Earth*s Oceans

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Earth’s Oceans
By PJ, Mitchel, Karly, and Sophie
Compounds in the Ocean
 Sodium chloride is
the most
abundant
dissolved solid in
the ocean
Oceans
 71%
 Pacific, Atlantic, Indian, Arctic,
Southern
Salinity
 Salinity is the measure of
dissolved salts in a given
amount of liquid
 PPT(parts per thousand)
 Increased through evaporation
 Decreased through added
water
Density
 More salinity= more density
 Evaporation= more density
 Added water= less density
 Deeper/colder= denser
Functions
 Regulates temperatures at different
locations of the earth
 Absorbs and releases thermal
energy more than dry land masses
 Keeps earth at a temperature
suitable for life
Chapter 2 ~ Section 2
Amaan, Patrick, Anna, & Emma
Exploration of the Ocean Floor
 Sonar: Stands for sound navigation and ranging. Technology is based off the echoranging behavior of bats. It used to calculate the depth of the ocean
 Satellite: Satellites from space send images back to Earth which can then be used for
studying the speed and direction of ocean currents
 GeoSat: A military satellite used to measure changes on ocean height
 Piloted Vessels: (Ex) Alvin and Deep Flight. These vessels allow the ocean floor to be
studied with people inside it.
 Robotic Vessels: (Ex) Jason II and Madea. This vessels allow even more deeper exploration
that is controlled robotically, without people.
Continental Margin
 Subdivided into the shelf, slope, and rise
 Continental Shelf
 Slopes gently toward the open ocean
 Location: between the shoreline and the continental slope
 Continental Slope
 Steeply inclined section
 Location: between the continental rise and the continental shelf
 Continues down to flattest part of the ocean
 Continental Rise
 Base of the continental slope
 Gently sloping
 Location: between the continental slope and abyssal plain
Deep-Ocean Basin
 Composed of oceanic crust
 Abyssal Plain: A broad, flat, almost level area of the deep–ocean basin
 Covered by mud and remains of small decomposing marine organisms
 Average Depth: 4,000 meters
 Ocean Trench: A steep, long depression in the ocean floor that runs parallel to a chain of
volcanic islands or a continental margin
 Occur where one oceanic plate is subducted beneath a continental plate or another oceanic plate at
a convergent boundary
 Seamount: A submerged mountain made up of of volcanic material on the ocean floor
 At least 1,000 meters tall
 Form where magma pushes upwards through or between tectonic plates
 Volcanic Island: Seamounts that surpass sea level
Passive Margins vs. Active Margins
Active Margins
 Occurs on active plate boundaries
 Earthquakes occur often here
 Lots of volcanoes
 Ex. West Coast (California)
Passive Margins
 Occurs where there is no active plate
boundaries
 No trenches, volcanoes, seamounts and
earthquakes are not common
 Ex. East Coast of the U.S.
Chapter 3 Section 1
By Caleigh, Lilly, Gabrielle, and Rachel
Global Winds
 Uneven heating of Earth
 Equator vs. Polar Regions
 High-pressure and low-pressure systems
 Convection currents
 Coriolis Effect = curving of wind direction
Global winds and wind belt
Wind Flow and Interaction
 Northern Hemisphere
 Clockwise
 Southern Hemisphere
 Counter-Clockwise
 From high to low
 Surface currents
 Surface temps
 El Niño
Global Wind
Flow
Coriolis Effect
 Curving of objects from a straight path
 Wind and surface currents move in curved paths
 Caused by Earth’s rotation
 Northern- clockwise
 Southern-counterclockwise
 Goes from high to low pressure
Deep Currents
Deep currents- A streamlike movement of ocean water far below the surface
 Not controlled by the wind
 Affected by the oceans temperature and Salinity
 Salinity is the amount of dissolved solids in a liquid
 Decreasing temperature and increasing salinity increases waters density
How they form
 Decreasing temperature
 Cold air cools the water molecules causing them to slow down and move closer together
 Causes volume to decrease and become denser
 Increasing Salinity through freezing
 When ice forms on top of the water, the dissolved solids are squeezed out
 This increases salinity and increases density
 Increasing Salinity through evaporation
 When water is evaporated it leaves behind dissolved solids
 This makes the water denser
How currents work
 Surface currents carry warm less dense water to the polar regions
 Warm water replaces colder dense, water that sinks to the ocean floor
 Deep currents carry colder water along the ocean floor to polar regions
 Water from deep currents rise and replace surface currents
Ocean Layers and Currents
By Jaycee Blythe and Caroline Whinney
Temperature Zones
Surface
Zone
Thermocline
Deep Zone
Surface Zone
 Warm, top layer
 300 meters below sea level
 Sunlight heats top 100 meters
 Mixes with cooler water below
Surface Zone
Thermocline
Thermocline
 Second layer
 300 meters to 700 meters
 Temperature drops faster than
