Transcript Oceans - Humble ISD

Chapter 15
Salinity
 The total amount of
solid material dissolved
in water.
 Measured in Parts Per
Thousand (ppt ‰)
 Average Ocean Salinity =
35‰
 Most of the salt in
seawater is NaCl, or
common table salt.
Where did the salt come from??
 Chemical weathering
and erosion of rocks and
minerals.
 Earth’s interior:
 Gases emitted into the
air by volcanoes
throughout geologic
history
Processes that Affect Salinity
 Less salty
 Precipitation
 Runoff
 Melting ice
 More salty
 Evaporation
 Formation of ice
Temperature and Thermocline
 Ocean temperature is
highest at the surface.
 Thermocline- the layer
of ocean water where
there is a rapid change of
temperature with depth.
 Creates a vertical barrier
for ocean life.
Density
 Mass per volume unit
 Mass ÷ Volume
 Affects water’s vertical
position.
 Factors that affect
density:
 Salinity
 Temperature
Ocean Layers
 Mixed Zone –water is mixed
by waves and circulation
currents and tides
 Transitional Zone –
temperature falls abruptly
 Deep Zone –Little to no
sunlight. Density is the same
as well as temperature.
 Ocean Floor
Classification of Marine Organisms
 Classified by where
they live and how they
move.
 Plankton: float or drift
with ocean currents.
 Nekton: free swimmers
found in all area of the
ocean.
 Benthos: Live on ocean
floor
Marine Life Zone Factors
 Availability of sunlight.
 Distance from shore
 Water depth
Photic vs. Aphotic zones
 Photos=light
 Photic Zone: upper part
of the ocean where light
can penetrate.
 Euphotic: portion of the
photic zone where there is
enough light to support
photosynthesis.
 Aphotic Zone:
 no sunlight
 Deep ocean
Distance from shore
 Intertidal zones:
 Area where land and
ocean meet and overlap.
 Neritic Zone:
 Seaward from the lowtide line to the
continental shelf break.
 Oceanic Zone Beyond the continental
shelf.
Depth of Ocean
 Pelagic Zone
 Open ocean of any depth.
 Benthic zone
 Any sea-bottom surface at
any distance from shore.
 Abyssal zone
 Deep area with high
pressure zones, low temps
and low oxygen levels.
Ocean Productivity
 Primary Productivity is the
production of organic
compounds from inorganic
substances .
 Photosynthesis- uses light
energy to convert water
and carbon dioxide into
glucose.
 Chemosynthesis- uses
chemical energy to create
organic molecules from
inorganic nutrients.
Factors that Affect a Region’s
Photosynthetic Productivity
 Availability of nutrients
 Amount of solar
radiation/sunlight.
Productivity in the Oceans
Productivity in Polar
Oceans
Productivity in Tropical Productivity in
Oceans
Temperate Oceans
High amounts of
nutrients
Small amounts of
nutrients
Winter: Low
productivity. Days are
short and sun angle is
high
Small amounts of
sunlight
High amounts of
sunlight
Spring: Phytoplankton
quickly depleted.
Productivity is limited.
Summer: Strong
thermocline develops so
surface nutrients are not
replaced.
Fall: Nutrients are near
surface when waters are
being mixed due to
winds.
Trophic Levels
 A trophic level is a nourishment level in a food chain.
Tertiary
Consumers:
• Top of the pyramid
Carnivores or
secondary
consumers.
Herbivores or primary
consumers.
Producers/Autotrophs
• Consume the
herbivores.
• Consume the
producers
• Lowest
level
Food Chain vs. Food Web
 Food Chain: sequence
of organisms through
which energy is
transferred, starting with
the primary producer.
 Food Web: group of
interrelated food chains
The Water Cycle
Water gets recycled over
and over again
Image courtesy of US Environmental Protection Agency
What is the Water Cycle?
Transpiration
Evaporation
Condensation
Precipitation
Accumulation
This is the water cycle!
condensation
transpiration
evaporation
accumulation
precipitation
“Transpiration”
the evaporation of water from plants
“Transpiration”
Do plants really sweat?
Plants like me release water
to supply photosynthesis,
bring minerals up from the
roots, and cool ourselves off.
“Evaporation”
The conversion of water from a liquid to a gas
Solar energy drives evaporation of water from the ocean.
The evaporated water changes from a liquid form into
water vapor a gaseous form.
“Condensation”
The transformation of water vapor back into liquid water by cooling
Evaporated water is warmed and rises into the air where
it eventually cools and condenses to form clouds.
“Precipitation”
Rain, hail, or snow falling from the clouds
due to the condensation of water
When clouds become very heavy with
With
enough condensed
get rain!
condensed
water, the water,
water isyou
released
in the form of rain, hail, or snow.
“Accumulation”
The collection of precipitation into rivers, lakes, and oceans.
This completes the water cycle!
This is the water cycle!
condensation
transpiration
evaporation
accumulation
precipitation
Oceans
Characteristics
Features
Life Forms
The World’s Oceans




