Download Chapter 17-1

Chapter 17 Notes, part I
Date: _______
17.1: Planet Earth
The Earth--Third Rock from the Sun--is a mostly solid, dense planet comprised of
___ distinct layers:
(1) The _______________, which is the thinnest layer, made
1
of solid rock. Beneath the ocean, called _______________
crust, it is thinner (
___________________ crust (
4
3
2
mi) but more dense than the
mi). Under tall
mountains the _____________________ crust can be as thick
as ____ km or ____ miles.
(2) The ___________ is more dense than the crust and is
nearly _____________ km (__________ mi) thick. It varies from
solid rock at the top to a nearly molten state ( called
diameter = __________
circumference = ___________
“____________”) at the bottom where it is hottest. This layer
is by far the largest, accounting for nearly _____ % of the
Earth’s volume.
(3) The _________ ________ is the ____________ portion of the
Earth’s interior, made mostly of metals such as _______ & ___________.
(4) The _________ _______ is a very dense solid,
The temperature of the Earth __________________ greatly as one travels toward the center.
At the surface the Earth’s average temperature is about _____ °C but in the inner core it is
more than __________ °C. The high interior temperature is thought to be due to high
concentrations of __________________ ___________ in the core undergoing ______________.
The temperature of the mantle, about __________ °C, causes some of the rocks to act like a
very ______________ (“honey-like”) material which allows the crust on top of it to move
around slowly. Through the process of ______________ unequal heating across the Earth
causes some areas of the crust to break and move around on the planet. These pieces,
called ____________ ___________ are seen on the next page. Scientists have noted that many
parts of our planet share unique geological and biological features. It can be easily seen
that the East coast of South America and the West coast of Africa could fit together as
well as the East coast of the US with Northern Africa. A theory, called __________________
________, states that all of the current continents were together at one point in time,
about _____ ________________ years ago. This super-continent, called ______________ broke
apart and the pieces have been on the move ever since. The continental drift theory states
that the Earth’s crust and upper mantle, called the ___________________, are comprised of
seven major pieces (see diagram) moving on top of the lower mantle, called the
_______________________, in a process called ___________ ________________
Tectonic Plates
Without looking back at the front page, draw and label a diagram which shows the layers
of the Earth as close to scale as possible:
Plate Boundaries There are 3 different types of tectonic plate boundaries (places where
plates touch).
(1) ____________________:
Here plates move apart from each other. As the lithosphere parts, molten rock, called
___________, comes up from the ______________________ to fill the gap. As the gap widens
more ___________ fills in. _____________ form at the gap. These _________ are like small
mounds or hills (see diagram)
Divergent Boundary
The biggest and most important divergent plate boundary is the ___________________
__________, which splits the _________________ ocean almost right down its center. It
makes land in _______________ a country known for _________________.
(2) _____________________ boundaries
Here plates move towards each other. There are three types of convergent boundaries:
A.
B.
C.
A. Oceanic-Continental (see diagram)]
Since oceanic crust is thinner and denser than continental crust when the two converge
the oceanic crust goes under the continental crust. As it dives downward, called
_________________, a _____________ forms in the ocean. As the oceanic crust travels under
the continent the continental plate begins to rise and ____________________ form. Further
inland the oceanic crust is so deep that it begins to melt under the tremendous pressure
and magma forms close to the surface. This magma can sometimes push its way to the
surface and produce ___________________. The _______________ Ocean is ringed by
subduction zones and volcanoes--this is why it is called the “_________ ____ _________.”
B. Continental-Continental
Here thick continental plates collided and since they are equal in thickness and density
one does not ride over the other. Instead they both move upwards:
Tall __________________ form at the boundary such as between the Indian-Australian and
Eurasian plates (the ______________________).
C. Oceanic-Oceanic
This is nearly the opposite of the above. Both crusts dive downward:
Deep _________________ form at the boundaries. The ________________ ____________, deeper
than Mt. Everest is tall, forms at the boundary between the Pacific and Philippine Plates.
(3) ______________ __________ Boundaries
These occur when two plates move parallel to each other. The lithosphere appears to
“crack.” These cracks are called _____________. The motion along these boundaries often
gets stuck and energy begins to build up. Eventually this stored energy is released in an
event called an _____________________. One such fault runs through much of California:
the _____ ________________ _________.
