Fig. 8
From: Local earthquake response on the submarine communication cable in the northern South China Sea
(a) P-color map after stack. (b) P-color map after stack and DWT. Discrete wavelet transform eliminate most of the noise and retain the P and S waveform according to the different frequency bands and threshold parameter. The DWT result shows the malpractice of P wave elimination in the case that the wave amplitude is equivalent to the noise.