other two zones
Deep Zone
 Bottom layer
 From 700 meters down
 Cold, unchanging temperature
 1-3 degrees Celcius
Deep Zone
Surface Currents
What controls their movement?
Causes of
Surface
Currents
Global Winds
Coriolis Effect
Continental
Defection
Global Winds
Caused by uneven heating
of the Earth which leads to
differences in pressure
Coriolis Effect
Straight
Curved
Continental Deflection
Movement of Surface Currents in
Hemispheres
Science Chapter 3.2:
Oceanography
Surface Currents, Climate, Upwelling, El Nino
Surface Currents/Climate
 Surface Currents
 Horizontal, stream-like movement of water that occur near or at the surface of the ocean
 Caused by global winds, continental deflection, and the Coriolis affect
 Climate
 Weather in a area over a long period of time
Effects of Surface Currents on Climate
 Temperatures of surface currents vary based on location
The California Current keeps
the climate along the West
cooler than inland climate
year round
Warm-Water Currents:
 Warmer climate: increased humidity
Cold-Water Currents:
 Colder climate: drier atmosphere
The Gulf Stream current transports warm
water from the equatorial region to the
British Isles, warming the previously
cooler climates of the North Atlantic
El Niño
 El Nino: a change in the water temperature in the Pacific Ocean that produces a warm current
 Causes of El Nino
 Produced every 2-12 years due to a reduction in intensity of the Trade Winds
 Less warm water is transported from the southern Pacific to the western Pacific
 Negative Ramifications
 There is no upwelling on the coast of South America
 The coast of South America becomes deficient in nutrient-rich material
 The western Pacific undergoes a series of droughts and experiences cold conditions
 The eastern Pacific is subject to heavy precipitation
 Significance
 Scientists can prepare the denizens of coastal regions that irregular weather is to be expected
Upwelling
 Upwelling: a process in which cold, nutrient-rich water from the deep ocean rises to the
surface and replaces warm surface water
 Upwelling is initiated by global winds blowing warm surface currents out to sea
 When cold water rises to replace the warm water, it brings up nutrient-rich material with it that
benefits plankton, and in turn, nekton
Chapter 3, Section 3
Waves
Erin McGovern and Olivia Luff
Parts of a wave
Amplitude- ½ of the wave height
Crest- the highest point of a wave.
Trough- the lowest point of a wave.
Wave height- the vertical distance between
the crest and trough of a wave.
Wave length- the distance between two
adjacent wave crests, or wave troughs.
Why do waves change as they approach the
shore and how?
• Deep water waves become shallow water waves when they reach depths of less
than ½ their original wavelength.
• Volume remains the same; consequently, the wave height must increase.
What are waves on the surface of the Earth
caused by?
 Surface current- a horizontal movement of ocean water that is caused by wind and that occurs at or near the
ocean’s surface.
Causes:
 The Coriolis effect- the Earth’s rotation causes wind and surface currents to move in curved paths rather than
in straight lines.
 Continental deflections- when the surface currents meet continents, the currents deflect, or change direction.
 Global winds- Different winds cause currents to flow in different directions.
Tsunami
 Tsunami- a giant ocean wave that forms after a volcanic eruption,
submarine earthquake, or land slide.
Causes:
 Volcanic eruptions, submarine earthquakes, and land slides cause
the trigger of tsunamis.
How are tsunamis different from wind driven waves?
 Tsunamis are created from seismic activity, while normal surface
waves are effected by global winds, the Coriolis effect, and
continental deflections.
Tides
Abbey Iafolla, Julia Gleason, Lauren Achenbach, Emma Osilka
What are tides?

Daily changes in level of ocean water

Regular pattern

High Tide
High Tide
 Water advances towards shore

Low Tide
 Water recedes from shore
Low Tide
How Often do Tides Change?

Change four times per day

Two high tides

Two low tides
What causes tides?

Gravitational pull of moon and sun

Earth’s rotation

Greater influence: Moon




Closer to Earth
High Tides

Water faces moon

Creates a bulge on both sides due to speed of Earth’s spinning
Low Tides

Water is drawn away from other areas

Less gravitational pull
Takes 24 hours, 50 minutes for Earth to face moon again
Spring and Neap tides
Spring Tides
 Occur twice a month
 Full and new moon
 Causes: highest high tide and lowest low tide
 Sun, moon, and Earth are aligned

Neap Tides
 Occur twice a month
 First and third quarter
 Causes: low high tides and high low tide
 Sun, moon, and Earth form right angle

Spring or Neap Tide occurs every 7
days
What Are Tidal Bulges

Water is pulled towards Moon

Earth’s rotation causes bulge

Causes low tides in between two high tides
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