Page History
REFERENCES Document Repository
CATEGORY Source Parameter Estimation
KEYWORDS Source parameters, Earthquake spectra
CITATION Please acknowledge use of this application in your work:
IS-EPOS. (2015). Spectral Analysis [Web application]. Retrieved from https://tcs.ah-epos.eu/
Step by Step
After the User adds the Application into his/her personal workspace, the window
...
as shown in Figure 1 appears.
...
The following files are necessary in order to perform the spectral analysis:
- MiniSEED Waveform
- Network Inventory
- Velocity model
...
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.
Inputs for the "Spectral Analysis" application.
The User can upload files which are already available in his/her personal workspace (green filed in Figure 2) after clicking "SELECT FILES" (red filed in Figure 2). However, if User is not in possession of such files, he/she can obtain them from "Data Search" (green filed in Figure 3).
Figure 2. Input data uploading files for the application.
Figure 3. Application input information.
Once all these files are uploaded the waveforms are shown in the screen and are available for elaboration. As depicted in Figure 4, only the vertical channels are shown by default, since the methodology applied in this application uses only P-waves. Nevertheless, the User can make all the channels appear on the window, by ticking the 'N' and 'E' components, below the 'Show channels' (field 1).
Figure 4. Demonstration of waveform processing
...
Waveform Processing
The options provided by the waveform viewer are described in Figure
...
Figure 2.
4. When clicking on one waveform,
...
a detailed waveform window extends.
- The user selects the component(s) that he/she wishes to be displayed on the screen. East-West, North-South, Vertical.
- Horizontal zooming in-out.
- Vertical zooming in-out.
- Undo zooming.
- Select between phase (start and end point) picking and single point picking.
- Select between P-wave and S-wave picking.
- .Undo picking.
- 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.
- 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 4 for the
...
vertical component of a station (**Z channel)
...
and 'Phase
...
' and
...
'S
...
' options from the fields 5 and 6 of
...
...
Figure 4 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
...
5).
NOTE: Although it is not necessary to pick P-wave nor S-wave arrivals in all of the waveforms to run the application, a minimum of 1 pick is required for the application to proceed to the calculations. The number of the seismograms, P-wave phases and S-wave phases picked, are updated each time the User makes a new picking. The User may also load picks from XML file (red filed in Figure 4) rather than processing the waveforms manually.
Figure 5. Phase picking demonstration for S (upper frame) and P (lower frame) waves
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
...
' tab (green button) to initiate the waveform analysis. Soon the process will terminate and the Spectral Analysis results are available (Figure
...
6).
...
Graphs are also generated (Figure
...
7) and can be downloaded in different formats. Similar results are also obtained for the
...
P-Wave analysis.
Figure 4.
Figure 6. Output parameters of the application
Figure 7. An output graph of the application
| Widget Connector | ||
|---|---|---|
|
...
Overview
Content Tools