UNIT 7 – OCEANS AND CLIMATE
CH 15 Ocean Water and Ocean Life
15.1 The Composition of Seawater
Salinity
Salinity is the amount of solid material dissolved in water. It is expressed in __________ per __________________
which is abbreviated _____________. The average salinity of seawater is _______________. Most of the salt in
seawater is ___________ ______________, common table salt. The salt comes from ________________
______________ of rocks on the continents. The second major source of elements found in seawater is from Earth’s
______________________.
Processes Affecting Salinity
 Processes that Decrease Salinity
o __________________________________________________________
o __________________________________________________________
o __________________________________________________________
o __________________________________________________________
 Processes that increase salinity
o __________________________________________________________
o __________________________________________________________
Ocean Temperature Variation
The ocean’s surface water temp varies with ________________________________________________________
which is primarily a function of latitude.
Temperature Variation with Depth
The _____________________________ is the layer of the ocean water between about 300m and 1000m where
there is a rapid change in temp. The ______________________________ is a very important structure because
it creates a barrier to marine life.
Ocean Density Variation
Density is defined as _____________________ per unit ______________________.
Factors Affecting Seawater Density
-------------------------------------------------_______________________________
The __________________________ is the layer of ocean water between about 300m and 1000m where there is
a rapid change of density with depth.
Ocean Layering
Mainly a 3 layer structure in ocean:
1. ___________________ ___________ - shallow (300-450m), zone of mixing, sun-warmed zone
2. ____________________ _____________ - between surface layer and deep zone, thermocline and
pyncocline
3. ______________ _____________ - sunlight never reaches this zone, temps just a few degrees above
freezing, constant high-density water
CH 16 The Dynamic Ocean
16.1 Ocean Circulation
Surface Circulation
__________ _______________ is the mass of ocean water that flows from one place to another.
Surface Currents
 Surface currents are ______________ of _________________ that flow ________________________ in
the __________ part of the ocean’s ________________.

Surface currents develop from _____________ between the ocean and the _________ that blows across
its surface.
Surface Circulation
 Gyres
o Gyres are huge circular-moving current systems that dominate the surfaces of the oceans.
o The _________________ ________________ is the deflection of currents away from their original
course as a result of _________________ __________________. In the northern hemisphere, currents
deflect to the ________________.
 Ocean Currents and Climate
o When currents from low-latitude regions move into higher latitudes, the transfer _________ from
warmer to cooler areas on Earth.
o As cold water currents travel toward the ______________, they help moderate the warm temperatures
of adjacent land areas.
 Upwelling
o Upwelling is the rise of ________ ___________ from deeper layers to replace warmer surface water.
o Upwelling brings greater concentrations of ________________ _____________, such as nitrates and
phosphates to the surface.
Deep-Ocean Circulation
 Density Currents
o Density currents are ______________ currents of ocean water that result from the ____________
differences among water masses.
o An increase in seawater density can be caused by a __________ in ___________________ or an
______________ in _________________.
 High Latitudes – most water involved in deep-ocean currents begins in high latitudes at the surface
 Evaporation – density currents can also result from _____________ _____________ of ocean water due to
evaporation
 A Conveyor Belt – ocean circulation is similar to a conveyor belt that travels from the ______________
_________ through the ____________ and ______________ ____________ and back again.
16.2 Waves and Tides
 Wave Characteristics
o Most ocean waves obtain their energy and motion from the ___________.
o __________ _______________ is the vertical distance between the trough and crest.
o _______________________ is the horizontal distance between two successive troughs.
o ______________ ________________ is the time it takes one full wave – one wavelength – to pass a
fixed position.
o ________ is the distance that the wind has traveled across open water.
o The height, length and period that are eventually achieved by a wave depend on 3 factors:
____________________, _______________________________________________________ and
____________.
 Wave Motion
o ______________ ______________ motion allows energy to move forward through the water while
while the individual water particles that transmit the wave move around in a __________.
 Breaking Waves
o Changes occur as a wave moves onto shore
o As the wave touches the bottom, wave speed ______________. The decrease in wave speed results in a
_________________ in wavelength and an _______________ in wave height.
Tides
 __________ are daily changes in the elevation of the ocean surface.




Ocean tides result from the __________________ __________________ exerted upon Earth by the ______ and,
to a lesser extent, by the ________.
Tide-causing Forces
o The force that produces tides is _____________________.
Tidal Cycle
o _________ ________ is the difference in height between successive high and low tides.
o _____________ ___________ are tides that have the greatest tidal range due to the alignment of the
Earth-moon-sun system.
o __________ _____________ are tides that have the lowest tidal range, occurring near the times of the
first-quarter and third-quarter phases of the moon.
Tidal Patterns
o 3 main tidal patterns exist worldwide: ______________________________,
_________________________, and ______________________________________.