Science Mid- term
secondary wave
(s-waves)- the second set of waves to be felt, waves travel vertically, slower than p-waves
mantle convection
....is modeled by the water movement
3 million years
Approximately how long did the Gauss epoch last
vertical
In which direction is the movement in a reverse fault?
continental drift
Wegener's hypothesis
It returns to its original shape
What happens to a rock that undergoes elastic deformation once the stress is removed?
Gilbert
Which epoch saw the most fluctuations between normal and reverse polarity
folded mountains
Which figure forms along this boundary?
volcanism
_________not a force causing plates to move
crater
a bowl-shaped geological formation at the top of a volcano: lava travels through a conduit to erupt through this
continental- continental
a convergent boundary that does not have a subduction zone
magnetometer
a device that measures magnetism
rift valley
a divergent boundary within a continent forms this
isochron
a line on a map that denotes crust that formed at the same time
Richter scale
a numerical rating system that measures the energy of the largest seismic waves
elastic deformation
deformation causes a material to bend and stretch
Volcanism
refer to all processes associated with the discharge of magma , hot water, and steam
surface waves
slowest type of waves, only travel along earth's surface. cause the ground to move sideways and up and down like ocean waves
shape of continents
suggested to early cartographers that the continents were once joined
older than the continental crust
the age of oceanic crust is...
seismograph
the amount of energy released and the amplitude of seismic waves are measured by the scale known as...
modified mercalli scale
the damage by earthquakes is described by...
strain
the deformation caused by stress
sea-floor spreading
a process that creates new ocean crust by the up-welling of magma at ocean ridges
Moment- magnitude scale
a rating scale that measures the energy released by an earthquake
faults, or plate boundaries
a region where earthquakes are expected but none have occurred for a long time
tsunami
an underwater earthquake causes the movement of a column of water resulting in a ...
The Pacific Ocean
area surrounded by the Ring of Fire
ridge push
as the older portion of the sea-floor sinks, the weight of the uplifted ridge is thought to push the oceanic plate toward the trench formed at the subduction zone
tepra
ash is the smallest type of .....
convergent boundary
boundary where two plates come together
calderas
forms in the depression that surrounds the vent at the volcanoes summit
centimeters per year
how fast do plates move relative to each other
tectonic plates
huge pieces of crust and rigid upper mantle that fit together at their edges to cover earth's surface
composite volcano
in the most explosive types of eruptions, lava accumulates to form this..
Continental drift
the idea that continents now separated by an ocean were once attached
Pangea
the name given to a single continent that existed 200 mya
amplitude
the numbers in the Richter scale determined by height of a wave
epicenter
the point on earth's surface directly above the focus
focus
the point where the waves originate
subduction
the process in which tectonic plates sink back into the mantle and creates deep- sea trenches
magnitude
the size of seismic waves
Paleomagnetism
the study of the history of Earth's magnetic field
stress
the total force acting on crustal rocks per unit of area
cinder-cone volcano
the type of volcano that is the smallest and has the steepest slopes
ridge push
the weight of a subducting plate helps pull it into a subduction zone in which process?
slab pull
the weight of the subducting plate toward the trench formed at the subduction zone
continental- continental boundary (picture)
what boundary is shown?
the magma is less dense than the surrounding material
what causes magma to rise upward in a mantle plume?
compression
what type of force caused the reverse fault to form?
divergent
what type of volcanism produces the most lava annually?
plastic deformation
when stress builds up past a certain point, called the elastic limit rocks undergo .....
down
which direction does the icy water move
depth of the ocean
which observation was not instrumental in formulating the hypothesesis of sea-floor spreading
Normal fault
which type of fault is shown?
Strike-slip
which type of fault is shown?
reverse fault
which type of fault is shown?
composite
which volcano is shown?