Sce 201 (marine Science)

Marine Science

Chemical & Physical Properties of Water Distribution of the Earth ’ s Water The Hydrologic Cycle

Marine Science (Oceanography) Oceanography (compound of the Greek

words ωκεανός meaning "ocean" and γράφω meaning "to write"), also called oceanology or marine science, is the branch of Earth science that studies the Earth’s ocean including the geological, chemical and physical elements that interact to create the ocean environment.

 

It covers a wide range of topics, including

marine organisms and ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics; plate tectonics and the geology of the sea floor; and fluxes of various chemical substances and physical properties within the ocean and across its boundaries. These diverse topics reflect multiple disciplines that oceanographers blend to further knowledge of the world ocean and understanding of processes within it: biology, chemistry, geology, meteorology, and physics.

Oceanography has been divided into four separate but related branches:  

1.physical oceanography, 2.chemical oceanography, 3.marine geology, and 4.marine biology.

Physical Oceanography (Marine Physics)

deals with the properties of seawater

(temperature, density, pressure, and so on), its movement (waves, currents, and tides), and the interactions between the ocean waters and the atmosphere.

Chemical Oceanography (Marine Chemistry)

h a s to d o w ith th e co m p o sitio n o f se a w a te r

a n d th e b io g e o ch e m ica lcycle s th a t a ffe ct it

Geological Oceanography (Marine Geology)

focuses on the structure, features, and

evolution of the ocean basins.

B io lo g ica lO ce a n o g ra p h y ( Marine B io lo g y )

Marine ecology, also called biological oceanography, involves the study of the plants and animals of the sea, including life cycles and food production.

These branches reflect the fact that many

oceanographers are first trained in the exact sciences or mathematics and then focus on applying their interdisciplinary knowledge, skills and abilities to oceanography. Data derived from the work of Oceanographers is used in marine engineering, in the design and building of oil platforms, ships, harbours, and other structures that allow us to use the ocean safely. Oceanographic data management is the discipline ensuring that oceanographic data both past and present are available to

WATER

WATER Water is the ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many known forms of life. Universal Solvent. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large water bodies,

Chemical and physical properties   Water has several unique physical and

chemical properties that have influenced life as it has evolved. Indeed, the very concept of the Earth as biosphere is dependent on the special physicochemical properties of water.

Water is a tasteless, odorless liquid at

standard temperature and pressure. The color of water and ice is, intrinsically, a very light blue hue, although water appears colorless in small quantities. Ice also appears colorless, and water vapor is essentially invisible as a gas. 

Water is transparent, and thus aquatic plants

can live within the water because sunlight can reach them. Only strong UV light is slightly absorbed.

Since oxygen has a higher electronegativity

than hydrogen, water is a polar molecule. The oxygen has a slight negative charge while the hydrogens have a slight positive charge giving the article a strong effective dipole moment. The interactions between the different dipoles of each molecule cause a net attraction force associated with water's high amount of surface tension. 

The dipolar nature contributes to water

molecules' tendency to form hydrogen bonds which cause water's cohesive properties. 

Water has a high surface tension caused by the

weak interactions, (Van Der Waals Force) between water molecules because it is polar. The apparent elasticity caused by surface tension drives the capillary waves.

Water also has high adhesion properties

because of its polar nature. 

Capillary action refers to the tendency of water

to move up a narrow tube against the force of gravity. This property is relied upon by all vascular plants, such as trees. 

Water is a very strong solvent and is often

referred to as the universal solvent. Substances that dissolve in water, e.g. salts, sugars, acids, alkalis, and some gases – especially oxygen, carbon dioxide ( carbonation) – are known as "hydrophilic" (water-loving) substances, while those that do not mix well with water (e.g. fats and oils), are known as "hydrophobic" (water-fearing) substances.

All the major components in cells (proteins,

DNA and polysaccharides) are also dissolved in water.  Pure water has a low electrical conductivity,

but this increases significantly with the dissolution of a small amount of ionic material such as sodium chloride.

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The boiling point of water (and all other liquids)

is related to the barometric pressure. For example, on the top of Mt. Everest water boils at about 68 °C (154 °F), compared to 100 °C (212 °F) at sea level. Conversely, water deep in the ocean near geothermal vents can reach temperatures of hundreds of degrees and remain liquid. 

Water has the second highest

specific heat capacity of any known substance, after ammonia, as well as a high heat of vaporization (40.65 kJ·mol−1 ), both of which are a result of the extensive hydrogen bonding between its molecules. These two unusual properties allow water to moderate Earth's climate by buffering large fluctuations in temperature. 

The maximum density of water occurs at

3.98 °C (39.16 °F).[11] Water becomes even less dense upon freezing, expanding 9%. This results in an unusual phenomenon: water's solid form, ice, floats upon water, allowing organisms to survive inside a partially-frozen water body because the water on the bottom has a temperature of around 4 °C (39 °F).  

 ADR label for transporting goods dangerously reactive with

water 

Water is miscible with many liquids, for

example ethanol, in all proportions, forming a single homogeneous liquid. On the other hand, water and most oils are immiscible usually forming layers according to increasing density from the top. As a gas, water vapor is completely miscible with air. 

Water forms an azeotrope with many other

solvents.

