Earth Science Final Exam Study Guide

Pangaea
the name given to the early super-continent
continental drift
a hypothesis that Earth’s continents had once been joined as a single landmass
magnetometer
a device that can detect small changes in magnetic fields
paleomagnetism
the study of the magnetic record of the seafloor
magnetic reversal
a change in Earth’s magnetic field
isochron
a line on a map that connects points that have the same age
seafloor spreading
a theory that states the new ocean crust is formed at ocean ridges and destroyed at deep-sea trenches
plate tectonics
a theory that states the Earth’s crust is broken in to enormous slabs called plates
divergent boundaries
places where two tectonic plates are moving apart
rift valley
when continental crust begins to separate that stretched crust forms a long narrow depression
transform boundary
place where two plates slide horizontally past each other
convergent boundaries
places where two tectonic plates are moving toward each other
subduction
the process of one plate descending beneath another
ridge push
the weight of the uplifted ridge pushes an oceanic plate toward a trench
slab pull
the weight of the subducting plate helps pull the trailing plate into the subduction zone
Wegener
Proposed the theory of continental drift
flat
scientists thought the seafloor was this?
mid-ocean ridges
new crust is formed at where?
near deep-sea trenches
sediments on the ocean floor are deeper where?
seafloor spreading
discovery that led scientists to eventually accept the theory of continental drift
viscosity
internal resistance to flow
plutons
intrusive igneous rock bodies caused by magma
lava
when magma reaches Earth’s surface
vent
an opening in the Earth’s crust through which magma reaches the surface
crater
a bowl shaped depression at the top of a volcano
caldera
a depression greater than 1 km in diameter at the top of a volcano
shield
type of mountain with broad, gently sloping sides and a nearly circular base
cinder-cone
a type of volcano that forms when material is ejected high into the air and falls back and piles up around the opening
composite
a type of volcano that forms when layers of volcanic fragments alternate with lava
tephra
rock fragments thrown into the air during a volcanic eruption
Pyroclastic
flow that refers to rapidly moving volcanic material sent down a slope during an eruption
Hot spots
unusually hot regions of Earth’s crust where high temperature plumes of mantle material ruse toward the surface
lower
A wet mineral or rock will melt at a ________ temperature?
high
Magma with ________ viscosity is more explosive.
increases
increasing silica content has what effect on the viscosity of magma?
batholiths
large plutons common in the interior mountain chains
stocks
smaller, similar to batholiths
laccolith
mushroom shaped with round top and flat bottom
dikes
cuts across preexisting rocks
sills
magma that intrudes parallel to rock layers
stress
the force per unit area acting on a material
strain
the deformation of materials in response to forces acting on them
focus
the point where an earthquake originates
epicenter
the point on Earth’s surface directly above where an earthquake originates
seismometer
a device that detects and records the vibrations caused by an earthquake
magnitude
a measure of the amount of energy released during an earthquake
Richter
the scale that is based the size of the largest seismic waves produced by an earthquake
tsunami
a large ocean wave generated by vertical motion of the seafloor during an earthquake
seismic gaps
sections of active faults that have not experienced significant earthquakes for a long period of time
faults
fractures in Earth’s crust along which movement occurs
intensity
how much damage the earthquake caused
weathering
the process by which rocks on or near Earth’s surface break down and change
erosion
the removal and transport or weathered material from one location to another
mechanical weathering
the process by which rocks and minerals break down into smaller pieces
frost wedging
the repeated thawing and freezing of water in the cracks of rocks
exfoliation
process by which outer rock layers are stripped away
chemical weathering
the process by which rocks and minerals undergo changes in their composition as the result of chemical reactions
hydrolysis
the reaction of water with other substances
oxidation
the chemical reactions of oxygen with other substances
deposition
the final stage of the erosional process
rill erosion
the erosion by running water in small channels, on the side of a slope
gully erosion
when a channel becomes deep and wide
soil
the loose convering of broken rock particles and decaying organic mater overlying the bedrock of Earth’s surface
residual soil
soil located above parent material
transported soil
soil that has been moved to a new location away from its parent bedrock
soil horizon
a distinct layer within a soil profile
soil profile
the vertical sequence of soil layers
mass movement
the downslope movement of loose sediments and weathered rook resulting from the force of gravity
creep
the slow, steady, downhill flow of loose weathered Earth materials
mudflows
swiftly moving mixtures of mud and water
landslide
