Transcript Earth`s Physical Systems: Matter, Energy and Geology.

Earth’s Physical Systems:
Matter, Energy and
Geology.
Anna Kajzer
www.science.kennesaw.edu/~jhendrix
What is matter?
 All material in the universe that has mass
and occupies space
 The amount of matter stays constant as it
is recycled (law of conservation of
matter), it can’t be created or destroyed
 It is composed of organic and inorganic
compounds
Is the law of conservation of matter
important in the environment?
 Yes, pollution and waste will not simply
disappear when we dispose them!
 Plastics (synthetic polymers), such as
polyethylene, polypropylene, polyurethane, and
polystyrene are manufactured products that
are long – lasting and resist chemical
breakdown, BUT they are serious source of
waste and pollution, which endangers wildlife
and human health for a long time.
What are polymers?
 Chemical compounds or mixture of
compounds consisting of long chains of
repeated molecules
 Some polymers play key roles in the
building blocks of life
What are the building blocks
of life?
 Some polymers, such as proteins, nucleic
acids, carbohydrates (starch, chitin, cellulose),
lipids, fats, oils, and waxes.
 They are organic compounds having carbon
atom/s and other elements.
 Scientists use the concept of the building
blocks (macromolecules) to produce synthetic
polymers.
Are only synthetic polymers
cause concern in the
environment?
 No!!! Nucleic acids present in DNA and RNA
(organic macromolecules) that carry hereditary
information for organisms.
 Regions of DNA called genes that code for
specific functions get manipulated in the gene
engineering to produce mutant organisms
(genetic engineering).
 Consequences are unknown, eg. Cultivated
plants may become weeds (unwanted plants),
Which of the organic
compounds are important in
the environment?
 Hydrocarbons containing carbon and
hydrogen
 Some hydrocarbons, such as the
polycyclic aromatic hydrocarbons, PAHs,
are found in gasoline and oil as well as in
combustion products and are known to
be toxic to wildlife and humans.
What are the other
compounds that cause
concern?
 (compounds are made of two or more different
elements)
 Carbon dioxide consisting of one carbon atom
and two oxygen atoms
 CO2 - a colorless gas used by plants for
photosynthesis, given off by respiration, and
released by burning fossil fuels.
 A primary greenhouse gas whose buildup
contributes to global climate change
(greenhouse effect)
Is ozone a compound?
 No, O3 (ozone) is a molecule.
 A molecule is formed when atoms bond
together, such as oxygen or ozone
 Ozone absorbs UV radiation in the
stratosphere.
What is ozone hole?
 It is thinning of the stratospheric ozone layer (
10-19 mi above sea level) that occurs over
Antarctica each year, as a result of
chlorofluorocarbons (halocarbons)
 Halocarbons are human made chemical
compounds derived from simple hydrocarbons
in which hydrogen atoms are replaced by
halogen atoms such as bromine, fluorine, or
chlorine.
What are atoms?
 The smallest units maintaining chemical
properties of the element.
 Atom has a nucleus in which there are
positively charged protons (atomic number)
and neutrons having no charge (sum is called
the mass number) and electrons negatively
charged particles surrounding a nucleus.
 The number of protons, neutrons, and
electrons is usually the same. Na (sodium has
11 protons,11 neutrons and 11 electrons)
If the number of protons and
neutrons is different do the
atoms behave the same?
 No, they have the same chemical properties, but
different physical properties. They are called
ISOTOPES.
 Some isotopes may be radioactive, such as Uranium 235, our source for nuclear power.
 Radioactive isotopes change their chemical identity as
they shed atomic particles and emit high energy
radiation, it “decays” till it becomes a stable isotope.
 For Uranium half-life (the amount of time it takes for
half of the radioactive isotope to decay) is 700 million
years (danger of explosion of nuclear power, eg,
Tsunami in Japan and explosion of nuclear reactors)
How do elements, molecules
and compounds come
together?
 With chemical bonding or
 Without chemical bonding.
What is chemical bonding?
 Attraction for electrons
 Electrons may be shared
 eg H – H molecular bonding
O=O (non-metals)
H \
O hydrogen bonding in water
H /
 Electrons may be transferred
(metal + non-metal)
Na – e = Na + (ion)
Cl + e = Cl - (ion)
Sodium donated one electron to chlorine
This is called ionic bonding forming salts
NaCl is an ionic compound
How do elements molecules
and compounds come
together without chemical
bonding?
 They mix together and form mixtures
 Mixtures can be heterogenous
(muddy water) or
homogenous = solutions (salty water)
What are the properties of
water?

