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GLOSSARY OF TERMS
Abiotic factors
Abiotic factors - Nonoliving factors
that affect the ecosystem: light, space,
temperature, shelter, water, and soil
composition
Acceleration - Change of an object's
speed or direction
Action - Force exerted on another object
Adaptation - A process by which a
population becomes better suited to
its habitat; a genetic variation of an
individual in a population that provides
Axis
Asthenosphere - The soft upper layer
of the mantle just below the lithosphere.
The asthenosphere is solid, yet soft '
enough to flow. This property is called
plasticity. The tectonic plates move on the
asthenosphere
Atmospheric movement - Global air
circulation patterns within the atmosphere
held to Earth by gravity and warmed
as heat radiates from Earth; influenced
by convection of cold dense air to sink,
causing warm less dense air to rise and
spread out
an advantage to survive and reproduce,
generally spreads through the population
Air masses - A body of air extending
over a large area (1,000 miles or more)
that develops and retains specific
characteristics of pressure, temperature,
and humidity
Air pressure - The force exerted by the
atmosphere on Earth's surface by the
weight of the air above the surface
Anemometer - A scientific tool used to
measure wind speed
Aquatic ecosystem -An ecosystem that
is located in a body of water
At rest - The state of an object when it is
not in motion
Atmosphere - The whole mass of air
surrounding the Earth made up of 78%
nitrogen, 21% oxygen, and other trace
gases
Atom - The smallest unit of an element
that has all of the properties of that
element containing a nucleus of protons
and neutrons within an electron cloud
Atomic number - The number of protons
in the nucleus of one atom of an element
Autotroph -An organism that produces
its own food such as a plant; producer
Artificial reefs - A man-made,
underwater structure, like a sunken ship
or an oil rig, that promotes marine life
Average atomic mass- The average
mass of protons and neutrons in an
element
Axis -The imaginary line extending from
the North Pole to the South Pole going
through the center of Earth, which is the
center of Earth's rotation
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GLOSSARY OF T£R@S
Balanced chemicaÿ equation
Condensation
BaJanced chemicaÿ equation -A
symbolic representation of a chemical
reaction in which both sides of the
equation contain equivalent numbers of
atoms of each element. The mass and
the charge must be balanced on both
sides of the reaction
Balanced forces - Forces of an object
that do not change the motion of the
object
Barometer - An instrument that.
measures the amount of atmospheric
pressure
Big Bang Theory -A theory that
explains the evidence observed in 1929
by Edwin Hubble that galaxies outside
our own Milky Way were all moving away
from us, each at a speed proportional to
its distance from us; this led to the theory
that the universe expansion began as a
small point that expanded rapidly about
13.7 billion years ago
Biotic factors - Living factors affect the
ecosystem: organisms such as bacteria,
fungi, plants and animals that affect a
population within the ecosÿ/stem
Bÿack hoÿe -An object with the mass of
more than four suns squeezed into a ball
only 10 km in diameter whose gravity is
so strong that even light cannot escape
Bÿue shift -An apparent shortening of
the wavelength of light toward the shorter
(blue) end of the visible light spectrum as
the distance between the source and the
observer decreases. It is not a shift in the
actual frequency from the source
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Carnivore -An organism that consumes
other animals
ChemicaH equation - Chemical formulas
and symbols written to represent a reaction
Chemical formula - A shorthand
notation that uses chemical symbols and
numbers as subscripts to represent the
type and number of atoms present in the
smallest unit of the substance
Chemical reaction -The process by
which one or more substances change
to produce one or more different
substances; also called a chemical
change
Chemical symboJ- A one or two letter
notation used to represent an atom of a
particular element; sometimes referred to
as an atomic symbol
Climate change - Changes in the
average temperature, precipitation, and
other weather conditions in an area
Coefficient -A number placed in front of
a chemical symbol or formula in order to
balance the equation
CoUd front - The leading edge of a cold,
dry air mass that overtakes a warmer,
humid air ma'ss
Competition - Ecological relationship
where more than one individual or
population in an ecosystem relies upon
the same limited resources
Condensation - The change from gas
state to liquid state
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GLOSSARY OF TERMS
ConsuR/eF
Consumer-An organism that must
consume other organisms for nutrients
Continentam drift - The theory that
continents were once connected, but
have drifted apart
