7th Grade Final-2014 Flashcards
conditions in the atmosphere that change from day to day; determined by factors such as air pressure, humidity, and wind
weather
a region’s general pattern of weather over a long period of time; influenced by factors such as latitude, landforms, and ocean currents
climate
the Earth’s air; a mixture of gases, solids, and liquids that surround the Earth; divided into distinct layers
atmosphere
generates air movement (wind) and ocean currents; results when cooler, denser material sinks, while warmer, less dense material rises
convection current
narrow belts of strong winds; they form between cold, dry polar air and warm, moist tropical air
jet stream
the boundary between 2 air masses with different temperature and moisture levels; usually results in stormy weather
front
a measure of the force exerted by air on all objects; decreases rapidly as altitude increases
air pressure
usually associated with dry weather and mostly clear skies; wind circulate in a clockwise direction
high pressure
usually associated with clouds and precipitation; winds circulate in a counterclockwise direction
low pressure
warmer than normal sea-surface temperatures in the Pacific Ocean; impacts global weather patterns; creates wetter than normal conditions in the southwest United States
El Nino
boundary between a cold and a warm air mass, where the colder air replaces the receding warmer air
cold front
boundary between a cold and a warm air mass, where the warmer air replaces the receding colder air
warm front
oval or egg-shaped; such as in Earth’s path around the Sun
elliptical
one of the 2 halves into which Earth is divided; the imaginary dividing line is called the equator
hemisphere
an imaginary line drawn around the Earth; divides the Earth into Northern and Southern Hemispheres
equator
either the shortest day of the year during winder or the longest day of the year during summer in the Northern Hemisphere
solstice
a day during the autumn and spring when the periods of light and dark hours are equal
equinox
occurs when the Moon passes between the Sun and the Earth; or when the Earth passes between the Sun and the Moon blocking our view
eclipse
the regular cycle of change in the appearance of the moon (29.5 days); depends on relative positions of the Moon, Earth, and Sun
moon phases
to increase in size or intensity; when more and more of the lighted surface of the Moon is visible from Earth
waxing
to decrease in size or intensity; when less and less of the lighted surface of the Moon is visible from Earth
waning
when more than half (but not all) of the Moon’s lighted surface is visible from Earth
gibbous
when the lighted side of the Moon faces away from Earth and is not visible; the Moon is between the Sun and the Earth
new moon
when a small C-shaped portion of the Moon’s surface is visible from Earth
crescent
the force of attraction between 2 objects; depends on the mass of the objects and the distance between them
gravitational attraction
when the Sun, Earth, and Moon are precisely aligned, the Moon passes into the shadow of the Earth; Earth prevents sunlight from reaching the Moon
lunar eclipse
when the Moon passes between Earth and Sun and casts a shadow upon Earth’s surface; some portion of the Sun’s disk is covered by the Moon
solar eclipse
the alternating rise and fall of the Earth’s oceans
tides
when ocean water is at its greatest elevation or level; most places in the ocean experience 2 per day
high tide
when ocean water is at its lowest elevation or level; most places in the ocean experience 2 per day
low tide
states that the universe started about 12-15 billion years ago with an enormous explosion, resulting in an expanding universe
Big Bang Theory
a cloud of gas and dust in space; it contracts under gravitational force; it is where new stars are formed
nebula
huge sphere of very hot, glowing gas that produces its own light and energy in a process called nuclear fusion; our Sun is an example
star
a graph showing the relationship between a star’s temperature and its absolute magnitude or luminosity
H-R diagram
a measure of the brightness of a star; can be either the amount of light given off (absolute) or the amount of light received on Earth (apparent)
magnitude
a large grip of stars, gas, and dust help together by gravity; classification is based on shape, such as spiral, elliptical, or irregular
galaxy
a group of stars forming a pattern that is traditionally named after its apparent form or a mythological figure
constellation
measures the total amount of energy emitted by a star or other astronomical object
luminosity
a region of space-time whose gravitational field is so strong that nothing which enters it, not even light, can escape
black hole
the distance that light can travel in one year; equal to 9,500,000,000,000 km
light year
a celestial body or manmade object that orbits a planet such as a moon or the Hubble space telescope
satellite
an optical instrument, using a special arrangement of lenses and mirrors, that makes distant objects appear closer
telescope
hottest, innermost, solid, dense center of the Earth; consists mainly of iron under great pressure
inner core
liquid layer of the Earth’s core composed of iron and nickel; located just below the mantle
outer core
solid/plastic layer in Earth’s interior between the crust and the outer core; separated into upper and lower regions
mantle
the part of Earth’s crust located under the ocean water; younger in age, thinner, and more dense
oceanic crust
the part of Earth’s crust located under the continents; older in age, thicker, and less dense
continental crust
a fracture in the Earth’s crust where stress builds up and movement occurs
fault
1912 hypothesis developed by Alfred Wegener; stating that continents were once connected “like puzzle pieces,” then drifted apart
continental drift
theory the Earth’s lithosphere (outer rigid layer) is composed of pieces, or “plates,” that move as a result of convection in the mantle
plate tectonic theory
the outer, rigid, solid part of the earth, including the crust and the uppermost part of mantle; it is about 100 km thick
lithosphere
where 2 tectonic plates are moving away from each other, new crust is created; such as in mid-oceanic ridges
divergent boundary
where 2 tectonic plates are moving towards each other, crust is destroyed; forms oceanic trenches, mountains, and volcanic islands
convergent boundary
where 2 tectonic plates slide against or past each other, crust is not created or destroyed; earthquakes result
transform boundary
photographs taken from space and transmitted to Earth by artificial satellites, such as the Hubble telescope
satellite image
water that collects in cracks and spaces in soil, sand, and rock; can be stored in aquifers
groundwater
water moving according to the laws of gravity from higher to lower elevation (downhill)
runoff
the breaking down of rocks, soils, and minerals by mechanical or chemical processes
weathering
the processes by which soil and rock are removed and transported, such as by wind or water flow
erosion
the accumulation of sediment transported by wind or water; happens when erosion stops and particles settle on a surface
deposition