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Universal solvent
Is cohesive
Has high heat absorption capacity
It may occur in one of the three phases: gas,
liquid or solid
 A solid form is less dense than the liquid form
 It has an ability to dissolve or hold in solution
many other molecules
What is acidity?
 Hydrogen ions determine acidity
 Solutions in which H+ concentration are greater
than OH- are acidic.
 The reverse case is basic or alkaline.
 The pH (potency of hydrogen) scale quantifies
acidity or alkalinity.
 pH less than 7 indicates acidity (lime juice), pH
greater than 7 indicates alkalinity (soap), pH 7
is neutral (pure water)
What is acid rain?
 Acid deposition (settling of acidic or acid
forming pollutants from the atmosphere
onto Earth’s surface.
 Presence of hydrogen ions determines
acidity of this aqueous solution (acid rain)
What is energy?
 It is capacity to change the position, physical
composition or temperature of matter.
 It is force that can accomplish work
 Energy is always conserved but it may change
form to another (when water surges to the
surface, the kinetic energy of its movement will
equal the potential energy it held
underground)= First Law of Thermodynamics
 Energy tends to change from more-ordered state
to a less – ordered state. Second Law of
Thermodynamics.
 Systems tend to move toward increasing disorder
(entropy).
 The order of an object or system can be increased
through the input of additional energy from outside
the system.
 In every transfer of energy, some portion escapes.
The degree to which we successfully capture
energy is called Energy Conversion Efficiency
(ratio of useful output of energy to the amount that
needs to be input).
Where does energy come from?
(in living organisms)
 There are different sources of energy.
 Light energy from the sun is used by the plants
(autotrophs = primary producers) in the
process of photosynthesis to produce food.
NB. Pollution, volcanic ashes inhibit passage of
radiation.
 Chemical energy from hydrogen sulfide is used
by deep ocean organisms to produce their own
food (chemosynthesis).
How is photosynthesis and
respiration related?
 They are complementary processes.
 Animals (heterotrophs = consumers) depend
on the sugars and oxygen from
photosynthesis.
 In cellular respiration chemical energy is
released (cells employ oxygen to convert
glucose back into its original starting material
i.e., carbon dioxide and water, and energy is
released.
Why is chemical energy
important?
 Chemical energy is a special type of
potential energy that may be changed
into kinetic energy = energy of motion
(walking, exercising, doing work).
Does Earth have or need
energy? (non-living things).
 Yes, ocean tides are caused by the
gravitational pull (energy) of the moon in
conjunction with the sun)
 Geothermal heating emanating from the
inside the earth is powered by radiation
from the radioisotopes deep inside our
Earth.
What is geology?
 The study of Earth’s physical features,
processes and history.
What are the physical features
of Earth?
 Structure, Earth consists of layers
1. A dense core at the center consisting of iron,
solid in the inner core and molten in the outer
core.
2. Mantle, (less dense than the core) elastic
layer, having a layer called asthenosphere,
soft rock and a layer called lithosphere
including
3. Crust = the thin layer of rock that covers the
surface of Earth.
Does Earth have constant
temperature?
 No, the heat from inner Earth rises to the
surface and dissipates.
 Within a few miles of the surface
(asthenosphere) we can drill ot tap geothermal
energy.
 The soil and rock just below the surface has
fairly constant temperature (cooler than the air
in summer and warmer than the air in winter); it
allows to use geothermal energy for heating of
the houses in more efficient way.
Does the heat from the inner of
Earth have any influence on the
crust?
 Yes, it drives convection currents that
move mantle material. This material
moves and drags lithospheric plates
along the surface = plate tectonics.
Does plate tectonics shape
Earth’s geography?
 Yes, Earth consists of about 15 major
tectonic plates which move about 2 to 15
cm per year.
 This movement influences Earth’s
climate and life’s evolution.
How many types of plates
boundaries are there?
 Three
1. New crust may be created (at divergent
plate boundaries, tectonic plates push apart
as magma rises upward to the surface,
creating new crust, eg. Mid-Atlantic ridge)
2. Where two plates meet, they may slip and
grind alongside one another, forming a
transform plate boundary = a fault eg. San
Andreas Fault in California.
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Plates may collide at convergent plate
boundaries and
1. Subduction may occur (one plate slide
beneath the other) causing volcanic
eruptions eg. The Cascades in the Pacific
Northwest led to the eruption of Mt. Saint
Helens in 1980 and 2004
2. Continental collision where the continental
plates meet and both sides resist subduction,
they crush together, bending and deforming
layers of rock, eg. The Himalayas were
formed in this manner.
What do tectonics do on Earth?
 Produce Earth’s landforms, eg. The
Geysers in California located above a
region of subduction (magma rises to the
surface.
