Faults:  breaks in the earth's lithosphere, with movement along the break
    faults are planes, not lines.  some faults vertical, some shallow tilted, some horizontal
    movement directions:  fault blocks move sideways, up (most deadly), or down
    active faults versus inactive faults: millions of dead faults in Washington
    seismic faults (fast movement) versus aseismic faults (slow movement, no quakes)
    ***plate boundaries are made of one or more giant faults separating plates
    ***most active faults are NEAR plate boundaries but are NOT plate boundaries
    ***only a few faults are plate boundaries; most faults are within plates, near edges

Earthquake:  ground shaking,  also known as seisms or temblors
    moving blocks along fault is NOT the same as ground shaking (earthquake)
    sources of earthquakes:  rapid fault movement (99%), magma, landslides, cave collapse
        ***fast movement of blocks along a fault PRODUCES/CAUSES ground shaking (quake)
    location:  focus/hypocenter (location of quake on fault), epicenter (spot above quake)
    types of earthquake/seismic activity associated with fault movement:
       pre-seismic activity:  slow ground motion, changing water wells, radon gas bubbles
       foreshocks:  quakes found on same fault plane as main shock, mins--hours before
       main shock:  ground motion, enhanced ground motion, ground rupture, tsunami
       aftershocks:   usually smaller than main shock; fault plane found from aftershocks
    size/magnitude of earthquake: 3 common scales/indices/measures of quake size
       Mercalli: based on amount of damage and human response (no instrument)
       Richter:  based on amount of ground shaking as measured by seismograph
       Moment: based on size of fault that moved and amount of movement on fault

Seismic waves:  earthquake waves that travel through the Earth or on the surface
    seismic waves produced by fast fault block movement; movement causes waves
       P-waves or sound waves:  primary waves, arrive first, pass through all materials
       S-waves or shear waves: secondary waves, arrive second, pass through solids only
       Surface Waves:  only travel on the earth's surface, causes most ground shaking
    recording instruments = seismographs/meters, modern machines developed in 1930's
    interpretation of seismograms (= quake record), recognizing types of seismic waves

Seismicity:  earthquakes around the Earth
    most earthquakes along/near plate boundaries, where you find many active large faults
    a few earthquakes in plate interiors, like Missouri; old faults and new earthquakes
    Washington earthquakes; subduction zone quakes, crustal quakes, volcano quakes
    the Seattle fault and giant pre-historic earthquakes in Seattle

Earthquakes and People:  what causes fast fault movement/quakes? don't really know
    old idea:  stress buildup along fault, "sticky hands of science":  WRONG
        faults are not sticky, they are well lubricated by ground up pasty goop
    earthquakes are basically random; ± unpredictable (the car wreck model)
        description  of quakes: YES (frequency, probability...).  prediction  of quakes: NO
        failed attempts at prediction:  seismic gap method and the history of earthquakes
        more failures:  well levels, radon, foreshocks, animals, cats and cows, psychics, etc.
 earthquake preparedness; physical preparations, mental preparations.
 

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