Midterm Review
Monday October 25, 2010
Announcements
 No warm ups this week
 National Parks Project DUE TOMORROW!!
 Make sure to do your test corrections
 Midterms Wed and Thurs
 Download today’s notes from the class website
Chapter 1
 Earth Science- covers ALL sciences that want
to understand Earth and its neighbors in
space
 Broken down into four major areas
 Meteorology: Study of the processes that produce
weather and climate
 Oceanography: Study of the ocean
 Geology: Study of the physical Earth
 Astronomy: Study of the universe
Chapter 1
 The Earth is divided into four major
spheres
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Hydrosphere: water
Atmosphere: air
Geosphere: physical earth
Biosphere: life (found wherever there is
life, whether that be in the hydro-, atmo-,
and/or geosphere)
Chapter 1
 The Earth is divided into layers
 Crust: thin, rocky outer layer
 Mantle: below the crust, partially liquid,
partially solid
 Upper mantle
 Lower mantle
 Core
 Outer core
 Inner core
Chapter 1
Where does the energy
for the Earth come from?
Sun: external processes
Earth’s interior: internal
processes
Chapter 1
What is a system?
Any group of
interacting parts that
form a complex
whole
Chapter 1
 Mapping
 On the global grid we look at lines of
latitude and lines of longitude to locate
places
 Latitude: “lat lies flat”
 Measures North and South of the Equator (00
latitude)
 Longitude: “runs the LOOOOONG way”
 Measures East and West of the Prime Meridian
(00 longitude)
Chapter 1
 Mapping
 Topographic maps show elevation
 Contour lines- lines that indicate a specific elevation
 Contour interval- the difference in elevation between contour
lines that are next to each other
Chapter 2
 Everything on Earth is made up of atoms
 This is important because the properties of minerals and
rocks depends on the internal arrangement of their
atoms
 Atoms are broken down into 3 subatomic particles
 Protons
 Neutrons
 Electrons
 Atoms have two regions
 Central region = nucleus
 Outer region = electron cloud
Chapter 2
 Important characteristics of elements
 Atomic number: identifies the element
 The same as the number of protons
 Atomic mass: like the “weight” of the
ISOTOPE
 Mass = number of protons + number of
neutrons
 Isotopes of elements have the same #
protons, but different # of neutrons, so they
have different masses.
Chapter 2
 Atoms want to be stable
 To become stable, most atoms will
bond
 The type of bond that forms depends
on the type of the elements
 Metallic: 2 metals
 Ionic: metal and non-metal
 Covalent: 2 non-metals
Chapter 2
 When some atoms bond
together they form
MINERALS!
 Mineral properties depend on
the internal arrangement of
their atoms
Chapter 2
 Mineral Characteristics
 Naturally Occurring
 Solid Substance
 Orderly Crystalline Structure
 Definite Chemical Composition
 Generally considered inorganic
Chapter 2
 Where can minerals form?
 Technically, they can form anywhere
 More often than not, a lot of heat and
pressure is needed to make the
atoms bond together
 High heat and high pressure
would be found in the interior of
Earth
Chapter 2
 Mineral Properties (determined by the internal
arrangement of atoms)
Color- not that reliable
Hardness- measured by Moh’s scale
Cleavage- breaking along flat surfaces
Fracture- jagged breakage
Density- how much “stuff” (mass) in a certain amount
of “space” (volume)
 Streak- color of the powdered form of the mineral
 Luster- how it reflects light
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Chapter 3
 Rocks are solid masses of mineral
or mineral-like matter
 3 groups of rocks
 Based on how they formed
 Sedimentary
 Igneous
 Metamorphic
Chapter 3
 Rock Cycle
Chapter 3
 Rock Cycle
Magma –-- crystallization  Igneous
Rock –-- weathering and erosion 
Sediment –-- compaction and
cementation  Sedimentay Rock
–- heat and pressure  Metamorphic
Rock –-- melting  Magma
Chapter 3
 Review: what are the 2 energy sources for the Earth
system?
 Sun: powers the processes that form sedimentary
rocks
 Earth’s interior: powers the processes that form
igneous and metamorphic rocks
Mid-term Essays
 Your mid-term will include two essay questions
 I will not tell you EXACTLY what the essays will be,
but they will be chosen from the questions we go
over today and tomorrow
 You will take the essay portion of the test on WED.