a rapid, down slope movement of Earth materials that occur when a relatively thin block of loose soil, rock, and debris separates from underlying bedrock
slump
when the mass of material in a landslide rotates and slides along a curved surface
avalanches
landslides that occur in mountainous areas with thick accumulations of snow
deflation
the lowering of the land surface that results from the wind’s removal of surface particles
abrasion
occurs when particles such as sand rub against the surface of rocks or other materials
ventifacts
rocks shaped by wind-blown sediments
dune
pile of wind-blown sand that develops over time
loess
thick, wind-blown silt deposits
glaciers
a large, moving mass of ice
valley glaciers
glaciers that form in valleys in high, mountainous areas
continental glaciers
glaciers that cover broad, continent-sized areas
cirques
deep depressions
moraines
ridges consisting of till deposited by glaciers
outwash plain
the area at the leading edge of the glacier, where the meltwater streams flow and deposit outwash
drumlins
glaciers that move over older moraines from the material into elongated landforms
eskers
long, winding ridges of layered sediments that are deposited by steams flowing under a melting glacier
wetland
a land area that is covered with water for a large part of the year
eutrophication
process by which lakes become rich in nutrients form the surrounding watershed
lake
a depression in the landscape that collects and holds water
rejuvenation
when a stream actively resumes the process of downcutting toward its base level
meander
a bend or curve in a stream channel caused by moving water
stream bank
the ground bordering the stream on each side
delta
the triangular deposit that forms when a stream enters a large body of water
stream channel
the narrow pathway cut into the sediment or rock by moving water
floodplain
the broad flat area that extends out from the stream bank and is covered by excess water during times of flooding
flood
occurs when water spills out over the sides of a stream’s bans onto the adjacent land
bed load
consists of the sand, pebbles, and cobbles that are pushed or rolled along the bed of a stream
suspension
particles held up by the turbulence of a stream’s moving water
divide
a high land area that separates one watershed from another
watershed
all the land area whose water drains into a stream system
runoff
water flowing downslope along Earth’s surface
hydrosphere
all the water on Earth’s surface
infiltration
the process by which water enters the ground
porosity
the percentage of pore space in a material
water table
the upper boundary of the zone of saturation
permeability
the ability of a material to let water pass through
aquifers
permeable layers through which groundwater flows
cave
a natural underground opening with a connection to Earth’s surface
sinkhole
a depression in the ground caused by the collapse pf a cave or by the dissolution of bedrock
stalagmites
dripstone deposits on the floor of caves
springs
natural discharges of groundwater
geysers
explosive hot springs
drawdown
the difference between the original water table and the water level in a pumped well
recharge
water from precipitation and runoff is added back into the zone of saturation
hot springs
springs with a temperature that is higher than that of the human body
acquicludes
impermeable layers that are barriers to groundwater flow
beach
a sloping band of sand, pebbles, gravel or mud at the edge of the sea
margin
the submerged parts of the continents
turbidity currents
rapid flowing water currents along the bottom of the sea that carry heavy sediment loads
rise
a deposit at the base of the continental slope is called a continental ________.
abyssal plain
the smooth parts of the ocean floor
seamounts
submerged basaltic volcanoes more than 1km high
oceanography
scientific study of oceans
sea level
the level of the oceans’ surface
salinity
a measure of the amount of dissolved salt in seawater
thermocline
the layer of the ocean characterized by rapidly decreasing temperature with depth
crest
the highest point of a wave
wave
a rhythmic movement that carries energy through space or matter
tides
the periodic rise and fall of sea levels
breakers
collapsing waves
trough
the lowest point of a wave
density currents
currents cause by differences in the temperatures and salinity of ocean currents
upwelling
the upward movement of the ocean water
estuary
the area where the lower end of a freshwater river or stream enters the ocean
shelf
the shallowest part of the continental margin extending seaward is the continental _______.
70%
What percentage of Earth’s surface is below sea level?
continental slope
What marks the true edge of a continent?
mud
What do the sediments of the abyssal plain mostly consist of?
Which represents the flattest part of Earth’s surface?
abyssal plains
What is the average salinity of seawater?
35 ppt
Which type of seawater has the greatest density?
cold with high salinity
What is the average depth of the oceans?
3800m
Which are the most common gases emitted by volcanoes?
water vapor and carbon dioxide
Which of the following is used to measure ocean depth?
sonar
What type of high tides occurs during a full moon?
spring tides