 Shape climate and life’s evolution b/c
changes areas of coastal regions to
continental and vice versa.
What is rock cycle?
 It is one of the geological processes (the other
one is plate tectonics).
 Rocks are heated, melted, cooled, broken
down and reassembled in a very slow process
over geological time.
 Rock is a solid aggregation of minerals (solid
element of inorganic compound with a crystal
structure, a specific chemical composition and
distinct physical properties).
What are the types of rocks?

Igneous - formed when lava (magma on the
surface of Earth) cools across Earth’s surface
1. Intrusive - when magma cools slowly and
solidifies below Earth’s surface (large crystals
such as granite)
2. Extrusive – when molten rock is ejected from
a volcano and cools quickly (eg. Basalt).
Sedimentary rock – when sediments are
physically pressed together; dissolved
minerals bind the particles together in a
process called lithification, eg. Sandstone,
shale and limestone.
1. Sediments (particles of rock blown by wind
or washed away by water in physical
processes or precipitation of substances
our of solution form chemically).
2. These processes create the fossil fuels
and fossils of organisms.
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 Metamorphic rock – any type of rock is
subjected to great heat or pressure, eg.
slate and marble.
What are the geologic and
natural hazards?
1. Earthquakes and volcanoes (Earth’s
geothermal heating gives rise to
creative forces that shape our planet).
 Nine out of ten of the world’s
earthquakes and over half of the world’s
volcanoes occur on plate boundaries on
the circum-Pacific belt, called “ring of
fire”.
What causes earthquakes?
 Movement at plate boundaries and faults.
Plate boundaries and places where faults occur
may relieve built-up pressure and release of
energy called earthquakes.
Damage from earthquakes is generally greatest
where soils are loose or saturated with water.
Engineers developed ways to protect buildings
and there are new building codes n
earthquake-prone areas such as California and
Japan.
What is the origin of volcanoes?
 They arise from rifts, subduction zones or
hotspots.
 Where molten rock, hot gas, or ash erupt
through Earth’s surface, a volcano is
formed, often creating a mountain, eg. Mt
Kilauea in Hawaii (lava flows
continuously downhill) or Mt. Saint Helen
(sudden eruption in 1980).
What type of environmental
impact can volcanoes cause?
 Depress temperature throughout the
world as a result of ash blocking sunlight
 Sulfuric acid hazes that block radiation
and cool the atmosphere.
What is mass wasting?
 Downslope movement of soil and rock
due to gravity when a landslide occur.
 It can be brought about by human land
practices that expose or loosen soil.
 May occur following volcanic eruptions or
torrential hurricane rainfall.
 Can be colossal and deadly.
What are tsunamis?
 An immense swell or wave of water that can
travel thousands of miles across oceans.
 They may be caused by earthquakes, volcanic
eruptions, and large coastal landslides.
 Residents of the USA are vulnerable to
tsunamis. A Canary Island volcano could put
Atlantic –coast cities at risk.
What are the natural hazards?
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Flooding
Coastal erosion
Wildfire
Tornadoes
Hurricanes
Could we mitigate the impacts
of natural hazards/
 We can reduce the impacts of hazards
through the thoughtful use of technology
and a solid understanding of geology
and ecology.
Could we worsen the impacts of
natural hazards?
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1.
2.
3.
4.
5.
Yes
More people live in areas susceptible to disaster b/c
of the population growth or b/c of our choices.
We use and engineer landscapes in wasy that can
increase the landslide, flooding, erosion.
We change Earth’s climate by emitting greenhouse
gases.
We alter patterns of precipitation, increasing risks of
drought, flooding and fire.
Rising sea levels increase coastal erosion.
CONCLUSION
 Comprehending matter (chemistry) and energy
(physics) is essential for environmental science
to find solutions.
 geology and its physical processes are
important because they shape Earth’s surface
and generate phenomena that can threaten our
lives and property.
 Geothermal heating provides one way into the
broad phenomena of chemical and physical
processes that shape Earth.
For further research
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http://response.restoration.noaa,gov/bat.about.html
http://antoine.frostburg.edu/chem/sense/101/index.shtml
http://nssdc.gsfc.nasa.gov/planetary.marslife.html
www.pmel.noaa.gov/vents
http://www.eoearth.org/
http://earthquake.usgs.gov/earthquakes/recenteqsww/
http://shopping.dicovry.com
http://gallery.usgs.gov/video_collections/Natural_Hazards
http://earthobservatory.nasa.gov/NaturalHazards,category.php?ca
t_id=9
 http://map.ngdc.noaa.gov/website/seg/hazards/viewer.htm