Water can be split by electrolysis into hydrogen

and oxygen. As an oxide of hydrogen, water is formed when hydrogen or hydrogen-containing compounds burn or react with oxygen or oxygencontaining compounds. Water is not a fuel, it is an end-product of the combustion of hydrogen. The energy required to split water into hydrogen and oxygen by electrolysis or any other means is greater than the energy released when the hydrogen and oxygen recombine.[12]

Elements which are more electropositive than

hydrogen such as lithium, sodium, calcium, potassium and caesium displace hydrogen from water, forming hydroxides. Being a flammable gas, the hydrogen given off is dangerous and the reaction of water with the more electropositive of these elements may be violently explosive. 

Model of hydrogen bonds between molecules of water

Water Distribution on Earth   Water covers 71% of the Earth's surface; the

oceans contain 97.2% of the Earth's water. The Antarctic ice sheet, which contains 90% of all fresh water on Earth, is visible at the bottom. Condensed atmospheric water can be seen as clouds, contributing to the Earth's albedo

Hydrology is the study of the movement,

distribution, and quality of water throughout the Earth. The study of the distribution of water is hydrography. The study of the distribution and movement of groundwater is hydrogeology, of glaciers is glaciology, of inland waters is limnology and distribution of oceans is oceanography. Ecological processes with hydrology are in focus of ecohydrology.

The collective mass of water found on, under, and

over the surface of a planet is called the hydrosphere. Earth's approximate water volume (the total water supply of the world) is 1,360,000,000 km3 (326,000,000 mi3).



A graphical distribution of the locations of water on

Earth.  1,320,000,000 km3 (316,900,000 mi3 or 97.2%) is

in the oceans.  25,000,000 km3 (6,000,000 mi3 or 1.8%) is in glaciers, ice caps and ice sheets.  13,000,000 km3 (3,000,000 mi3 or 0.9%) is groundwater.  250,000 km3 (60,000 mi3 or 0.02%) is fresh water in lakes, inland seas, and rivers.

Groundwater and fresh water are useful or

potentially useful to humans as water resources.  Liquid water is found in bodies of water, such

as an ocean, sea, lake, river, stream, canal, pond, or puddle. The majority of water on Earth is sea water. Water is also present in the atmosphere in solid, liquid, and vapor states. It also exists as groundwater in aquifers.



Hydrologic Cycle   The water cycle (known scientifically as the

hydrologic cycle) refers to the continuous exchange of water within the hydrosphere, between the atmosphere, soil water, surface water, groundwater, and plants.



Water moves perpetually through each of

these regions in the water cycle consisting of following transfer processes: evaporation from oceans and other water

bodies into the air and transpiration from land plants and animals into air. precipitation, from water vapor condensing from the air and falling to earth or ocean. runoff from the land usually reaching the sea.

What is Water Cycle?

It is the continuous movement of water from the surface of the earth, that is the water bodies on surface of the earth to air and vice versa. This is an unending circle of precipitation that is being formed, absorbed and being created in multiple states of matter: solid, liquid and gas.

The processes that are involved in the Water Cycle

are as follows:

 Evaporation- The process of water converted to

water vapor due to the heat of the sun.  Condensation- The vapor cools and the vapor is transformed into tiny droplets of water again as the temperature decreases.  Precipitation- Water comes back to the surface of the Earth in the form of rain, snow and hail.  Run Off- When some water stays on the surface of the earth and the rest flows into the water bodies like rivers, lakes, reservoirs, it is called run-off.  Percolation- When the water on the surface of the earth seeps down underground it is called Percolation. It later forms aquifers in the lowlying regions.

Hydrologic Cycle

In the hydrologic cycle, water is transferred between the land surface, the ocean, and the atmosphere. The numbers on the arrows indicate relative water fluxes.

The present-day surface hydrologic cycle. The numbers in parentheses refer to volumes of water in millions of cubic kilometres, and the fluxes adjacent to the arrows are in millions of cubic kilometres of water per year.

hydrosphere : General nature of the cycle

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(Encyclopædia Britannica)

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The present-day hydrologic cycle at the Earth's

surface is illustrated in . Some 496,000 cubic kilometres of water evaporate from the land and ocean surface annually, remaining for about 10 days in the atmosphere before falling as rain or snow. The amount of solar radiation necessary to evaporate ...

Thank you !!!

Allan Rogelio M. Sobrevilla Jr.

References •MLA style: "hydrologic cycle: present-day surface." Online Art. Encyclopædia Britannica Online. 19  Aug.  2009  < http://search.eb.com/eb/art-1912>. •APA style: hydrologic cycle: present-day surface. [Art]. Retrieved August  19,  2009, from Encyclopædia Britannica Online: http://search.eb.com/eb/art-1912 •MLA style: "Earth: Earth’s environmental spheres." Online Art. Encyclopædia Britannica Online. 19  Aug.  2009  < http://search.eb.com/eb/art-112176>. •APA style: Earth: Earth’s environmental spheres. [Art]. Retrieved August  19,  2009, from Encyclopædia Britannica Online: http://search.eb.com/eb/art-112176

•MLA style: "inland water ecosystem." Encyclopædia Britannica. 2009. Encyclopædia Britannica Online School Edition. 19  Aug.  2009  . •APA style: inland water ecosystem. ( 2009). In Encyclopædia Britannica. Retrieved August  19,  2009, from Encyclopædia Britannica Online School Edition: http://school.ebonline.com/eb/article-70737