phenomena.

Separating the ocean and sea term is important to have a clear picture of who they are. Oceans are very large salt water bodies with particular features that differentiate from continents, and seas are saltwater bodies much smaller than the oceans and usually they are delimited by land or islands. Earth oceans are Pacific (the bigger), Atlantic (an ocean with a S form and extending toward both poles), Indian (with a triangular form), Artic (located in the North Pole) and Antarctic (located in the South Pole), the last two are the smallest. Some of the most important seas of Earth are Mediterranean Sea, Red Sea, Dead Sea, Black Sea, Caribbean Sea, among many others. Gulfs, bays, narrows and inlets are also part of the oceans. Oceans, seas, and ocean ice compose the 97.957% of total volume of water that exists on Earth. In general terms, the greater amount of water of oceans was originated from the melting of the rocks and the impacts of meteors, these and other events cause that the water trapped in the rocks escapes to the atmosphere in form of water vapor and becoming liquid precipitate as rain. The salt in the oceans is the result of physic and chemical weathering of igneous rock of the Earth crust. The relief, depth, composition and slope of the oceans are also studied by oceanographers.

In the oceans many processes occur, all working and contributing to these water bodies at same time. The Hydrologic Cycle is very important to the oceans because it removes and deposits water from and to the oceans, also involving lands. An important process of the oceans is the salinity that is the quantity of dissolved solids in the ocean water. Chlorine and sodium are the major components of ocean water, although there are others components like sulfate, calcium, potassium, bicarbonate, acids and other substances. In areas of high rainfall on land and in the mouth of large rivers the salinity is lower due to discharge of fresh water from runoff. On the other hand, the sea waters near desserts and enclosed seas are high in salinity. The oceanic circulations are another process of these, for example the thermohaline circulation is the movement of depth water generated by the salinity and temperatures, these circulations distributes the water of the Atlantic Ocean to the rest of the oceans and brings oxygen from surface to depth areas. Surface circulation is the most important and is driven by the winds. These circulations influence the atmosphere and therefore affect the weather, generating most of the atmospheric phenomena. Tides and waves are natural processes of oceans and seas; the tides are the horizontal and vertical movements of the water caused by the gravitational forces of the Moon and Sun, every day and depending on the position of the Moon in regard to respect the Earth there are high and low tides. The waves are energy or a periodic disturbance that moves from one part to another over the surface of water, these are generated offshore and arrive to the coast generating breaking waves.

Oceanographic biology is an important part of this discipline. This studies all the life and ecosystems that exists in these water bodies. The marine environment is dominated by some factors like temperatures, depth, salinity, nutrients, acidification, underwater currents, etc. The terrestrial environment, influences the sea and oceans ecosystems, for example, all the nutrients that arrive from lands through rivers are deposited in seas, these nutrients are used by sea plants and other organisms.  The atmosphere also influence in the life of oceans because it provides the majority of gases including oxygen and carbon dioxide.  The oceans harbor life of all kinds and size, from microscopic plants to microscopic animals, also there are the bigger animals of Earth. Into the ocean and seas we have different ecosystems like rocky coasts, the beaches, estuaries, mangroves, marine lagoons, sea grasses, coral reefs, polar zones and also there is life in the deepest areas of the oceans. The majority of these ecosystems have a direct relation with land and therefore with the organisms and humans that live here. In geological terms the oceans plays a very important role, the majority part of sand is originated in the seas, also part of the rocky coast is formed due to the energetic action of waves and these rocks are composed of death sea organisms.

          Only the 5% of the oceans have been explored by humans. We can make an important connection between the humans and the oceans. Throughout our history, human society has been influenced direct or indirectly by oceans and seas. Many historical events have been carried out thanks to these water bodies; example of this was when the European arrives to America from the fifteen century. Also, in the actuality these are used as communication routes, to bring and carry all kinds of merchandise and people, therefore is an important part of tourism. Also are used to realize investigations, as food source, the film industry use it as a setting for movies, in addition it is are part of the economic and political situation of all countries surrounded or boarded by oceans and seas. All these human activities, including those made inland generate pollution that affects adversely the entire ocean, specifically, the organisms and even we. As the weather is influenced by oceans, these can help to produce atmospheric phenomenon like hurricanes, the same that affects the humans, but are an essential part of nature. Keeping and preserving the oceans and seas not only will help to maintain the entire organisms that live there, also will maintain the life in lands and therefore our own life.

References:

Information:

Alonso J., Serie Naturales. (1998). Descubrimiento 9 Ciencia Integrada.         

            Puerto Rico: Ediciones Santillana, Inc.