71% of the Earth’s surface is covered
by water.
The oceans contain 97% of the
earth’s water.
All the oceans and seas are actually
one continuous body of water.
Oceanographers are scientists who
study the ocean and its processes.
Importance of Oceans
• Oceans affect
all living
things—even
those far from
the shore.
• Oceans
provide a place
for many
organisms to
live.
How were the oceans formed?

When Earth was still a young
planet, many active volcanoes
existed. As they erupted, lava,
ash, and gases were released
from deep within the Earth.
One of these
gases was
water vapor.

Formation of Oceans
• Over millions of years, the water
vapor cooled enough to condense
and form clouds. Then torrential
rains began to fall from the clouds.
Eventually, much
of the land was
covered by
water that formed

Oceans
The oceans are the Atlantic,
Pacific, Indian, and Arctic.
 The Pacific Ocean is the
largest ocean.
 The area and volume of the
Pacific Ocean are greater than
the Atlantic and Indian
combined.

Seas

A sea is one of the largest
bodies of salt water, less
than an ocean, found on
the earth’s surface.
 The Mediterranean, Arctic
and Black Sea are really
part of the Atlantic Ocean.
Properties of Ocean Water
Ocean water is a mixture of
gases and solids dissolved in
pure water.
 Oceanographers believe
oceans contain all the natural
elements on Earth.
 85 of 90 have been found in
the ocean.

Major Elements in the Ocean
Ocean water is 96% pure
water.
 Chlorine (1.9) and sodium
(1.1) make up the next
largest concentration of
elements.
 Sodium chloride is table

Salinity


Salinity
describes the
amount of
dissolved salt in
the ocean.
Salinity is
expressed in
parts per
thousand.
Gases in Ocean Water
The most abundant gases in
ocean water are nitrogen,
carbon dioxide and oxygen.
 The amounts of these
elements vary with depth.
They are more abundant at
the ocean’s surface where
sunlight causes more plant
life.

Temperature of Ocean Water
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Warm water holds less dissolved
gas than cold water.
When ocean water is cold, like in
polar regions, it sinks and carries
oxygen rich water to the ocean
depths.
As a result, fish and other
animals can live in deep parts of
the ocean.
Waves
• A wave in water
is a rhythmic
movement that
carries energy
through the
water.
• Waves are
caused by high
winds blowing
on top of the
water.
Tides
• Throughout a day, the water level
at the ocean’s edge changes. This
rise and fall in sea level is called a
tide.
• A tide is a giant wave that can be
thousands of kilometers long but
only 1 m to 2 m high in the open
ocean.
• Tides are created by the
gravitational attraction of Earth and
the Moon and of Earth and the Sun.
• Tides are
created by the
gravitational
attraction of
Earth and the
Moon and of
Earth and the
Sun.
Tides