Dust lanes
Cosmic Microwave Background (CMB)
- Electromagnetic radiation that fills the
universe, detected with a radio telescope;
this is explained as being left over from
early development of the universe that
fills the universe and is offered as key
proof of the Big Bang theory or the origin
Contour interval- The difference in
elevation between two adjacent contour
lines of a topographic map
Contour line -A line on a topographic
map that connects points with the same
elevation
Convection - Transfer of thermal energy
through circulating motion caused by
heating and cooling in fluids (liquids and
gases), causing convection currents
Convection currents-A cyclical motion
occurs because of density differences
in a fluid. In the mantle of the Earth
heated, less dense lower regions of the
fluid mantle rise, and denser, cooler
regions sink due to gravity. The combined
motions serve as the engine for crustal
of the universe
Crescent moon - Shape or phase of the
Moon that is less than a quarter moon
Decomposer- Organisms such as
bacteria and fungi that break down the
remains of dead plants and animals,
without need for internal digestion
Directlindirect- Direct: In the shortest
unbroken line. Indirect: Angled or spread
out temperatures are higher where the
Sun's rays are direct and lower where the
Sun's rays are indirect
Direct vs. indirect sunlight = Direct
sunlight results in temperatures that are
higher than where the Sun's rays are
indirect
movement
Convergent boundary-'In plate
Direction - The path that an object is
moving or facing
tectonics, the boundary between two
tectonic plates moving toward each
other; results in mountain - building
when continental plates of equal density
converge, or volcanic activity when a
Divergent boundary - The boundary
between two tectonic plates moving away
from each other; on land it creates rift
valleys, on the sea floor it creates new
denser ocean plate subducts, or moves
ocean crust and mountainous ridges e.g.
below a continental plate or another
oceanic plate
Mid-Atlantic ridge
Coriogis Effect - The apparent deflection
Dust lanes - Bands of dust that appear
as dark ribbons against the bright stars in
a galaxy
of moving air, as see by an observer on
Earth as a result of Earth's rotation
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GLOSSARY OF TERMS
Extinct
Ecosystem
Ecosystem - A system consisting of all
of the interactions that occur between
the abiotic and biotic factors within an
environment
Electrical charge - A form of charge,
designated negative, positive, or neutral
(without charge) that is found on the
ElÿipticaHoshaped galaxy -A galaxy with
a long oval shape, a bright center, no
apparent internal structure or spiral arms,
and very little dust or gas
Endothermic-A reaction that gets cold
because heat energy is absorbed from
the surrounding area
subatomic particles that make up all
atoms
Electromagnetic radiation -The type
of energy released by stars consisting of
electric and magnetic waves that travel at
Energy leveg -A specific region around
the nucleus where electrons having the
same amount of energy may be found
the speed of light
Energy pyramM -A diagram that shows
the energy contained in various trophic
levels of organisms in a food web
Electromagnetic spectrum - A
grouping of all possible energy levels
of electromagnetic radiation from radio
waves to gamma radiation and includes
Erosion - The process by which water,
ice, wind, and gravity remove and
visible light
transport sediments from one place to
another
Electron, eo - A negatively - charged
Erosiona! feature - Evidence on Earth's
subatomic particle of the electron cloud
that is involved in the formation of
chemical bonds
surface that shows the natural processes
of weathering and the removal and
relocation of weathered materials
Electron cJoud -All of the area inside
an atom surrounding the nucleus where
Evidence of a chemical reaction - four
observable signs of a chemical reaction
electrons are found
are: production of (1) gas, (2) heat/light,
formation of (3) precipitate or a (4) color
Electron sheig - A specific area where
electrons of the same energy level are
found
change
Eÿement -A pure substance that cannot
be separated into simpler substances by
physical or chemical means
Exothermic - A reaction that gets
hot as heat energy is released to the
surrounding area
Extinct- When living members of a
species no longer exists
Elevation - Indicates the height to which
something is relative to sea level
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GLOSSARY OF TER@8
First quarter moon
First quarter moon - Half the disk of the
Moon is illuminated and the cycle is in the
waxing phase
Food chain -The path of food energy
from the Sun, to the producer, then
High tide
Gamma rays - Electromagnetic waves
with the highest energy and very short
wavelengths; produced by supernovas,
the destruction of atoms, or the decay of
radioactive material
transferred to a series of consumers
Gibbous moon - Shape or phase of the