Evidence for Plate Tectonics
In the Mid-Atlantic Ridge scientists have discovered “ ________________ ______________.”
This banding shows that every few hundred thousand years the ocean floor rock’s
magnetic alignment “flip-flops” (North and South poles switch). Since the rate of
expansion is reasonably constant (about ________ per year), as is the banding, we know
the Earth’s magnetic field must be switching orientation every so often. Other evidence is
shown in the previously mentioned biological and geological relationships.
Chapter 17 Notes, part II
Date: _______
17.2: Earthquakes
Earthquakes are very common: more than ______________________ occur every year across
the planet (this is about 1 every 10 seconds!). Most are too small to be felt. Around 3000
per year move sections of the Earth’s crust; several hundred more move the crust
significant distances and about 20 create severe changes. ___________________ suffers a
large number of earthquakes (more than nearly any other state) due to the ______
_______________ ____________ and its many offshoots due to the meeting of the
___________________________ and ______________ plates.
An earthquake is a shaking of the Earth caused by the release of stored energy in the
________________________. Large earthquakes near metropolitan areas can produce
widespread damage to buildings, power lines, roadways, bridges, water & sewage pipes and
injure or kill hundreds or thousands of people. If a large earthquake occurs under the
ocean a tremendous uplift of water can be produced. This water can travel at speeds of
______ meters per second (_____ hundred miles per hour) over thousands of miles. When
these waves, called ______________ reach shallower water they slow down, the next waves
catch them and build up. In 2004 one of the most powerful earthquakes ever recorded
caused a wave that traveled throughout the Indian Ocean wiping out many low-lying
villages, killing an estimated 250,000 people. In 2011 a magnitude 9.0 earthquake off the
coast of Japan killed an estimated 20,000 people mostly from the large tsunami. One
person and millions of dollars in damage occured in _____________________!
The release of the energy occurs underground at a point called the __________; this can be
anywhere from _____ miles (shallow) to _____ miles (deep). Generally, the shallower the
earthquake the more damage occurs closer to the quake and the deeper the earthquake
the more the damage is spread out over greater areas. The point on the earth’s surface
directly above the earthquake is called the ________________.
An earthquake produces three types of wave motion:
(1) Back and forth motions that squeezes and stretches rocks are called
_____________________ or _______________ waves (___-waves). These waves can travel
through any medium (even liquids and gases) but travel best through solids at a speed of
about ____ km/sec. The waves look like this:
Remember they are called ____________ waves because they arrive first.
(2) Side to side motions that make particles move at right angles to each other are called
_________ or ________________ (___-waves). These waves only travel through solids since
fluids cannot be “___________.” at a speed of about ____ km/sec. The waves look like this:
(3) When the above two waves finally reach the surface they create a combination of both
waves called ______________ (or ___-waves) that travel slower than either of the waves
individually. Although slower, these waves cause the most damage due to the combination
of up-and-down and and side-to-side motion (_________________) on the surface.
When any large earthquake strikes the entire earth flexes and vibrates like a giant bell.
Devices called ______________________ are used to detect the smallest shaking of the
ground. A ____________________ is drawn showing the
amount of shaking as well as the initial arrival times
of all three waves. The difference in arrival times of
the waves can then be used to determine how far away
the ___________________ is located. Using a method
called ____________________ seismologists use a
minimum of ____ seismographs to determine the
location of the earthquake. An additional
seismograph is needed to determine the __________
which allows seismologists to determine the ________.
Since the p-waves can travel all the way through the
Earth but s-waves cannot seismologists can
determine the makeup of the Earth’s interior. Also,
waves refract as the density changes so don’t travel in
straight lines nor with constant speed (see diagram on next and last pages).
The magnitude and intensity of an earthquake is shown on the ____________ scale for
magnitude (how much energy is released) shown as M#, and the _______________ scale for
intensity (how much shaking felt at a given location) shown in Roman numerals. Each
change of one on the Richter scale (example M3-->M4) is a ____ times increase in energy!
So: (1) How much more energy is released by a M4 earthquake compared to a M2?
(2) Between a M7 and M4?
(3) Between a M9 and a M3?