 To prepare, you will outline key points for the
essays in a google doc (or a sheet of paper) to
organize your thoughts.
Midterm Essays
 For the following two questions write down at least 7 key
points for the question.
1. Why do atoms bond to form minerals? What
are the five characteristics that make something
a mineral? Describe two different mineral
properties.
2. Describe the path a rock takes from magma 
igneous rock  metamorphic rock 
sedimentary rock  magma. Describe where
the energy for the formation of the three rock
types comes from.
Study Guide work-time
 For the rest of class time, you should work on your
study guides.
 Questions # 1- 25 should be done before class
tomorrow for you to be on-track for an A+
 If you are finish your questions early, it’d be a great
idea to not only have the key points for your
potential essays, but also write a rough draft (trust
me, this is NOT a waste of your time)
MIDTERM REVIEW –
Day 2
PLATE TECTONICS
Plate Tectonics
 THINK ABOUT IT: How
would our earth be different if
there were no plate tectonic
movement?
Announcements
 National Parks Projects are DUE TODAY!!
 Reminder: no late projects will be accepted without
a call or email from a parent.
 MIDTERMS begin tomorrow!
Theories of Plate Tectonics
 Before the theory of plate tectonics was the
theory of continental drift – a theory stating that
the continents were once joined to form a single
supercontinent
 Alfred Wegner provided four evidences to support
that earth’s continents formed Pangaea:
1. Continental puzzle
2. Fossil evidences
3. Ancient climates (glaciers were once where?)
4. Rock Types
Theories of Plate Tectonics
 The theory of Continental Drift was
rejected because:
 Wegner could only come up with
ILLOGICAL explanations for the
movement of the continents.
Plate Tectonics
 The theory of Plate tectonics the earth’s
crust (lithosphere) is divided into
several plates that move around the
planet. When the plates interact they
form a boundary:
 Convergent
 Divergent
 Transform fault
Plate Tectonics
 Key evidence that supports the Theory
of plate tectonics:
 Seafloor spreading
 Paleomagnetism
Mountain Building
 Plate movement creates STRESS on rocks,
making them DEFORM.
Types of Stress:
1.Compressional
2.Tensional
3.Shear
Types of Deformation:
1. Elastic
2. Brittle
3. Ductile
Mountain Building
 OROGENISIS – general term for the
process that produces mountains.
 Mountains are classified by the dominant
processes that form them.
 Types of Mountains:
1. Folded
2. Fault Block
3. Domes and Basins
4. Volcanic
Mountain Building
 Mountains are mainly formed by plate
boundaries.
 Convergent: oceanic-oceanic, oceaniccontinental
 An example of this is an accretionary
wedge.
 An accretionary wedge is an accumulation
of different sedimentary and metamorphic
rocks combined with scraps of ocean crust.
Mountain Building
 Isostatic Adjustment
 When the earth’s crust adjusts to support
the weight of a mountain.
 This process is controlled by gravity.
Essay Preparation – Plate
Tectonics
 On the class website, or on a separate piece of paper,
answer the following question in preparation for the
essay portion of the midterm tomorrow. Include at least
7 sentences.
1. Describe the actions that occur at
each of the three plate boundaries.
Include what happens to the earth at
each boundary and a geographic
example of at least 2 of them.
Earthquakes
 Earthquakes are caused by plate
motion.
 Different ways radiate from the
FOCUS of the earthquake causing
destruction:
 P waves: fastest
 S waves: second fastest
 Surface waves: slowest and most
destructive
 At 1500 miles, how
many minutes does
the s-wave arrive
AFTER the pwave?
 _______________
 When will the first
p-wave be received
if it is 2000 miles
from the epicenter?
 ________________
Earthquakes
 Where would you be safest during an
earthquake?
 In an area with granite bedrock
 What is a tsunami?
 A succession of ocean waves set in motion by a
submarine earthquake.
Volcanoes
 A volcano is a type of mountain formed
from magma escaping from earth’s crust.
 Magma tends to rise towards Earth’s
surface primarily because rocks become
LESS DENSE when they melt.
