User Guide_Spectral Analysis

The input file needed for Sectral Analysis Application is a *.seed file. After selecting a seed file from the episode database, the User has to enter the workspace, click at "Actions", then "Use in Application" and then "Spectral Analysis" as shown in Figure 1.

Figure 1.

The User now needs to seek for the seismic event corresponding to the uploaded seed file. In doing so, the User has to enter the episode seismic catalog and click on "Actions", then "Use in Simple Component" and then "Event Chooser". Then, from the "Event Chooser", select the appropriate event and click on the "run" tab to extract the associated data. The seismic event can be now uploaded for the Spectral Analysis.Alternatively, the User may upload the respective seed file, once he/she has already selected an event from the catalog by the "Event Chooser" service.The User has just to click on the "Event Chooser", then on "Seismic Event" (shown in the green panel at the left bottom of Figure A1) and then select "Actions", "Use in simple component" and "SeedSearch" (steps indicated in the red boxes, Figure A1).  After this process a simple click on the "Run" that will appear on the screen will upload the appropriate seed file, associated with the previously selected seismic event. Now, all data needed is available for the Spectral Analysis application.

Figure A1.

Waveform Processing

The options provided by the waveform viewer are described in Figure 2 (see also "Waveform viewer guide" section within "Visualizations" chapter) : When clicking on one waveform, additional options appear.

Figure 2.

1. The user selects the component(s) that he/she wishes to be displayed on the screen. East-West, North-South, Vertical.
2. Horizontal zooming in-out.
3. Vertical zooming in-out.
4. Undo zooming.
5. Select between phase (start and end point) picking and single point picking.
6. Select between P-wave and S-wave picking.
7. .Undo picking.
8. Horizontal zooming tool. The User may alternatively zoom in-out the waveform by clicking on this small vertical bar and move the mouse left-right.
9. Collapse the details of the waveform.

Picking Phase for Waveform Analysis:

The User has to select "Phase" and "P" options from the fields 5 and 6 of figure 2 for the Vertical component of a station (**Z channel) and "Phase" and "S" options from the fields 5 and 6 of Fgure 2 for one of the Horizontal components of a station (**N or **E channel). Then he/she has to pick the starting and ending point that wishes to use in Spectral Analysis (Figure 3).

Figure 3.

The User may repeat the process for additional vertical or horizontal components of other stations. When the picking is over, the User shall click on the "RUN" (blue button at the top of Figure 4) tab to initiate the waveform analysis. Soon the process will terminate and the Spectral Analysis results are available (Figure 4). Figures are also generated (Figure 5) and can be downloaded in different formats. Similar results are also obtained for the S-Wave analysis.

Figure 4.

Figure 5.