Oceanography Oceanography is the study of all aspects of the marine environment To do this we need to use many different sciences Often times the knowledge of multiple sciences is needed to see how each aspect works together ID: 653985
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Slide1
Chapter 1
EQ: 1. How did the oceans form? 2. Where are the major ones located? Slide2
Oceanography
Oceanography
is the study of all aspects of the marine environment.
To do this, we need to use many different sciences.
Often times, the knowledge of multiple sciences is needed to see how each aspect works together. Slide3
OceanographyBiology
Marine life, Adaptations, fisheries
Chemistry
Seawater composition, Pollutants, Density, temperature changes
Physics
Waves, currents, pressure changes, light, sound
Geology
Plate tectonics, sediments, coastlines
Geography
World climates, wind belts, current systems
Astronomy
Formation of earth, origins of oceans, tidal cycles and forcesSlide4
Formation of Earth and the Solar System
Nebular hypothesis
– all bodies in the solar system formed from nebula
Nebula
= cloud of gases and space dustMainly hydrogen and heliumSlide5
Nebular Hypothesis
Gravity concentrates material at center of cloud (Sun)
Protoplanets
form from smaller concentrations of matter (eddies)Slide6
Protoearth: Our early earthLarger than Earth today
Homogeneous composition
Bombarded by meteorites
Moon formed from collision with large asteroidSlide7
Protoearth
Radioactive heat
Spontaneous breaking apart of atoms
Releases heat energy
Means
protoearth
was HOT
HOT
HOT
!
Gravity pulls matter towards the center of the earth, contracting the matter
Earth is heated from the extra pressure from contraction
This makes
Protoearth
partially melt (lots of lava)
Density stratification
(layered Earth)Slide8
Density Stratification
High density = heavy for its size
Early Earth experienced gravitational separation.
High density materials (Iron and Nickel) settled in core.
Less dense materials formed concentric spheres around core.
Least dense gases left the earth to begin to form the atmosphere Slide9
Earth’s Internal StructureLayers defined by
Chemical composition
Physical propertiesSlide10
Layers by Chemical Composition
Crust
Low-density, mainly silicate minerals
Mantle
Mainly iron (Fe) and magnesium (Mg) silicate minerals
Core
High-density, mainly iron (Fe) and nickel (Ni)Slide11
Origin of Earth’s Atmosphere
Outgassing
– occurred during density stratification
Less dense gases drift up into the atmosphere
Water vapor
Carbon dioxide
Hydrogen
Other gases
Earth’s early atmosphere different from today
Lacks oxygen, would be toxic to us now Slide12
Origin of Earth’s OceansOutgassed water vapor fell as rain.
The first permanent oceans formed 4 billion years ago.
Salinity developed from dissolved rock elements.
Early acidic rain dissolved more crustal minerals than today.Slide13
Development of Earth’s OceansSlide14
DO NOW #1
We have been and will continue to look
at the formation of earth and the oceans, information about each ocean, and where the major oceans and seas are located.
From the first day, what areas of science are we using today? (biology, chemistry, physics, geology, geography, astronomy)Slide15
Life’s Possible Ocean OriginsEarth’s earliest known life forms are
3.5-billion-year-old bacteria fossilized in
ocean rocks.
These are the building blocks for life on early Earth.
There is no direct evidence of early Earth’s environment.Slide16
The Beginning….The world ocean is the most prominent feature on Earth.Oceans cover 70.8% of Earth’s surface.
The origin and development of life on Earth is connected to the ocean.
The oceans have a long history on Earth.Slide17
Earth’s Oceans
Earth has one ocean.
It is divided into four principle oceans, and one other.
Pacific Ocean
Atlantic Ocean
Indian Ocean
Arctic Ocean
Southern
, or
Antarctic OceanSlide18
Ocean Info
a) oceans cover 70.8% of the earth
b) of the major oceans, the Pacific is the biggest
c) the Pacific, Atlantic, and Indian are around the same depth. The Arctic is much shallower.
d) the oceans are deeper than the land is tall. Slide19
Comparing Oceans to Continents
Average
ocean
depth is 3729 meters (12,234 feet)
Average
continental
elevation is 840 meters (2756 feet)
Deepest
ocean
trench is the Mariana Trench at 11,022 meters (36,161 feet)
Highest
continental
mountain is Mt. Everest at 8850 meters (29,935 feet)Slide20
Earth’s OceansPacific Ocean
World’s largest ocean
Accounts for more than half of Earth’s ocean space
World’s deepest ocean
Earth’s largest geographic feature
Named in 1520 by Ferdinand Magellan for his peaceful journey across it. Slide21
Earth’s OceansAtlantic Ocean
Half the size of the Pacific Ocean
Shallower than the Pacific Ocean
Named after Atlas, the Greek Titan
Indian OceanSmaller than the Atlantic OceanSimilar depth as the Atlantic OceanPrimarily in the Southern HemisphereSlide22
Earth’s Oceans
Arctic Ocean
Seven percent the size of the Pacific Ocean
Shallowest world ocean
Permanent layer of sea ice a few meters thickSlide23
Earth’s Oceans
Southern Ocean
or
Antarctic Ocean
Circumnavigates Antarctica
Is really the parts of the Pacific, Atlantic, and Indian Oceans that lie south of 50° S latitudeSlide24
The Seven SeasSmaller and shallower than oceans
Salt water
Usually enclosed by land
Sargasso Sea defined by surrounding ocean currents
Directly connected to the ocean
Before the 15th Century, Europeans considered the seven seas to be the following:Red Sea
Mediterranean Sea
Persian Gulf
Black Sea
Adriatic Sea
Caspian Sea
Indian OceanSlide25
SeasNow that the oceans have been explored further (and we know we are not going to fall off the edge of the earth) there are many more than 7 seas.
Here are some of the top ones:Slide26
1. Mediterranean
2. Red Sea
3. Adriatic Sea
4. Black Sea
5. Caspian Sea
6. Persian Gulf
SeasSlide27
7. Arabian Sea
8. Bay of Bengal
9. Hudson Bay
10. Labrador Sea
11. Gulf of Mexico
12. Caribbean
Sea
SeasSlide28
13. Bering Sea
14. Sea of Okhotsk
15. Sea of
Japan
16. Coral Sea
17. Scotia Sea
18. Weddell Sea
SeasSlide29
Closure:1. Why is Oceanography called an interdisciplinary science? 2. How did the earth form?3. How did the oceans form?