A list of the World’s deadliest earthquakes:
http://earthquake.usgs.gov/earthquakes/world/most_destructive.php
A list of the US biggest earthquakes:
http://earthquake.usgs.gov/earthquakes/states/10_largest_us.php
A map of recent Bay Area quakes:
http://earthquake.usgs.gov/earthquakes/recenteqsanim/sf/
Magnitude / Intensity Comparison
The following table gives intensities that are typically observed at locations near the
epicenter of earthquakes of different magnitudes.
Magnitude
Typical Maximum Modified Mercalli Intensity
1.0 - 3.0
I
3.0 - 3.9
II - III
4.0 - 4.9
IV - V
5.0 - 5.9
VI - VII
6.0 - 6.9
VII - IX
7.0 and higher
VIII or higher
Abbreviated Modified Mercalli Intensity Scale
I. Not felt except by a very few under especially favorable conditions.
II. Felt only by a few persons at rest, especially on upper floors of buildings.
III. Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many
people do not recognize it as an earthquake. Standing motor cars may rock slightly.
Vibrations similar to the passing of a truck. Duration estimated.
IV. Felt indoors by many, outdoors by few during the day. At night, some awakened.
Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck
striking building. Standing motor cars rocked noticeably.
V. Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable
objects overturned. Pendulum clocks may stop.
VI. Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen
plaster. Damage slight.
VII. Damage negligible in buildings of good design and construction; slight to moderate in
well-built ordinary structures; considerable damage in poorly built or badly designed
structures; some chimneys broken.
VIII. Damage slight in specially designed structures; considerable damage in ordinary
substantial buildings with partial collapse. Damage great in poorly built structures. Fall
of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned.
IX. Damage considerable in specially designed structures; well-designed frame structures
thrown out of plumb. Damage great in substantial buildings, with partial collapse.
Buildings shifted off foundations.
X. Some well-built wooden structures destroyed; most masonry and frame structures
destroyed with foundations. Rails bent.
XI. Few, if any (masonry) structures remain standing. Bridges destroyed. Rails bent
greatly.
XII. Damage total. Lines of sight and level are distorted. Objects thrown into the air.
Chapter 17 Notes, part III
Date: _______
17.2: Volcanoes
Worldwide there are about _______ locations around the world where _________ reaches the
Earth’s surface through cracks in the ____________________. These are called
_________________. The rate at which the magma moves (“flows”) is determined by its
_____________ content (or _______________ ). Magma with high __________ content are
__________, _________-colored and ________ moving. This is called ____________ magma. The
opposite. called __________ magma, is _____________, _________ and flow _______ ___________
due to their lower ___________ content. Once the magma reaches the openings, called
__________, the magma becomes ________. ________ differs from magma slightly because
_________ trapped in the magma escape when it reaches the surface. These ________
include water vapor (
hydrogen sulfide (
), carbon dioxide (
) and sulfur dioxide (
), and sulfur compounds such as
). The amount of dissolved gases will also
determine the type of eruption the volcano might undergo: the more dissolved gases the
______________ the explosive nature of the volcanic eruption.
There are three general types of volcanoes, each one characterized by the type of eruption:
(1) If the magma is _________ the lava flows very easily and far before it cools and hardens.
There is little trapped gas in the magma so the eruptions are usually very ________. The
sides of the volcano are _____________ slopes which can extend for many miles. These are
called ______________ volcanoes which are the _____________ and _______________ in area of
all volcanoes.
(2) If the magma is ___________, the lava flows slower and contains more gas. The
eruptions tend to be an alternating explosion of ____________ & ______ followed by lava
flow. These volcanoes are very ________ with very _______ slopes. Mounts Shasta and St.
Helens are well known _________________ volcanoes.
(3) The third type of volcano, called ___________ _________, are the ______________ but most
________________ (
). These volcanoes contain the most _________ of lava. so
large amounts of gas build up and ______________ eruptions can occur. There is a
tremendous release of ______, ___________ & _______ but little, if any, lava. The cinder and
ash fall back to Earth and form the sides of the volcano. These types of volcanoes usually
lie ____________ for very long periods of time. One of the biggest dangers of these volcanoes
is the __________________ _______, a mixture of __________, ______, ________, and super hot
________________ gas traveling at hundreds of miles per hour down the slopes!
Volcanoes which form underwater are called ________________, which appear much like
composite volcanoes only with ________ tops. Most volcanoes appear at plate boundaries
but sometimes in the middle of a plate it is possible to have a small split (“_______”) in the
lithospheric plate which constantly exposes magma. This magma produces cones. As the
plate moves, the _______ _________ stays in place and a new volcano begins to form.
