Notes

Some notes for the research are collected/written here:

Data processing
  • SAC的時間概念
  • Filter中參數p的特性
  • A useful SAC commend: cuterr fillz (used to fill up zeros if there is no data point to cut in demanded time period)
  • IRIS web notes about common rotations in seismology
  • The SAC command interpolate for down-sampling is clearly aliasing once the sampling rate is less than 100 Hz, so the command decimate is always preferred.
  • The unit of the seismograms extracted from seed file is usually in meter, and that downloaded from STP with gain on is in centimeter (count is provided with gain off).
  • NetCDF user's guides [1][2][3]

Waveform simulation
  • The unit of displacement data downloaded from BATS is meter, which is the same with that of SEM synthetics but different from that of FK synthetics. The unit of FK synthetics is centimeter.
  • Since FK uses impulse function instead of step function as moment function, the output of FK is actually velocity seismograms/Green's functions, not displacement.

Instrument

Mathematics

English writing
  • 英文論文寫作時態 [1][2]
  • To + V or To + Ving
  • While & When
  • For the reason - as/because; For this reason - therefore, thus
  • "Due to" is used as an adjective, and "because of" is used as an adverb.

Programming/OS

Machine learning

Miscellaneous
  • The wave-guided effect of subducted plate (with high-frequency content and sustained coda) observed in Taiwan region mainly takes place in a frequency band >3 Hz. (Chen et al., 2013)
  • The evocative "super-eruption" is an informal term referring to volcanic events in which at least 300 km^3 of magma are explosively evacuated from a subsurface magma chamber (Sparks et al. 2005). Any volcanic system that has produced a super-eruption is consequently dubbed a "super-volcano".
  • Characteristics of magma
  • Temperature of magmas (in Celsius): Basaltic magma - 1000-1200, Andesitic magma - 800-1000, rhyolitic magma - 650-800. 
  • Density of magmas (in g/cm^3): Basaltic magma - 2.65-2.80, Andesitic magma - 2.45-2.50, rhyolitic magma - 2.18-2.25
  • Terminology aliases between solid Earth (left) and exploration (right) seismology:
  • source time function  |  source wavelet
    epicentral distance  |  offset
    seismogram  |  trace
    station  |  receiver
    seismic event  |  source
    phase  |  event
  • Slowness u(s/deg) ~ u(s/km) * 111.91
  • Rule of Thumb: building natural frequency (s) ~ 1/10 *number of storey
  • Migration in practice
  • Linear vs. Non-linear elasticity


To-buy list
  • Structural geology algorithms: Vectors and tensors
  • An Introduction to the Theory of Seismology (2nd Edn)