Update: 10/20/2010
WinQuake was written to view and analyze Public Seismic Network (PSN), Princeton Earth Physics Project (PEPP), SAC Binary, GSE2.0, Lamont AH (XDR), and Standard for the Exchange of Earthquake Data (SEED) volumes available on the Internet.
New features include:
- Improved SAC Binary Support
- Lamont AH (XDR) Event File Support (Read Only)
- Export of Raw FFT Data
After downloading the self-extracting WinQuake setup program, execute the program using Windows Explorer. You can also execute the setup program by opening a DOS box and typing the name of the WinQuake setup program.
During the installation, enter the requested information in the dialog boxes. When you want to go to the next dialog box click the Next button. When all of the information is entered, the setup program will install the program in the directory you selected.
The Open File dialog box is used to open event files. After opening an event file you can zoom into a section of the seismogram by using the mouse or the X-Scale dialog box. To use the mouse, do the following:
To zoom out, select the Reset item under the View menu, press the RST toolbar icon, or use the X-Scale dialog box.
WinQuake calculates distances between the event and the recording station by the user moving the P and S markers to the beginning of the P and S waves on the seismogram. You must first enable distance and magnitude calculation by selecting the Distance/Magnitude item under the Calculate menu. See How WinQuake Calculates Distance for more information. If the magnitude correction factor is known for the sensor, WinQuake will display the magnitude of the event. See How WinQuake Calculates Magnitude for more information.
After picking the P and S waves, other phases like PP, PcP, SS, SSS etc, can be viewed by selecting the Phases item under the View menu, or using the phase display toolbar icon. The Phase Control dialog box is used to add or remove phases that will be displayed when this feature is enabled. With the Event Location Map Window (see below), and three or more P and S picks from different stations, the user can locate an event.
The program can locate the P and S markers if the event location and time of origin are known. If these fields are filled in, using the Event Report processing or the Event Information dialog box, the program will use the currently selected travel-time tables and depth to calculate the location of the P and S markers. Too activate this feature, use the P-S Location menu item under the Calculate menu or the LOC icon on the toolbar.
WinQuake can be used to locate an event using the Location Map Window. A typical Location Map Window looks like this. After opening one or more event files and picking the P and S phase, a map can be drawn showing the stations with a distance circle. This can be used, if you have good P and S picks, to locate the event. Where the circles overlap, or come near each other, is where the event occurred.
To open a Location Map window, click on the map tool bar icon next to the RST (Reset) icon or use the "View/Locate Event" menu item. After opening a map window, you use the Zoom menu to zoom in and out. To move the globe around, double click on a point on the globe. This will move the map so that this point is now centered in the window.
Stations are marked with a triangle and a small square marks the location of the event, if the event location is known. A small + marks the center point of the graph. On the left side of the window, the cursor's location is displayed as well as the azimuth and distance from the center point. Under the Cursor location is the Station color codes. The station markers and distance circles are drawn with these colors. Under the Station information is the event information, if the event information is known.
After locating an event using three or more event windows, an event report can be created using the mouse. To do this, move the mouse to event location and right click. This will open a floating menu bar. Select the Make Event Report menu item. WinQuake will now make an event report based on the P and S picks in the event window. The time of origin and the magnitude are calculated by averaging the data in each event window. The depth comes from the current selected P and S travel-time table depth selected in the Travel-Time Tables dialog box. The event location will be based on the location of the mouse at the time the report is created. After calculating the information, WinQuake will open the Update Event Report dialog box. This dialog box will display the report information and if the user press the Update all Event Windows button, all of the event windows will be updated with the new report information.
When using this Window, make sure you are viewing event files for only one event. If you have event file windows open for more then one event you will have problems location the event.
To display a frequency spectrum of an event file, use the Full FFT or the View FFT items under the Calculate menu, or use one of the two FFT toolbar icons. This will open another window displaying a frequency spectrum of the complete data set, if you use the Full FFT menu or icon, or do a FFT only on the data set being viewed, if the View FFT menu or icon is used. A typical FFT Window looks like this.
The amplitude data of the FFT can be displayed either logarithmically or linearly by using the Log-Y item under the Option menu. The Options menu can also be used to control the displaying of the X or Y grids, and turn the FFT Window's title bar on or off.
After you create a FFT graph window you can apply digital filters to the data set. Note: The IIR Filter (see below) produces a more accurate filter then using the FFT method. Instead of using the FFT window to filter the time domain data set, the user should use IIR filtering.
Since filters are applied to the complete data set, filtering can only be done when the Full FFT menu or icon is used. When the View FFT menu or icon is used, the filter icons and menu items under the Calculate menu will be disabled.
The following filters can be applied to the data set:
After applying one or more filters to the data set, you can convert the FFT information back to the time domain (normal event graph) by selecting the Time Domain item under the Calculate menu, or by using the Time Domain icon in the toolbar. When WinQuake finishes performing the reverse FFT, the event data window used to create the FFT Window will be updated with the newly filter data set.
When the "FFT View" feature is used, and the Auto FFT Display item is checked in the Event Window's Calculate menu, you can view a new FFT of the viewed data set as you scroll through the data using the vertical scrollbar.
The user can zoom in and display one decade at a time by using the magnifying glass toolbar icon or using the mouse and clicking in area you want to zoom into.
This method of filtering is done directly to the data set and produces a more accurate filter then the FFT data set filtering (see above). Unlike the FFT data set filtering, there is no need to do an FFT before and after filtering the data. The process of doing the FFT causes small inaccuracies when the frequency spectrum data is converted back to the time domain.
To apply an IIR lowpass or highpass filter to the data set, open the Time Domain Filtering dialog box using the Calculate / Time Domain Filter menu items or press the "F" toolbar icon. After selecting the filter type, cutoff frequency and number of poles, press the Apply Now button. The Undo Filter button can be used to undo the previous filter applied to the data set. See the Time Domain Filtering dialog box for more information.
WinQuake Version 3.1.2 and above supports displaying the event and/or station location in Google Earth. For this feature to work you must install Google Earth and have a Internet connection so Google can access the online map database. The Google Earth feature is located in various menu and dialog boxes within WinQuake. They are:
- Main Menu under View / Google Earth
- Event Report Dialog Box
- Location Map - Place mouse cursor on location, right click select Google Earth
