EARTH SCIENCE STUDYGUIDE MODIFIED

significant figure

each of the digits of a number that are used to express it to the required degree of accuracy, starting from the first nonzero digit; any non-zero number; any zero “sandwiched” between two numbers

when we use significant figures

collecting data, calculating data, answering number based science questions

why to use significant figures

better measurement and precise answers

counting significant figures

count the number of digits in a given number; don’t count zeros at beginning or end of a number, only the zeros between two numbers (ex. 12,067 has 5 sig figs but 1200 has 2 sig figs); zeros can be significant at the end of the number if they’re in a data set

rule for significant figures in data sets

every number in a data set has to have the same number of significant figures

scientific notation

used to make it easier to write out very large and small numbers; helps to put large numbers into sig figs (ex. 4.500000 \= 4.5 * 10^6)

coefficient in scientific notation ex.

4.5

base in scientific notation ex.

10

exponent in scientific notation ex.

^6

universe

all matter, time, energy, and space

observation

perception of an aspect of the environment using human senses (sight, hearing, touch, taste, or smell)

instrument

device that extends the senses beyond their normal limits, allowing them to make observations that would be impossible or highly inaccurate (ex. microscope)

inference

interpretation of an observation

classification

grouping similar things in the environment

measurement

numerical value; includes length, mass, or time

mass

amount of matter in an object; found with balance

length

distance between two points

time

duration of an event

volume

amount of space an object occupies; for solid objects, found by finding the volume of water an object displaces with an instrument (graduated cylinder)

percent deviation

percent error; obtained by dividing the difference between the measured and accepted values by the accepted value and multiplying the result by 100%

density

concentration of matter in an object; doesn’t depend on size or shape of the sample as long as temperature and pressure remain the same

if the density of the object is less than the liquid…

it will float

if the density of the object is greater than the liquid…

it will sink

if the density of the object is the same as the liquid…

it will remain stationary somewhere in the liquid

if the temperature of a gas increases and its pressure stays the same…

the density of the gas decreases

if the pressure on a gas increases…

the density of the gas increases

phases of matter and density

all substances increase in density when they change from gas to liquid and from liquid to solid (molecules are closer together in solids and far apart in gases). only exception is water because ice floats on liquid water

rate of change

how much a measurable aspect of the environment (a field) is altered over a given time (years, hours, or seconds)

cyclic change

changes in the environment that constantly repeat; an orderly change (ex. movement of the planets)

prediction

a type of inference; educated guess

natural hazard

a dangerous, non-human-related object, process, or situation (ex. earthquake)

interface

boundary between regions with different properties; where energy is exchanged across

dynamic equilibrium

opposing forces or actions balancing out (ex. lake level remaining the same after water moves in and out of the lake)

environmental equilibrium

natural balance among all changes taking place

natural resources

materials and energy sources found it the environment that humans use in their daily lives (ex. water, air, fossil fuels)

pollution

occurs when the concentration of any substance or form of energy reaches a proportion that adversely affects people and the environment (ex. dirty air caused by technology)

natural pollution

pollution that occurs without the presence of people (ex. volcanic ash and gases from eruptions)

model

is a way of representing the properties of an object or system

atmosphere

layer of gases that surrounds Earth above the surface of liquid water and rocky material; composed mostly of nitrogen and oxygen; the least dense layer

pauses (of atmosphere)

the interfaces, or boundaries, of the layers of Earth’s atmosphere

hydrosphere

layer of liquid water that lies between the atmosphere and much of the upper layer of the upper layer of Earth’s interior; consists of bodies of water (70% of Earth’s surface); relatively thin

lithosphere

layer of rock that forms the outer solid shell at the top of Earth’s interior; beneath the atmosphere and hydrosphere

crust

upper portion of the lithosphere; covered by soil when not covered by bodies of water

Earth’s interior

region extending from the rocky part of Earth’s surface to Earth’s center (geosphere)

biosphere

layer of living things

magnetosphere

Earth’s magnetic field

cryosphere

ice/solid water

coordinate system

latitude-longitude coordinate system used to locate points on Earth’s surface

latitude

distance north and south of the equator;

increasing latitude means…

moving towards the geographic poles

decreasing latitude means…

moving towards the equator

equator

middle location on Earth’s surface; halfway between North and South poles

longitude

distance east or west of the prime meridian

increasing longitude means…

going towards the 180 degree meridian

decreasing longitude means…

moving towards the prime meridian

prime meridian

zero longitude

field

any region of space or the environment that has some measurable value of a given quantity at every point (ex. temperature)

isolines

varying values of a field represented on maps by the use of lines that connect to points of equal field values

isolines closer together means…

steeper slopes/greater gradient

contour lines

connect to points of equal elevation

gradient

slope; the rate of change from place to place within a field

topographic map

contour map; model of the elevation field of the surface of Earth

elevation

vertical distance or height above or below sea level

profile

side view of an area’s landscape; uses upward and downward changes of a line to show changes in elevation and slope

celestial object

any object outside or above Earth’s atmosphere

universe

all matter, time, space, and energy

big bang theory

the start of the universe atoms became celestial bodies which then became part of gravitational groupings

doppler effect

the position of the characteristic wavelengths, or colored lines, are shifted to either the shorter (blue end) or longer (red end) wavelengths

red shift

when electromagnetic waves (light) are spread out

star

a large ball of gas held together by gravity that produces tremendous amounts of energy

galaxy

collection of billions of stars and various amounts of gas held together by gravity

milky way

our galaxy (the gravity we live in)

nuclear fusion

the combining of the nuclei of smaller elements to form the nuclei of larger elements with some of the mass being converted into energy

luminosity

the actual brightness of a star or rate of total energy emitted compared to the Sun

absolute magnitude

a star’s brightness at a standard distance

as a star’s surface increases…

stars change color from blue to red

solar system

the sun and all objects that orbit the sun under its gravitational influence

asteriod

a solid, rocky and/or metallic body that independently orbits the sun

moon

a body that orbits a planet or an asteroid as those objects orbit the sun

comet

mainly composed of solids that easily change to gases when heated

meteors

when meteoroids burn up or vaporize, they leave a brief visual streak as they pass through Earth’s atmosphere

impact crater

when some meteorites have sufficient mass to create a depression in Earth’s crust

impact event

when the gravitational forces of planets are pulled on the smaller clumps of matter to cause comets, asteroids, and meteoroids to collide with the planets

terrestrial planets

close to the sun and mostly solid (Mercury, Venus, Earth, and Mars)

jovian planets

far from the sun and largely gaseous (Jupiter, Saturn, Uranus, and Neptune)

rotation

when planets spin on an imaginary axis

period

time it takes to complete one rotation (cyclic event)

revolution

its movement around the sun in a path called an orbit

ellipse

oval shape of planetary orbit

foci

(focus) two fixed points within the ellipses

eccentricity

degree used to measure an ellipse’s flattening or “ovalness”

inertia

an object at rest will remain at rest and an object in motion will remain in motion unless acted on by an outside force

gravitation

attractive force that exists between any two objects in the universe

apparent motion

a motion that an object appears to make; can be real or illusions

retrograde

when a planet appears to move backward due to its own orbit around the Sun; only moving backwards from Earth’s perspective

arc

the paths of all celestial objects moving in the sky are circular; parts of a circle

when does an arc length change?

the position and length of that arc changes with the seasons

daily motion

movements of celestial objects over a 24-hour period

apparent motions of Earth’s moon

follows the daily east-to-west motion of the stars (shifts eastward each day)

the greater length of the sun’s path over an area…

the more hours of daylight the area has