Transcript The Earth as a System

Earth System Science (ESS)
• The study of the interactions between and
among events and Earth’s spheres
• A relatively new science (1988)
1.1 What Is Earth Science?
 Encompasses all sciences that seek to
understand
• Earth
• Earth's neighbors in space
 Earth science includes
1. geology, the study of Earth
a. Physical geology examines the
materials composing Earth
b. Historical geology is the study of
the origin and development of
Earth
•topics including minerals and
rocks, volcanoes, earthquakes,
faults and folds, soils, erosion,
mountains, plate tectonics, and
geologic history.
1.1 What Is Earth Science?
 Earth science includes
2. oceanography, the study of the
ocean
a. Oceanography integrates
1. Chemistry
2. Physics
3. Geology
4. Biology
We will explore our four major
oceans, the properties of seawater,
ocean floor and coastline features,
ocean sediments, and major ocean
currents.
1.1 What Is Earth Science?
 Earth science includes
3. meteorology, the study of the
atmosphere and the processes
that produce weather
This Includes the study of: clouds
and precipitation types, storms
such as hurricanes and
tornadoes, and fronts, pressure
systems, and weather maps.
1.1 What Is Earth Science?
 Earth science includes
4. astronomy, the study of the
universe
Includes such topics as the sun
and other stars, planets and
other objects in our solar
system, lunar phases, tides,
and eclipses.
Fields of Earth Science
•
•
•
•
•
•
•
•
•
Astronomer
Cartographer
Geologist
Petroleum Geologists
Oceanographer
Meteorologist
Volcanologist
Seismologist
Hydrologists
Formation of Earth
 Most researchers believe that Earth
and the other planets formed at
essentially the same time from the
same primordial material as the
Sun..
 Nebular Hypothesis
• The solar system evolved from an
enormous rotating cloud called the
solar nebula.
Formation of Earth
 Nebular
Hypothesis
• The nebula was composed
mostly of hydrogen and helium.
• About 5 billion years ago, the
nebula began to contract.
• It assumed a flat, disk shape with
the protosun (pre-Sun) at the
center.
Nebular Hypothesis
• Inner planets begin to form from metallic
and rocky clumps.
• Larger outer planets began forming from
fragments with a high percentage of ices.
A
B
C
D
E
Layers Form on Earth
•
As Earth formed, the decay of radioactive
elements and heat from high-velocity impacts
caused the temperature to increase.
• Iron and nickel began to melt and sink toward the
center
•
Lighter rocky components floated outward,
toward the surface.
• Gaseous material escaped from Earth’s interior to
produce the primitive atmosphere.
Earth’s Sphere
• Atmosphere
• Hydrosphere
• Lithosphere
/Geophere
• Biosphere
• Cryosphere
• Anthrosphere
1.2 A View of Earth
1. Hydrosphere
• Ocean is the most prominent feature
of the hydrosphere.
- Is nearly 71% of Earth's surface
- Holds
about 97% of Earth's water
• Also includes fresh water found in streams,
lakes, and glaciers, as well as that found
underground
• A gaseous sphere and it
envelopes the Earth,
• Thin, tenuous blanket of air
• One half lies below 5.6
kilometers (3.5 miles)
• Consists of a mixture of gases
composed primarily of
nitrogen, oxygen, carbon
dioxide, and water vapor.
Atmosphere
http://player.discoveryeducation.com/index.cfm?guidAssetId=0
E074343-4F75-4D95-815B4329F2FD016F&blnFromSearch=1&productcode=US
Biosphere
• All life on earth,
including man, and all
organisms.
• The life zone on our
planet distinguishes
our planet from the
others in the solar
system.
1.2 A View of Earth
4. Geosphere: Lithosphere &
Asthenosphere
• Based on compositional differences, it
consists of the crust, mantle, and core.
- Crust—the thin, rocky outer layer of
Earth.
- Mantle—the 2890-kilometer-thick layer
of Earth located below the crust.
- Core—the innermost layer of Earth,
located beneath the mantle.
2. Divisions of outer portion based on how
materials behave
• a. Lithosphere - rigid outer layer
– 1. Crust
– 2. Uppermost mantle
• b. Divisions of Earth’s surface
– 1. Continents (Continental Crust)
– 2. Ocean Basins (Oceanic Crust)
• C. The asthenosphere is a semi-fluid layer of partly
molten rock located below the Lithosphere
Earth’s Layered Structure
Lithosphere
• The Earth's solid surface,
often called the crust of
the earth. It includes
continental and oceanic
crust as well as the
various layers of the
Earth's interior.