Moon that is greater than a quarter moon,
Food web - Overlapping food chains
but not full
with different pathways for the flow of
food energy in an ecosystem
Force -A push or pull that can change
the motion of an object
Gravitationan puin - The attraction
between two objects due to the invisible
force of gravity; the gravitational pull from
the Moon is primarily responsible for the
tides that form on Earth
Fossi0 - Preserved remains, or a mold/
impression of an organism left in rock
layers that indicates the organism once
lived in an area
Groups (of elements) - The columns
on a Periodic Table that arranges the
elements by the number of electrons
which are in the outside shell or orbital
Frame of reference -A system that uses
coordinates or background objects to
establish position or measure movement
of a point in space
Hemisphere - Half of the terrestrial
globe or celestial sphere, can be divided
by north and south or east and west
Freshwater ecosystem - An ecosystem
found in streams, lakes, and rivers where
only plants
Herbivore -An organism that consumes
the water has less than 1% salt content
Friction -A force between two surfaces
rubbing against each other; friction works
against motion
Hertzsprung°Russe]ÿ Diagram - A plot
of the surface temperature (color) of stars
vs. their luminosity (brightness)
FuRl moon - Entire disk of the Moon
Heterotroph -An organism that must
use other organisms for food such as
illuminated
animals; consumer
Galactic center - Rotational center of
High tide - When the tide is at its
a huge galaxy such as the Milky Way
greatest elevation
Galaxy
Galaxy. A large grouping of stars in
space
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GLOSSARY OF TER S
High-pressure air mass
Longoterm envJronmentaÿ charÿge
High-pressure air mass -An air mass
with greater atmospheric pressure than
the surrounding air masses; air moves
away from the high pressure, traveling
in a clockwise direction in the Northern
hemisphere
Uon - Charged atom or molecules that
forms as a result of the loss or gain of
electrons; identified by the overall net
charge
irregular-shaped galaxy - A galaxy that
does not fit into any category; a galaxy
Host -An organism that is harmed by a
parasite that live in or on it
with very little symmetry
Humidity - Amount of water vapor or
moisture content in the air
Last quarter moon - Half of the disk of
the Moon is illuminated and the cycle is in
the waning phase
Hurricane - A large, tropical weather
system consisting of an extreme low
pressure air mass with heavy rains and
wind speeds of at least 119 km/h
(74 miles/hr)
Law of Conservation of Mass - The
mass of all reactants must equal the
mass of all products; matter is neither
created nor destroyed
for measuring the humidity of the
atmosphere
Lenticuÿaroshaped gaJaxy - Galaxy with
a central bulge or bar with short arms,
if any are present; lenticular refers to a
"lens-like" shape like a biconvex lens
Index contour- A thicker line marking
every 5th contour line of a topographic
map
Light waves - Part of the
electromagnetic spectrum that provides
us with visible light spectrum, the colors
Hygrometer - any of several instruments
we see
Inertia - The tendency of a physical
object to remain still or continue moving,
unless force is applied
Light year -A unit of length equal to the
distance that light travels through space
in one year
hfrared waves - Electromagnetic waves
with longer wavelengths than visible light,
but shorter than radio waves
layer of Earth that is divided into
Invasive species -Alien (not native to
the ecosystem) species brought to an
enormous pieces called tectonic plates;
consists of the crust and the rigid
uppermost part of the mantle
Lithosphere- Cool, rigid, outermost
area, that competes for resources and
cause problems for the native species
within an ecosystem
Long-term environmenta0 change-
Environmental change that occurs slowly
over time and affects organisms over
generations
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GLOSSARY OF TERMS
Low tide
Low tide - When the tide level is at its
lowest elevation
Low-pressure air mass -An air mass
with less atmospheric pressure than
the surrounding air masses; air moves
toward the low pressure, traveling in
a counter-clockwise direction in the
Northern hemisphere
Neÿl:rOÿ r0°
Microwaves - Electromagnetic waves
with wavelengths that are between
radio waves and infrared waves in the
electromagnetic spectrum
MiBky Way Galaxy - The huge grouping
of stars that rotate around a center of
which the Sun and the solar system are
a part
Luminosity/brightness - The intensity
Moon phase - The different shapes that
of light from a celestial body that can
the Moon seems to have as seen from
be used to determine differences in the
bodies
Earth
Lunar cycle - The Moon's repeated
pattern of movement and changes in
appearance due to its revolution around
Earth
Magnitude - A number describing the
size or quantity of something
Main sequence - Stable middle
development phase stars that plot
