KYTL+2.4

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Vocabulary

 * Creep Meters**- can measure the movement along a slip-strike fault
 * Laser-Ranging Devices**- a device that measures changes with a laser beam and a reflector
 * Tiltmeter**- measures tilting of the ground; works kind of like a carpenter's level
 * Satellite Monitor**- uses radar to take pictures of faults

Devices that Monitor Faults

 * geologists use instruments to measure stress and deformation in the crust
 * Creep Meters
 * uses a wire stretched across a fault to measure horizontal movement along the fault
 * one side of fault-wire anchored to post
 * on other side, wire is attached to weight that slides if fault moves
 * Laser-Ranging Devices
 * uses a laser beam to discover tiny fault movements
 * calculates changes in time needed for the laser beam to travel to a reflector and bounce back
 * can detect any difference in change through the beam
 * Tiltmeters
 * measures tilting of the ground
 * includes 2 bulbs filled with liquid and is connected to/by a hollow tube
 * if land rises/falls the liquid will flow from one bulb to another
 * in bulb is a measuring scale that measures the depth of liquid in bulb
 * Satellite Monitors
 * satellite bounces radio waves off the ground
 * satellite records the echos of the waves that bounced back into space
 * amount of time it took for the radio waves to make their way back and forth is the precise measurements of distance to ground
 * geologists can detect small changes in elevation

Monitoring Risk in the United States

 * geologist can't predict when and where the earthquake will strike
 * but geologists **__can__** determine earthquake risk by locating where faults are active and where past earthquakes have occurred
 * highest risk areas in the United States:
 * Pacific Coast:
 * California
 * Washington
 * Alaska

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Diagram(s)