8/1/2012
Unit 1
Cryosphere
• The portion of the
Earth's surface where
water is in a solid
form
• Snow or ice: includes
glaciers, ice shelves,
snow, icebergs, and
arctic climatology
Anthrosphere
• Man and his direct
ancestors, hominids.
• The human
population, it’s
buildings, dams, and
other constructions.
IV. Earth system science
Interconnected Spheres
• Spheres are closely connected
• Changes are often chain reactions
• A change in one sphere results in changes in
others - called an event
– Forest fire destroys plants in an area
• Interactions between spheres
– No plants => erosion
– Soil in water => increased turbidity
– Turbidity => impacts water plants/animals
Event <=> Sphere
• Causes & Effects
• Interactions
• Event <=>Sphere
• Sphere<=>Sphere
ESS Analysis
• Events
– Cause-effect events
– Interactions
– Natural events
• Earthquake, hurricane, forest fires
– Human caused events
• Oil spill, air pollution, construction
Understanding Interactions
• Global implications
• Helps people predict outcomes
• Preparation for natural disasters
• Environmental impacts of human activities
1.4 Earth System Science
 Earth is a dynamic body with
many separate but highly
interacting parts
or spheres.
 Earth system science studies
Earth
as a system that is composed of
numerous parts, or subsystems.
1.4 Earth System Science
 A system is any size group of
interacting parts that form a complex
whole.
 Closed systems are self contained
(e.g., an automobile cooling system).
 Open systems allow both energy and
matter to flow in and out of the
system (e.g., a river system).
Earth Systems
• Although we study four branches of earth
science, there are many interactions between
earth’s systems. You are standing on the
___sphere. You are breathing in part of the
______sphere. If you went to the beach or
canoed down the Chattahoochee River you
where visiting the ______sphere. And you and
all the other living things on earth make up the
_____sphere.
1.4 Earth System Science
 Consists of a nearly endless array of
subsystems or cycles
Cycles Include: Hydrologic Cycle, Rock
Cycle, Geochemical Cycles (carbon,
nitrogen, and phosphorous)
 Humans are part of the Earth system.
All Matter above and beneath the Earth’s
surface moves in cycles.
What drives the earth cycles?
Sun radiates heat down on Earth’s hot core or
the ocean of air and
geothermal energy
water
spreads upward
1.4 Earth System Science
 Sources of Energy
• Sun—drives external processes
such as weather
ocean circulation
erosional processes
• Earth’s interior—drives internal
processes
volcanoes,
earthquakes
mountain building
Magic School Bus Water Cycle
http://www.youtube.com/watch?v=AQKdkponoZM&feature=relate
d
Water cycle constantly transfers the world’s
water between three basic storage reservoirs.
• Oceans contain 97% of Earth’s water
• Of the 3% of the Earth’s freshwater:
– 2.15% is locked away in glaciers and ice sheets
– 0.62% is groundwater, stored as soil moisture
– 0.009% is in rivers and lakes
– 0.001% is in the atmosphere
Fresh water
Amazingly, water in lakes & rivers, water in
rain & snow, water in our bathtub, shower,
and drink bottles, amounts to only about 1%
of the water in the world.
The Water (Hydrologic) Cycle
• Ocean to Atmosphere
– 84% vapor from oceans; 16% from continents
• Atmosphere to Surface
– Vapor cools, condenses & precipitates out in a week, or
few hours or few centuries; depends.
– 77% precipitation falls on the oceans
• Surface to Ocean
– 23% of precipitation in water cycle meets our needs via
“surface water” and “ground water.”
Major steps in the water cycle:
• Ocean to
Atmosphere
• Atmosphere to
Surface
• Surface to Ocean
Water Cycle Animation by NASA
http://www.youtube.com/watch?v=Az2xdNu0ZRk
How do the different types of precipitation
form?
• Rain--Vapor condenses around aerosols and
falls from sky.
How do the different types of precipitation
form?
• Snow—ice crystals that assemble themselves
as they fall through a cloud
How do the different types of precipitation
form?
• Hail--large frozen rain formed in a giant cloud
of an intense thunderstorm.
