Park Seismic LLC, Shelton, Connecticut, Tel: 347-860-1223, Fax: 203-513-2056, Email: email@example.com
|ParkSEIS | Generation of 1D S-Velocity (Vs) Profile
1. Importing Input Data [Dispersion Curve File (*.dc)]
|2. Run (Automatic 1-D Vs Profile)
It is often beneficial to attempt one or more passes of inversion process through a manual searching process followed by
another automatic inversion process. This can often lead to finding a profile whose M0 curve matches the measured curve
even better and/or a profile that appears more realistic. The module displaying the inversion output of 1-D Vs profile has all
the functions ready for this purpose. For example, the individual layer can be changed in its velocity and thickness by the
click-and-drag motion of mouse toward either horizontal (velocity) or vertical (thickness) direction. Then, the displayed model
dispersion curve [*(Model).DC] will be accordingly updated with the new match (%) indicated in the top title bar of the display
The example below illustrates that several layers are changed in velocity (Vs) by using the click-and-drag motions of mouse
so that the overall profile may look more realistic. The top title bar shows the match improved indicating the manual update
|3. Run (Optional Further Manual Inversion)
Now, because the "initial" velocity model has been slightly updated, another automatic inversion may find "further improved"
velocity profile. So, it is now attempted to run it again by selecting "Inversion" tab on the menu panel, and then clicking "RUN"
button as illustrated below. The new match (85.33 %) now shows it little improved. This is usually the case if the new
automatic inversion process could not find another model significantly different from current one that maintains comparable or
improved match in M0 curves.
Then, it is worthwhile trying to introduce another degree of freedom in the process by choosing the option of "Variable max.
depths" as illustrated below. It will then execute the automatic inversion process for as many different depths models as
selected (e.g., 10) that are created by either contracting (< 100 %) or stretching (> 100%) current velocity model. The
example illustrated below indicates that the process will examine ten (10) different initial models within 75% - 125% scale of
current velocity model. From the search with all these different models, the program will show at the end the model that has
the best (i.e., highest) match.
Click "Run" button to perform this "Variable max. depths" inversion. After a while, the final solution of velocity model will be
displayed. The example below indicates the match improved noticeable from 85.33% to 89.34%. Above all, the profile looks
|Now, it may be the time to save it as the final solution.
|Output 1D Shear-Wave Velocity (Vs) Profile Displayed Below