ERTH 2415 Lecture Notes - Lecture 5: Inverted Pendulum, Nomogram, North South Mrt Line
27 Mar 2018
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Document Summary
Faults: fault: fracture across which two blocks of rock move relative to each other, faults found in several tectonic environments prone to large earthquakes, megathrust faults, transform faults, faults are usually complex zones of breakage. Irregular surface: rough and interlocking rocks, special minerals, major faults extend several kms in the subsurface, most faults do not have a surface expression. Waves: wave: oscillation in space and time travelling away from an initial disturbance, seismic waves: waves caused by the release of energy in the earth. How are seismic waves recorded: seismometer: sensor that detects ground motions, seismograph: an instrument that records ground motions, seismogram: paper record or digital file with data describing ground motions. Zhang heng(78 - 139 a. d. : emperor"s chief astrologer, responsible for detecting signs of bad government which were indicated by earthquakes. Modern seismograph station: quiet environment, good contact with bedrock, three seismometers detect the three components of ground motion, east - west, north - south, up - down.
