Earth Science Flashcards
apparent vs. actual motion
actual motion is the motion we know (to travel from point A to point B) while apparent motion is an optical illusion that causes stationary objects to appear moving due to one’s own movement
why are there seasons?
Earth’s axial tilt
what is the degree of Earth’s tilt?
23.5 degrees
How many days does a full moon cycle take?
29.5 days
list all of the lunar phases and the details
New moon (darkness), waxing crescent (sliver, occurs when moon is growing/waxing), first quarter moon (1/2 moon in the first quarter of cycle), waxing gibbous moon (wierd egg shape when moon is growing/waxing), full moon (whole moon can be seen), waning gibbous, 3/4 moon, waning crescent
what causes water tides and keeps the earth’s axis stable?
the moon (gravity)
why does a lunar eclipse happen?
when the earth is behind the sun and the moon is behind the earth
full vs. partial lunar eclipse
full means the earth’s shadow fully covers the moon which causes the moon to appear orange, partial means some sunlight directly reaches the moon.
why does a solar eclipse happen?
the moon’s shadow blocks the sun from shining on earth
total vs. partial solar eclipse
moon completely shadows the earth vs. moon partially shadows the earth
what part of the sun is only visible during a solar eclipse
the corona
what does weather result from
air masses moving from places of high air pressure to low air pressure
high vs. low pressure system
the high pressure causes air to disperse from its core which causes clear skies, while low pressure causes air to go to the core which causes more extreme weather
low pressure systems are associated with a ____ which is _____
front, which is a boundary that forms when air masses with different temperatures collide near the surface
warm front vs. cold front
a warm front occurs when a warm air mass goes into a cold air mass place; the warm air goes above the cold air. Cold front occurs when a cold air mass goes into a warm air mass palce
where is pressure highest and lowest and why
the poles have high pressure because the cool air sinks while the equator has low pressure because the warmer air rises
what causes wind currents?
air flowing from high to low pressure
prevailing winds, gyres
global wind patterns, giant rotational systems of ocean currents that form when smaller ocean currents combine
why do wind patterns and current patterns travel in curves; to the right in the northern hemisphere and to the left in the southern hemisphere? What is this phenomenon called?
the direction of Earth’s rotation, the Coriolis Effect
what causes surface currents in the ocean?
the wind driving the water
what are deeper ocean currents affected by and how to they move?
temperature and density, they move vertically
upwelling, overturning circulation
wind drags deep water to the surface, system of surface and deep water currents
continental vs. marine climate
continental climate has temperatures that vary much more than in a marine climate; this is due to water’s high heat capacity
rain shadow
a phenomenon caused by mountains that results in one side of the mountain getting less rainfall than the other (which is due to the mountains blocking warm air).
igneous rock (90% of earth’s crust)
formed when molten liquid rock (which is formed due to the right combination of heat and pressure) cools
types of molten rock and where they are found
magma (below Earth surface) and lava (above Earth’s surface)
rock weathering, sediments, sedimentary rocks, metamorphic rock
weather, wind, etc. begin to chip away at a rock, the pieces that fall off of the rock are sediments, rocks formed from sediments, rocks that change composition when heated and squeezed a lot
erosion
the sediments from the rock are taken away from wind, weather, etc.
lithification (include step names)
1) deposition - sediment in a new location spreads out to form a layer
2) compaction - as more sediment layers form, the layers below them are compressed
3) cementation - as water (carrying minerals) moves through the sediment layers, it leaves behind minerals that make the sediments stick together
law of superposition, law of crosscutting relationships
states that the bottom layers of sediment are always older than the top layers, when 2 geological features cross each other, the feature that cuts through the other is younger
igneous intrusion, index fossils
a layer of rock that slices through many layers of rock in sediment, fossils that are only found on a specific section of the geological timescale
lithosphere and what is broken up into
crust + upper mantle, tectonic plates
asthenosphere
section of mantle below lithosphere
big continent
pangea
divergent, convergent, and transform boundaries
moving apart from each other, moving into each other, sliding across each other
what causes earthquakes
when the friction between transform plates causes them to slip
why do tectonic plates move?
gravity
types of tectonic plates and crust they are made of
continental (Granite - rock that was once molten) and oceanic (basalt). Oceanic is denser
How does density affect plates?
it means that oceanic plates sink into the asthenosphere below the continental plates
the place where convergent plates bend into each other in the ocean. What do these create?
subduction zone, creates trenches
How are volcanoes formed
The oceanic plate that dips below the continental plate usually has water in it. This water heats and bubbles to the surface. The hot fluids melt the rock and create magma, which results in volcanoes on the surface
how is new sea floor created?
a divergent boundary of plates creates a mid-ocean range (underwater mountains). Then magma rises to the surface, cools, and creates a new lithosphere.
weathering vs. erosion
weathering is when elements break rocks apart while erosion is when water carries away soil, sediments, and rocks
mechanical weathering
rain is powerful enough to break down soil. As rain accumulates, it can erode a landscape.
chemical weathering
acids in water break down rocks and minerals
how do cave systems form
limestone is broken down due to carbonic acid in the water, over time.
costal erosion
waves cause rock to break away over time