____________ is the best known hot spot volcano in the world.
Chapter 17 Notes, part IV
Date: _______
17.3: Minerals and Rocks
All rocks are composed of _________________. Most of the common ________________ in the
crust are _____________ (contain _____________ & ______________). In addition to these two
elements, ______________ usually contain one or more additional metallic elements,
usually ________ or ________________. Since ________________ are shaped
as a _________________ there are many patterns and connections among
the various types of minerals such as _________ (layers of minerals);
____________ (long lengths) or even _________ (loops of chains).
By definition minerals are ______________ occurring, ________________
solids (meaning they did not come from living organisms), with a
definite chemical composition and structure (which means you can write a formula for it).
A ______ is a group of minerals bonded together in some way. For example, ____________ is
a rock made of the minerals _____________ and _____________. There nine most common
rock forming minerals are:
Rocks have their own unique set of properties: hardness (ability to scratch another rock);
density; color; porosity (air pockets); and streak (color left behind when dragged on a white
surface). Each of these depends on the minerals which comprise them.
There are three main types of rocks:
(1)_____________. These rocks form by the cooling and hardening of magma or lava.
Depending on whether the ___________ rock forms there are two other identifiers: (a) if the
rock forms on the earth’s surface it will cool rapidly and is called _______________ or
_________________--an example is obsidian or pumice; or (b) if the rock forms below the
earth’s surface it is called _______________ or ________________ (such as granite. Extrusive
rocks lack the grainy texture of intrusive rocks--they appear rather “glassy.” Recall
_____________ rocks will also appear to be darker because they have less silica. _________
rocks will be lighter (more silica) in color. Most plutonic rocks are _________.
(2) ________________: these form when other rocks are exposed to the effects of weather
over many years. Small pieces of rocks are produced due to _________________ and moved
by water, wind or other forces (in a process called _______________) until enough material
can gather and compress or change into ______________________ rock. These rocks are
noted for layers of sediment (sort of a recycling process). These rocks are the only type
which could contain ______________, remains of living creatures or plants. Sedimentary
rocks are identified by the size of the particles which make up the rock, ranging form
pebbles to sand.
(3) _______________________ rocks are formed when heat and/or pressure change one rock
into another. This process can take millions of years and takes place deep in the earth’s
crust. For example: shale exposed to heat and pressure turns into __________.
Lastly, the ________________________ principle states that the older the rock the
_________________ __________ in given depth it is located. In other words, if one drills down
into the ground, the deeper one drills, the older the rock:
The _______ ___________ is the process by which rocks change in the earth. The time can be
from thousands to hundreds of millions of years. Note: the cycle does not have a
particular starting point:
Pumice
_______________________________________________________________________
_______________________________________________________________________
Marble
_______________________________________________________________________
_______________________________________________________________________
Chapter 17 Notes, part V
Date: _______
17.4: Weathering and Erosion
In order for rocks to go through the rock cycle they must be broken down--______________,
and moved--_____________.
Weathering:
(1) ________________ (or mechanical) weathering: rocks are split into smaller pieces of the
same material without changing its composition. There are many ways for this to occur:
(a) ________ _____________: here water collects in small cracks or crevices; when the water
freezes and ice forms it expands causing the cracks to widen; over many repetitions pieces
of the rock break off. This is similar to the cracks which appear in roadways and
sidewalks; (b) ___________ & _____________ on repeated basis will cause rocks like clays to
expand and contract until they break; (c) ___________ ____________: roots often work into
cracks and as they grow the roots further spread the cracks; (d) ______________
_______________ holes in the ground or bringing rocks to the surface; (e) the ________ ____
__________________ _______ (or soil): rocks which are normally below ground are exposed as
other rock or soil above it is removed. The previously hidden rocks begin to move upward
and in the process can break as they move; (f) ____________: sometimes a rock will begin to
tumble down a hillside and in the process it can fracture into smaller pieces and even
break other rocks as it tumbles.
(2) _______________ weathering (new matter forms!)
