Synthetic Seismograms

0 m depth indicates the transition to the time when the channel was active, more than 

Wet Bulk P-Wave Attenu-Carbonate Oxygen Density Velocity ation Content Isotopes P 

000 years ago. Only terrigenous turbidites causing strong reflections below 6 m depth were deposited. 

---

However, the details of the velocity structure beneath the lid are not well constrained. Figure 3d shows that the minimum velocity at these depths can range from 4.35 to 4.45 km s and has only a small effect on the synthetic fits to the observed waveforms at 2106 km distance, but increasing the minimum velocity to 4.5 km s or greater results in an unacceptably early highermode arrival for the synthetic seismograms compared with the observed seismograms at this distance. 

Fig. 6. Three-component waveform fits at three distance ranges for synthetic seismograms (dotted line) computed from the southern African velocity model of Priestley (1999) and the observed seismograms (continuous lines). The Love and Rayleigh wave seismograms are fitted with the same velocity model, implying that at least the upper-mantle lid is isotropic. Event 860718 is event 2, Figure 1 910724 is event 7, Figure 1 and 940818 is event 8, Figure 1.

Mendel J.M., Nahi N.E., Chan M., 1979. Synthetic seismograms using the state space approach. Geophysics 44 880-895... 

Finally, we calculate synthetic seismograms for this model to show the effect of fast and slow P waves as a function of permeability. Each trace of Figure 6 represents different permeability. The waveforms were produced for a peak source frequency of 300 Hz. At this frequency, both waves are sensitive to permeability. For frequencies <100 Hz (see Figure 5), as permeability decreases, the amplitude of the fast P wave remains about the same, but slow wave amplitude decreases as permeability decreases. 

When an initial estimate of the moment-tensor elements has been obtained by solving the inverse problem in Eq. 11, the change in the synthetic seismograms with respect to small changes in source location and the moment-tensor elements can be written as... 

By iteratively updating the moment-tensor and centroid estimates, as well as the corresponding synthetic seismograms and kernels, and inverting the residual signal for additional perturbations in the source parameters, an optimal estimate of the point-source parameters is obtained. 

Olsen KB (1994) Simulation of three-dimensional wave propagation in the Salt Lake basin. PhD thesis. University of Utah, Salt Lake City Olsen KB, Mayhew JE (2010) Gexxlntss-of-tit eriteria for broadband synthetic seismograms, with application to the 2008 5.4 Chino Hills, California, e arthquake. 

In the RCMT computation process, the source excitation has been always computed in PREM (Dziewonski et al. 1981). Synthetic seismograms... 

---