How do the different types of precipitation
form?
• Sleet--falling snow may partially melt and then
refreeze into a frozen raindrop.
S
U
N
WATER CYCLE
Precipitation
Precip and
Conden
Movement of water
vapor by wind
Evaporation &
Transpiration
Mountains
Run Off
LAKES
Streams
Evaporation
OCEANS
Aquifer
Groundwater
Humans affect the water cycle
• Higher global temperature increased
evaporation.
• Higher ocean temps increase evaporation
• Reduction in rainforest reduces transpiration.
• Reduction of plant life increases runoff
• Glacial melting reduces amount of reflected
light
Geochemical Cycles
Carbon Cycle
• Early atmosphere of Earth 95% CO2. Photosynthetic
plants removed some of the CO2 and added O2.
Today’s atmosphere is 0.04% CO2!
• Reactions of photosynthesis and cellular respiration
Carbon is found in the
couldn’t take place without
carbon. These two
reactions form a atmosphere
continuous primarily
cycle. as CO2
• Two important sources of Carbon are the ocean
(since CO2 dissolves easily in H20) and rocks (such as
coal,
ore and limestone
formed
fromRespiration
dead organisms)
Photosynthesis
:
Cellular
:
Plants taking CO2 out
of the atmosphere and
using it to produce
sugar.
Organisms take that sugar and in
the process of burning energy
release CO2 back into the
atmosphere.
And, another way to look at the carbon cycle:
Humans affect the Carbon Cycle
• Burning of fossil fuels, (oil, coal and natural
gas).
• Fossil fuels were formed very long ago
and is “fixed”: essentially locked out of
the carbon cycle.
• By burning fossil fuels the carbon is
released back into the cycle.
Humans affect the Carbon Cycle
• We presently release more carbon into
the air than can be reabsorbed by
photosynthetic organisms, thereby we
have a net INCREASE of carbon in the
cycle.
• This atmospheric carbon has a role to
play in the warming of the atmosphere.
Geochemical Cycles
•
•
•
•
Nitrogen Cycle
Organisms require Nitrogen to form amino
acids for the building of proteins.
Lots of N2 in our atmosphere
Unfortunately, most organisms CANNOT use
atmospheric nitrogen.
Nitrogen-fixing
Nitrogen-fixing bacteria
CAN usebacteria
N2 fromconvert
the
atmospheric N2 into ammonia
atmosphere.
(NH4) which is a form of
nitrogen that plants CAN use.
Nitrogen Cycle Summary
• Nitrogen makes up 78% of atmosphere as
N2
• Nitrogen-fixing bacteria are very
important - N2 needs to be “fixed” before
it can be used by most living things.
NITROGEN CYCLE
N2
Fertilizer
Production
Lightning
Denitrification
(GAS
)
Crops
Sheep
LegumeFixation
Nitrogen-Fixing
Bacteria in
soil & roots
Decomposers
Ammonia
Nitrates
Nitrites
Nitroge
n
Humans affect the Nitrogen Cycle
• From the production and use of nitrogen
fertilizers to the burning of fossil fuels in
automobiles, power plants, and industries,
humans impact this cycle.
• Excessive nitrogen additions can pollute
ecosystems
Humans affect the Nitrogen Cycle
• Increased global concentrations of nitrous
oxide (N2O), a potent greenhouse gas, in the
atmosphere
• Increased concentrations of nitric oxide, (NO)
that drive the formation of smog along with
N2O
• Losses of soil nutrients such as calcium and
potassium that are essential for long-term soil
fertility
Humans affect the Nitrogen Cycle
• Acidification of soils and of the waters of
streams and lakes
• Greatly increased transport of nitrogen
by rivers into estuaries and coastal
waters where it is a major pollutant.
How do “rocks” “cycle” ?
http://www.youtube.com/watch?v=Jslupi0iW7g
Igneous, Sedimentary, Metamorphic
 Each type of rock records a different
complex past.
 Each type of rock can be changed from one
form to another and back again.
 geologists call these transformations the
“rock cycle”
Rocks
• Igneous = formed by the cooling and
crystallization of magma (melted rock)
• Sedimentary = formed from accumulation
of weathered material (sediments)
• Metamorphic = formed from preexisting
rocks that have been transformed
(changed)
Rock Cycle
http://www.youtube.com/watch?v
=ehcshoYIIM4&feature=related