Marine WaterMarine Water

Marine WaterMarine Water

Marine watersMarine waters may be fully  may be fully saline, saline, brackish or almost fresh.  or almost fresh. Marine Marine habitats include those s include those below below spring high tide limit (or  high tide limit (or below mean below mean water level in non- level in non-tidal tidal waters) and enclosed coastal s) and enclosed coastal saline or saline or brackish  waterss

Physical Physical CharacteristicsCharacteristics

SalinitySalinityTemperatureTemperatureDensityDensitypHpH

SalinitySalinity

SalinitySalinity is the saltiness or  is the saltiness or dissolved dissolved salt content of a body of  content of a body of water..

The salinity of seawater is The salinity of seawater is usually 35 parts per thousandusually 35 parts per thousand in most marine areas. This salinity in most marine areas. This salinity measurement is a total of all the measurement is a total of all the salts that are dissolved in the salts that are dissolved in the water. water.

Factors Affecting SalinityFactors Affecting Salinity

The relative amount of evaporation The relative amount of evaporation or precipitation in an area. or precipitation in an area.

Due to a very large river emptying Due to a very large river emptying into the ocean.into the ocean.

The freezing and thawing of ice.The freezing and thawing of ice.

Salinity map showing areas of high salinity (36 o/oo) in green, medium salinity in blue (35 o/oo), and low salinity (34 o/oo) in purple.

TemperatureTemperature

TemperatureTemperature is a  is a physical property of matter that  of matter that quantitatively expresses the quantitatively expresses the common notions of common notions of hot and  and cold..

The temperature of seawater The temperature of seawater varies with the amount of varies with the amount of sunsun that hits that area. This includes  that hits that area. This includes the length of time as well as the the length of time as well as the angle of the sun's rays. The longer angle of the sun's rays. The longer the time and the more direct the the time and the more direct the rays of the sun fall on the ocean, the rays of the sun fall on the ocean, the greater the temperature of greater the temperature of seawater.seawater.

The three layered ocean with the upper mixed layer (yellow), main thermocline (light blue), and deep (bottom) water (deep blue).

The upper mixed layer is all one The upper mixed layer is all one temperaturetemperature but that temperature can  but that temperature can vary from -2 degrees C, at the poles, to vary from -2 degrees C, at the poles, to +30 degrees C, in the tropics.+30 degrees C, in the tropics.

The main thermocline is an area of The main thermocline is an area of rapidly decreasing temperaturerapidly decreasing temperature with  with depth.depth.

Deep (or bottom) water is always Deep (or bottom) water is always one cold temperatureone cold temperature ranging  ranging between -2 to +5 degrees C.between -2 to +5 degrees C.

DensityDensity

The mass The mass densitydensity or  or densitydensity of a  of a material is defined as its mass per material is defined as its mass per unit volume.unit volume.

Temperature, salinity and pressure Temperature, salinity and pressure affect the density of seawateraffect the density of seawater. Large . Large water masses of different densities are water masses of different densities are important in the layering of the ocean important in the layering of the ocean water (more dense water sinks). As water (more dense water sinks). As temperature increases water becomes temperature increases water becomes less dense. As salinity increases water less dense. As salinity increases water becomes more dense. As pressure becomes more dense. As pressure increases water becomes more dense.increases water becomes more dense.

pHpH

pHpH is a measure of the acidity or  is a measure of the acidity or basicity of an aqueous solutionbasicity of an aqueous solution

pH is a measure of the acidity pH is a measure of the acidity or alkalinity of a substanceor alkalinity of a substance and  and is one of the stable measurements is one of the stable measurements in seawater. Ocean water has an in seawater. Ocean water has an excellent buffering system with the excellent buffering system with the interaction of carbon dioxide and interaction of carbon dioxide and water so that it is generally always water so that it is generally always at a pH of 7.5 to 8.5.at a pH of 7.5 to 8.5.

Anything either highly acid or Anything either highly acid or alkaline would kill marine life but alkaline would kill marine life but the oceans are very stable with the oceans are very stable with regard to pH.regard to pH.

Chemical Chemical CharacteristicsCharacteristics

Seawater is mostly Seawater is mostly (~96.5%) water, but it contains (~96.5%) water, but it contains important amounts of dissolved important amounts of dissolved salts (~3.5%), which are mostly, salts (~3.5%), which are mostly, but not all, but not all, sodium chloride, which  chloride, which is identical to is identical to table salt..

Aside from Aside from calcium chloride salts,  chloride salts, seawater also contains sulfates (7.7% seawater also contains sulfates (7.7% of dissolved salts),of dissolved salts),magnesium (3.7%),  (3.7%), calcium (1.2%), calcium (1.2%), potassium (1.1%), and  (1.1%), and minor constituents (0.7%), including minor constituents (0.7%), including trace amounts of inorganic trace amounts of inorganic carbon (0.2%), bromide (0.08%), uranium  (0.2%), bromide (0.08%), uranium (0.00000001%), and gold (similar (0.00000001%), and gold (similar amount).amount).

Six Six elements and  and compounds comprise about 99% of sea salts:  comprise about 99% of sea salts: chlorine chlorine

(Cl(Cl--), sodium (Na), sodium (Na++), sulfur (SO), sulfur (SO44-2-2), ),

magnesium (Mgmagnesium (Mg+2+2), calcium (Ca), calcium (Ca+2+2), ), and potassium (Kand potassium (K++). ).

The chlorine ion makes up 55% of The chlorine ion makes up 55% of the salt in seawater. Calculations the salt in seawater. Calculations of seawater salinity are made of of seawater salinity are made of the parts per 1000 of the chlorine the parts per 1000 of the chlorine ion present in one kilogram of ion present in one kilogram of seawater. seawater.

Some of the important Some of the important atmospheric gases found in atmospheric gases found in seawater include: nitrogen, seawater include: nitrogen, oxygen, carbon dioxide (in the oxygen, carbon dioxide (in the form of bicarbonate HCOform of bicarbonate HCO33), argon, ), argon, helium, and neon. helium, and neon.

References:References:

http://www.kayelaby.npl.co.uk/general_physics/2_7/2_7_9.html

http://www.ehow.com/http://www.ehow.com/list_6116511_sea-water-list_6116511_sea-water-characteristics.htmlcharacteristics.html

http://www.es.flinders.edu.au/http://www.es.flinders.edu.au/~mattom/IntroOc/lecture03.html~mattom/IntroOc/lecture03.html

http://www.marinebio.net/http://www.marinebio.net/marinescience/02ocean/marinescience/02ocean/swcomposition.htmswcomposition.htm

http://www.wisegeek.com/what-http://www.wisegeek.com/what-are-the-chemical-properties-of-are-the-chemical-properties-of-seawater.htmseawater.htm

http://www.marinebio.net/http://www.marinebio.net/marinescience/02ocean/marinescience/02ocean/swcomposition.htmswcomposition.htm

Prepared by:Prepared by:

Steffi Dawn C. IlaganSteffi Dawn C. Ilagan

Ranesa Joyce E. PoliranRanesa Joyce E. Poliran