 The form of the volcano is determined by
the composition of the magma.
Volcanoes
 Magma is formed by melted rock – the
three factors that affect the melting
point of a rock are:
1. Composition of the rock (material)
2. Water content
3. Confining pressure (less confining
pressure = easier to melt)
Volcanoes
 Three things come out of a volcano:
1. lava – aa flow and pahoehoe flow
2. pyroclastic material - the particles
produced in volcanic eruptions
3. gases
Volcanoes – not in notes
 A volcano is highly explosive if the lava
escaping from it is high in VISCOCITY.
 Viscocity – resistance to flow
 Silica content affects lava viscocity directly –
the higher silica content, the higher viscocity.
 Gas content also affects lava viscocity directly
– the higher gas content, the higher viscocity.
 Temperature affects lava viscocity REVERSLY
– the higher the temperature, the lower the
viscocity.
Essay Preparation–Plate
Tectonics
 On the class website, or on a separate piece of
paper, answer the following question in
preparation for the essay portion of the midterm
tomorrow. Include at least 5 sentences.
1. Describe how silica content, temperature
and gas content affect the viscocity of
magma. How does magma with high
viscocity affect the explosion of an
earthquake? Why does magma rise to
the surface of the planet?
Midterm Study Guide
 Use your book and notes to work on
your study guides for Plate Tectonics
(starting on number 26).
 Remember, test starts TOMORROW
(essays!)
 Study guides are due THURSDAY
Midterm Review – Day 3
Geologic Time
Warm Up – Review Essay
Questions
1. Why do atoms bond to form minerals? What
are the five characteristics that make
something a mineral? Describe two different
mineral properties.
2. Describe the path a rock takes from magma
 igneous rock  metamorphic rock 
sedimentary rock  magma. Describe where
the energy for the formation of the three rock
types comes from.
Warm Up – Review Essay
Questions
3. Describe how silica content, temperature
and gas content affect the viscocity of
magma. How does magma with high
viscocity affect the explosion of an
earthquake? Why does magma rise to the
surface of the planet?
4. Describe the actions that occur at each of the
three plate boundaries. Include what
happens to the earth at each boundary and
a geographic example of at least 2 of them.
Announcements
 National Parks Project is OVERDUE –
turn it in with a note/email/call from
a parent.
 Midterms start TODAY!
 Study Guides are due when you walk
in the door tomorrow!
Geologic Time
 Our planet has existed and changed for
billions of years!
 The physical, chemical, and biological
laws that operate today have also
operated in the geologic past – this is
part of the principle of
UNIFORMITARIANISM.
Geologic Time
 Scientists have been trying to interpret earth’s
history for hundreds of years.
 Scientists interpret earth’s history through
RELATIVE DATING - dating process that
places geologic events in proper sequence.
 Law of superposition
 Principle of original horizontality
 Fossils are evidences of past life.
 A quick burial and hard parts of an organism
are important in making fossils.
Geologic Time
 Absolute dating is using radiometric
dating to find the EXACT age of a rock
or fossil.
 A half life is the time it takes for 50% of
the nuclei in a radioactive sample to
decay to its stable isotope.
 What fraction of
the original
parent isotope
still exists after 3
half-lives have
passed?
______________
 If 1/16 of the
parent material is
left, how many
half lives have
passed?
____________
Geologic Time Scale
 The Geologic Time Scale covers 4.56
billion years – the length of the history
of the planet.
 The scale is broken into Eras that cover
massive amounts of time:
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Precambrian: life was confined to the seas
Paleozoic: Era of “ancient life”
Mesozoic: Age of the Reptiles
Cenozoic: Age of the Mammals
Everything
else
Precambrian
Geologic Time Scale
 Originally, the Earth’s atmosphere had no
free oxygen.
 The major source of the free oxygen in our
atmosphere is green plants through
photosynthesis .
 Animals evolved:
 First they lived only in water
 Amphibians – lived in water, but could visit
land
 Reptiles – the first true terrestrial animals.
Cold blood.
 Mammals – warm blood
Midterms – Essay
Questions
 Clear everything off your desks except
something to write with.
 When you finish, you may continue to
work on your Study Guides.
 No computers will be allowed on
desks for the remainder of the class.