(a) ________________: some minerals and rocks react with water. Common minerals such as
feldspar and hornblende when exposed to water make ________; (b) reaction with oxygen is
called _________________--this process is very reactive with iron-bearing rocks such as
magnetite and pyrite (“________ ________”); (c) reaction with _______--common _______
include ________________ which naturally occurs when rainwater mixes with CO2 ;
________________, produced when coal and other sulfur-bearing minerals are burned; and
______________, mainly produced when gasoline is burned in the presence of nitrogen.
________________ can be caused by anything which can pick up or push a rock to another
place. The most powerful of all ______________ forces is _______________ ____________, such
as rivers, streams, ocean currents and waves; _______________, although slow can move
large amounts of rocks over great distances; and __________ which can move small rocks
very fast and far. In some parts of the world ________ ____________ are real threats to life
and overall living conditions, especially in _______________.
When eroded material is carried in a river it finally reaches a limit where the river can not
carry it further and the sediment settles. This process, called _________________, often
occurs at the mouth of a river called a ___________, and produces very shallow water. Since
the water continually flows over this shallow spot it slows down so it begins to flow
around the shallow spot and widen. The Bay Area is home to many such ____________:
Topographic Maps
In order to show landforms maps must show the _______________ (the highs and lows) of
Earth’s surface. ___________________ maps show _______________ with ____________ lines.
These lines are drawn to connect points at the same height above (or below) sea level.
For example an island is surveyed and is 3 miles wide by 6 miles long. oval shaped and
more than 100 feet high at its maximum. A simple drawing is shown:
Further surveying will increase the precision of the drawing
and how the land is shaped.
The surveyor marks locations when the elevation changes by
20 feet in this example (marked with x’s). Using this interval
he would continue to survey the island.
Questions:
Y
*
(1) Where is the highest point?
(2) What is the maximum elevation?
Contour interval is 20 ft.
(3) Which side of the island is steepest?
(4) What is the range of elevations at point Y?
When the elevation decreases, such as when you climb into a volcanic crater a
__________________ occurs and a slightly different line is used:
Questions:
(1) What is the contour interval used?
(2) What is the maximum elevation of the volcano?
x
*
(3) What is the minimum elevation inside the crater?
(4) What is the range of elevations at point x?
(1) What is the maximum height on this
B
S
*
island?
Where?
(2) Which is the steepest route:
Y-->A, X-->C, or Z-->B?
(3) What is the minimum depth at B?
Contour interval10
is 10 ft.
(4) What is the range of elevations at point
S?
Chapter 17 Notes, part VI
Date: _______
Biogeochemical Cycles
Elements and/or molecules move through both __________ (“living”) and __________ (“nonliving”) portions of the __________________. The ________________ is the relationship
between all of the inhabitants of a particular region, in this case the region is the entire
Earth. Each element is recycled in varying amounts of time. If a substance stays in one
place for a long time this place is called a ________ or ________________. The opposite, when
a small amount of substance stays for a brief period of time is called a ___________ or
_______________ ________. For example the ocean is considered a ______________ of water
whereas a cloud could be a _____________ of water. All of the chemicals, whether elements
or molecules, nutrients, liquids or gases are part of a ______________ system, so none is
ever lost. ______________ is an _________ system: the _______ gives us energy and that
energy gets lost (actually, it becomes _______________) throughout all of the Earth’s
various systems.
The best known & most important of the Earth’s biogeochemical cycles include:
--the water cycle (covered during the atmosphere unit)
--the oxygen cycle
O 2 is taken in by animals and CO2 is released during ___________________;
CO2 is taken in by plants and O2 is released during _______________________.
(Some carbon dioxide and oxygen is stored in the oceans and underground in rocks.)
--the phosphorus cycle
−3
phosphate ( PO4 ions) are stored in the ground in rocks, in living things as ADP and
ATP and dissolved in water--it is almost never found in the atmosphere. Phosphorus
is a vital element for plants and animals--so important that _____________________
factories
churn out millions of tons of phosphate every year.
€
--the nitrogen cycle (see next page)
nitrogen is the element which makes amino acids and proteins different from
carbohydrates and fats; without nitrogen, life would be far different.
--the carbon cycle (see following page)
as noted before, all __________________ life is based upon carbon--it is a unique
element in chemistry as it forms so many more compounds than any other element.