along a continuous diagonal belt on the
Hertzsprung-Russell Diagram
Marine ecosystem - An,ecosystem
found in oceans, seas, and gulfs where
the water has a salt content of at least
3.5%
IVletal - Element that is typically solid,
shiny, malleable, and good conductor of
heat and electricity; Most elements are
metals
Metalloids - Elements that have
properties of both metals and non-metals;
sometimes referred to as semiconductors
Earth, caused by the Moon's orbit around
Motion -The change in an object's
position with respect to time and in
comparison to the position of other
objects used as reference points
iÿlountain buiBding- The pushing up
of continental crust at the convergent
boundary of two continental plates of
equal density
Neap tide - Tides with the smallest daily
tidal range; occurs when the Sun, Earth,
and Moon form a 90 degree angle
Nebula - Large cloud of gas and dust
in interstellar space; the location of star
formation
Net charge- The sum of negative and
positive charges
Net force - The sum of all the forces
acting on an object
Neutron, no - A subatomic particle of the
nucleus of an atom that is without charge
that contributes to the mass of an atom
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GLOSSARY OF TERMS
Overofishing
New Fÿ 00t1
New moon - Phase when the Moon is
Nucleus - The tiny, very dense,
between the Sun and Earth and none of
the illuminated portion is seen from Earth
positively charged region in the center
of an atom; made up of protons and
neutrons
Newton's First Law of Motion (inertia)
-An object at rest will remain at rest
unless acted on by an unbalanced
force. An object in motion continues in
motion with the same speed and in the
same direction unless acted upon by an
unbalanced force
Newton's Second Law of Motion
(Force and Acceleration) - Acceleration
of an object depends on the object's
mass and magnitude of the force acting
upon it (F = ma) Acceleration is produced
when a force acts on a mass. The
greater the mass (of the object being
accelerated) the greater the amount of
force needed (to accelerate the object)
Ocean currents - A directional
movement of ocean water; surface
currents result from steady winds
over the ocean surface; deep currents
result from density variations due to
temperature and salinity differences
Ocean tide - Daily changes in the level
of ocean water due to the pul! of the
Moon's gravity on the water
Oceanic trench - Deep and narrow
depressions in the seafloor where
the subducted plate moves into the
asthenosphere
Omnivore-An organism that consumes
Newton's Third Law of Motion (Action°
Reaction) - For every action there is an
equal and opposite reaction
Nobme gases - Relatively unreactive
non-metals in Group 18 of the Period
Table
Non-metal - Element that is a poor
conductor of heat and electricity; usually
a gas or brittle solid, not malleable, and
typically not shiny
NucUear modeÿ of the atom - A
conceptual model of the atom in which
a small positively-charged nucleus is
surrounded by planetary electrons;
based on an experiment done by Ernest
Rutherford in 1909
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both animals and plants
OrbitaB path -The gravitationally-curved
path of an object around a point in space
Origin - Point at which something
begins, or from which it derives
Outermost eUectron caoud - The
number of electrons in a partially-filled
outermost electron shell (or shells)
determine the chemical properties of the
atom; it is called the valence shell
Over-fishing - Harvesting (fishing) a
resource (fish) so much that the species
population is unable to reproduce enough
to replace the ones taken; also called
over-harvesting
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GLOSSARY OF TER IS
Reactivity
Parasite
Parasite -An organism that survives in
or on a host organism and causes harm
to the host
Proton, p* - A positively charged
subatomic particle of the nucleus of an
atom that contributes to the mass of the
atom
Periodic Table of Elements -A table
that organizes the known elements
by order of increasing atomic number
and where elements that share similar
properties are arranged in vertical
columns, or groups
Periods (of elements) -The rows in a
Periodic Table that classify the elements
by the number of electron shells
Plate tectonic theory = Theory that
the lithosphere is divided into very large
tectonic plates that slowly move on top of
the asthenosphere
Pollution - Harmful substance that
contaminates a natural environment
Precipitate -An insoluble solid that forms
out of solution during a chemical reaction
Predator- An organism that hunts for its
food
Prey -An organism that is hunted by
other organisms for food
Producer- An organism that is capable of
performing photosynthesis, transforming
energy from the Sun, and using carbon
dioxide and water to make food
Products - A substance produced during
a chemical reaction
Property- The physical and chemical
characteristics of a substance or element
Psychrometer - a hygrometer consisting
essentially of two similar thermometers
