Questions section 2-3

1. a) A seismograph is a device used to measure and record seismic waves.
b) Seismic waves cause the seismograph's drum to vibrate, while the suspended weight and the pen attached moves very little. Therefore, the pen stays in place while the paper moves, drawing squiggly lines, which then create a seismogram.
c) The stronger earthquake would have waves with a larger amplitude than the smaller earthquake.
2. a) The tiltmeter, creepmeter, laser-ranging devices, and GPS satellites.
b) Tiltmeter: Horizontal and vertical
Creep meter: Horizontal
Laser- ranging device: Horizontal
GPS satellites: Vertical and horizontal
c) That the faults are closer pressed together, increasing earthquake risk.
3. a)
1- to map and detect changes along faults.
2- to monitor changes along faults
3- to try to predict earthquakes
b) They use the reflected wave from the fault, and to record the fault's length and depth.
c) By finding out how much friction there is along the sides of a fault we can estimate how big of an earthquake is going to be made.
Little friction: Little or no earthquake
Moderate friction: Small earthquake
Big friction: Big earthquake