Complete List of Terms and Definitions for Earthquake terms

Terms Definitions
Major Earthquake 7-7.9
gram the written record
Great M 7.8 or above
after shocks are considered earthquakes too
Rayleigh waves slower then p+s waves
Reverse Fault Formed by compression forces
Secondary Wave S Wave stands for what?
seismograph is an instrument that records earthquake waves
focus The point beneath Earth's surface where rock breaks under stress and causes an earthquake.
Epicenter. Point on Earth's surface directly above the focus.
What wave travels the farthest? Primary wave
epicenter point on Earth's surface directly above an earthquake's focus
crust outermost layer. contains more silicon and aluminum less magnesium and iron
Seisomgraph An instrument used by seismologist to record primary,secondary and surface waves from EQ
fires The San Fransico earthquake in 1906 caused less deaths than did _______.
Richter scale The earlyest measurement of magnitude and is least accurate.
Liquefaction The process by which an earthquake's violent movement suddenly turns loose soil into liquid mud
granitic the upper crust of continents is composed of _______________ rocks
seismometers an instrument that detects how many waves were made by an earthquake
base-isolated building A building mounted on bearings designed to absorb the energy of an earthquake
S-wave second wave that hits the recording stations
magnitude measure of the energy released during an earthquake
Seismic Waves vibrations that travel through Earth carrying the energy released during an earthquake
earthquake cycle a hypothesis that explains successive earthquakes on a fault by a drop in elastic strain after an earthquake and the gradual accumulation of strain leading to the next quake.
How deep underground was the kobe quake? 15 miles
Primary Waves called (P) waves; Push - pull (compressional) (compress-expand) motion; travels through SOLIDS, LIQUIDS, and GASES; greatest velocity of all earthquake waves
Anticline An upward fold in rock formed by compression of earth's crust
The shaking and vibrating fo the earth caused by large and sudden releases of energy that accompany movement, or displacement, of the crust Earthquake
surface waves seismic waves that travel along the Earth's surface
richter magnitude based on seismic waves that travel through Earth.
Earthquake distance. The epicenter is located using the difference in the arrival times between P and S wave recordings, which are related to distance.
surface wave seismic wave that moves rock particles in an up and down backward rolling and side to side motion
normal fault break in rock caused by tension forces
fault trace a surface tear displacement caused by a fault
Lithosphere averages about 100 km thick in this layer
tectonic plates plates that form Earth's crust. They move slowly on earth's mantle
S waves type of seismic wave that moves the ground up and down or side to side
L - Waves an earthquake wave that travels along earth's surface
Circum-Pacific Belt Major belt around the edge of the Pacific Ocean on which most composite volcanoes are located and where many earthquakes occur.
Moment Magnitude Scale What is the rating system that estimates the total energy released by an earthquake?
oceanic-oceanic plates one oceanic plate gets pushes over the other. This is also subduction
Convections Currents the zone in the Mantle where Molten Rock, "Magma" circulates in a certain direction
p waves A type of seismic wave that compresses and expands the ground
S wave a type of seismic wave that moves the ground up and down or side to side
what is elastic strain? energy stored as a change in shape
strike slip fault blocks of rock move sideways on either side of the fault plane. Near where plates scrape against each other
stress a force that acts on an area of rock to change its shape or volume
Ground movement caused by earthquakes can result in ____, ____, and ____. Destroyed buildings, Fissures in soil and rocks, Landslides.
Isoseismal line A line on a map which joins up points of equal intensity, seperating zones of different intensities
wave motion a wave is one or more of a series of movements passing along a surface or through a substance
Why do geologiss now use the moment magnitude scale? Because it can precisely measure earthquake energy for earthquakes of all sizes near or far.
Intermediate Focus (70-300 km)
love waves surface waves
fastest surface wave
move ground side to side producing horizontal motion
False All faults are plate boundaries
method of locating eq eq triangulation
convergent boundary reverse fault: compression forces suddenly force rock upward.What plate boundary does this occur at?
Earthquakes A sudden trembling of the ground
Seismoraph Instrunment that detects and records earthquake
body waves waves that travel below ground
long amplitude, long wavelength, travels slower, produced by deep earthquakes surface waves
Mercalli scale a scale that rates earthquakes according to their intensity and how much damage they cause at a particular place
MMS? the MMS measures earthquakes based on the total energy released by looking at the distance the rock moved, the type of rock, and the seismic waves.
Tsunami A water wave caused by a earthquake,volcanic eruption, or land slide.
Apparent.
Remnant. 		Development of the Plate Tectonics Theory: ________ Polar Wandering - the continents move (confirmed Wegener's theory that the continents moved). _______ Magnetism - rocks can preserve a "fossil" record of the Earth's magnetic field. Earth's Magnetic Field.
Aftershocks: can have more than 1000/day; decrease in frequency over time
footwall the lower wall of an inclined fault
Swarms, Long-range triggering, Jumping Faults Non Conventional Sequences
Compression Stress that squeezes rock until it folds or breaks.
Core the central part of the earth below the mantle
Seismograph function One part stays as stationary as
possible while Earth vibrates:
heavy mass fixed by inertia in
frame that moves with the Earth,
and differences between position
of the frame and the mass are
recorded digitally
What is the depth of shallow-focus earthquakes? 60 km
seismic wave A vibration that travels through Earth carrying the energy released during an earthquake.
Strike-Slip Fault Occurs when the rocks on opposite sides of the fault plane move horizontally past each other due to shearing.
San Andreas, Garlock, SoCal and Bay Area Branches. Official Faults
Convection Current - Current in Earth's mantle that transfers heat in earth's interior and is the driving force for plate tectonics (circular motion)
laser-ranging device uses a laster beam to detech horizontal fault movements.
divergent boundaries when plates move away from one another
R waves Slower, much like water moves (move forward, particles move in an elliptical fashion, vertically)
tension the type of stress that pulls rock apart
seismogram the written lines that show how much or how little the crust has moved
L wave Waves that are the slowest, but their rolling motion causes the most damage. They ripple out from the epicenter of the earthquake.
shear force a force that when an eathquake dose not go inward or outeward but rubes against each other such as a strike-slip fault
shearing Stress that pushes a mass of rock in opposite directions.
Richtor Scale scale that goes up to ten, 1-10 ten being the worse and as the numbers go higher the damage rate increases by a multiple of 10
shadow zone the wide area around the earth on the side opposite an earthquake's focus where neither p-waves nor s-waves are received
Active Tendon System works like the mass dampeners in the roof- sensors notify a computer that the building is moving- then, the computer shifts a large weight to counteract the movement- located in the bottom of the building
San Andreas Fault the boundary of the Pacific and North American Plate
magma movement movemet of magam as in the case of an active volcano, can cause the earth to move
What are the two types of body waves? Primary and Secondary waves
evidence that port royal was MASSIVE 1. long duration, 2. liquefaction, 3. Landslides changed mountain shape, 4. Water fountains- WRONG. its called fountaining james
What occurs when more pressure is applied to a rock than it ca withstand? The rock breaks and elastic rebound occurs.
The captain of a ship tells you that he once experienced a huge tsunami while sailing in the Pacific Ocean several hundred miles from any landmass. You decide that this sounds a little farfetched because tsunami are rarely felt in deep water because they have long wavelengths and low height