with the bulb of one being kept wet
so that the cooling that results from
evaporation makes it register a lower
temperature than the dry one and with
the difference between the readings
constituting a measure of the dryness of
the atmosphere
Radiation - The transfer of
energy through matter or space as
electromagnetic waves, such as visible
light and infrared waves
Radio astronomy - The study of
celestial objects that emit radio waves
Radio waves - Electromagnetic
waves with long wavelengths and low
frequencies
Reactants - A substance that takes
part in and undergoes change during a
reaction
Reaction - 1) (chemistry) another name
for a chemical change, 2) (physics)
Resistance or force of equal magnitude
acting in the opposite direction to an
action force
Reactivity - Rate at which a chemical
substance tends to undergo a chemical
reaction; significantly influenced by
valence electrons of the reacting
substances
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GLOSSARY OF TERMS
Red shift
Spiraÿ arms
f
Red shift- An apparent lengthening of
the wavelength of light toward the longer
(red) end of the visible light spectrum as
the distance between the source and the
observer increases. It is not a shift in the
actual frequency from the source
Revolve, revolution -To move in a
circle around another object; Earth's
yearqong elliptical orbit around the Sun
Rotate, rotation - To spin on an axis; the
spinning of Earth on its axis that causes
day and night to occur
Runoff- Rainfall and surface water
that drains or flows from the land into
streams, rivers and lakes or the ocean
Satellite views - Photos or images from
space taken of Earth over time; can be
used for comparison and interpretation of
Sea floor spreading evidence-A
parallel pattern of rock material found at
identical locations on each side of the
Mid-Atlantic Ridge reveals rock of the
same geologic age and polarity
Seasons - The four natural divisions
of the year based on changes in
temperature due to the varied amounts
of sunlight (both intensity and number of
daylight hours received); caused by the
tilt of Earth's axis related to the Sun's
location during revolution
Sediment deposition - Occurs when
solid fyagments of weathered rock are
eroded, (moved) and then dropped into a
newiÿiiace by wind, water, ice, and gravity
Short-term environmental change-
Environmental change that occurs quickly
and affects organism immediately
erosional features, such as these taken
of the Yellow River Delta
Soÿar mass -An astronomical unit
of mass equal to the sun's mass,
Scale model -A representation of an
object that is accurate in its proportions to
the actual object
1.981 x 1030 kilograms Used in
astronomy as a standard unit to compare
the size of other stars with our Sun
Scientific notation - Numbers written
in terms of a decimal number between
Solar radiation - The electromagnetic
energy emitted from the Sun
one (1.0) and ten (10.0) multiplied by a
power of ten. For example, the scientific
notation for ten thousand four hundred
ninety-two (10,492) is 1.0492 x 104
Scientific theories - Unifying scientific
explanations for a broad range of
hypotheses and observations that have
been supported by scientific experiments
Speed - A measurement of the rate of
change of position with respect to time
Speed of light - How fast light travels;
300,000 km/sec
Spiraÿ arms - Areas of stars that spread
out from the center of a spiral galaxy
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GL©SSARY OF TSRM8
Spiral°shaped gamaxy
Uÿtraviolet waves
f
SpiraJoshaped gaUaxy - A galaxy with a
bulge in the center and very distinct long
arms winding around the center
Supernova - The explosion Of a large
star followed by fading and sometimes its
collapse
Spring tide - Tide with the largest daily
Terrestrial ecosystem- An ecosystem
tidal range; occurs when the Sun, Earth,
and Moon line up with each other
that is found on land
Star- A self-luminous celestial body
consisting of a mass of gas held together
by its own gravity in which the energy
is generated by nuclear reactions in its
interior
Subatomic particles - Particles that
are smaller than the atom, e.g. protons,
neutrons and electrons
Thermal energy - A form of energy
internal to matter as the total kinetic
energy (motion) of atoms and molecules
in the matter. The fast the atoms move,
the warmer the matter
Tidaÿ effect - Bulges in the oceans
toward and away from the Moon is
response to the pull of its gravity on
the water. The difference between the
heights of the high tide and the low tide
Subduction -The process in which
a denser tectonic plate is pushed
downward beneath a less dense
plate when plates converge; occurs at
continental to oceanic boundaries and
oceanic to oceanic boundaries
Subscript - A number written below and
in an area is due to the change in the
Moon's position
TiUt - The slant of Earth's axis, which is
23.5 degrees from vertical compared to
Earth's orbital plane around the Sun. As
a result, the North Pole always points
toward the North Star
to the right of a chemical symbol that
shows the number of a specific type of
atom present in a molecule
Topographic map -A map showing
changes in elevation of Earth's surface
Substance - Form of matter that has
constant chemical composition and
specific properties. It cannot be separated
into components by physical separation
methods. Element or compound that can
only be separated or combined to make
substances with new properties by means
of a chemical reaction
Transform boundary- The boundary
between two tectonic plates that slide past
one another; sudden shifts result in major
geological events such as earthquakes
and the release of stored energy
Trophic Ueveÿ- The position an organism
occupies on a food chain
Sun - The luminous star around which
the Earth and other planets revolve;
composed mainly of hydrogen and helium
UItravioUet waves - Electromagnetic
waves with a shorter wavelength than
visible light, but longer than x-rays
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GL©SSARY OF TER S
Unbalanced forces
Unbalanced forces - Forces on an
object that cause change in the motion of
Xorays
Weather = The day-to-day state of the
atmosphere
the object
space contains
Weather map -A map or chart shows
the weather conditions at a specific point
in time over a specific region
Valence electrons -The electrons in the
outermost energy level of an atom that
influence how an element will react with
other substances
Weather system - A specific set
of weather conditions occurring in
the lowest levels of the atmosphere,
reflecting the configuration of air
Universe -All space and the matter
movement
Velocity - Measurement of speed and
direction of an object
Waning - When the Moon appears to be
getting smaller
Warm front- The leading edge of a
warm, moist air mass that overtakes a
.cool, dense, and dryer air mass
Weathering -The mechanical or
chemical processes that break rocks into
sma, ller pieces and sometimes change
the chemical composition
Wind - A natural movement of air
sometimes with considerable force from
an area of high density and pressure to
an area of low
Wavelength -The distance between
any two corresponding points that are
adjacent on a wave, such as from peak to
peak
Xorays - Electromagnetic waves that
are the second highest in energy and
are used in medical and astronomical
applications
Waxing - When the Moon,appears to be
getting larger
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Eventually, sediments being carried by erosion stop moving and settle out in a new
location. This process is called deposition. Sediments are generally deposited in horizonta
layers. The older layers are on the bottom, and the newer layers are on the top.
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Erosion is the process by which rocks, sediments, or bits of soil are carried away. Agents
of erosion include flowing water, ice, wind, and gravity. (An agent causes something
to happen.) As sediments are moved, they can scrape against other rocks, causing
mechanical weathering at the same time as erosion. Because weathering and erosion
can occur at the same time, rocks that are carried long distances by erosion tend to be
more weathered, making them smaller and more rounded. Rocks that are carried shorter
distances, particularly through gravity, tend to be in larger, more angular pieces.
/
Topography and Satellites
Topography refers to the steepness or flatness of the land. (This is also called retie/'.)
Topography includes features such as mountains, hills, cliffs, valleys, and depressions.
The processes of weathering, erosion, and deposition can change the topography of an
area over time. For example, winds and gravity can lower the elevations of mountains by
breaking them down and carrying away their rocks. Flowing rivers and moving glaciers can
also cut canyons into the ground.
:i
Scientists can track these changes in topography over time using satellite technology.
Satellites are manmade instruments that are launched into space and that orbit Earth.
Many satellites are equipped with powerful cameras. These cameras can photograph
landforms and other features from space. This provides a large-scale view of the
topography of an area, which allows scientists to study major features and patterns in ways
that would otherwise be impossible. Because satellites orbit Earth, they can photograph
the same area every time they pass over it. This allows scientists to study the changes in
topography that weathering, erosion, and deposition can make over time.
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Both photographs on the next page were taken by a satellite. The photograph on the left
shows China's Yellow River Delta in 1989. The photograph on the right shows the same
region in 2009. How did the region change between 1989 and 2009? (HINT: Brown areas
show land, and blue areas show water.) How might we'athering, erosion, and deposition
have caused these changes?
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