Composition

The application Seismic Catalog Recalculation is underneath composed of elements of three other applications - Localization, Spectral Analysis and Catalog Editor. The results of Localization and Spectral Analysis are used to generate parameters for an event, which is later updated or added to the input catalog with the use of the Catalog Editor application. For this reason, the inputs and outputs of the application are a composition of the three applications' inputs and outputs. 

Input file specification

The application requires four types of files (one file per each type) - see Figure 1:

• Catalog - a seismic catalog of events in EPISODES Platform Matlab-based format.
• Miniseed Waveform (or any subtype) containing seismograms on which an event is recorded - either an event already contained in the catalog, for which we want to update the parameters, or a new event that should be added to the catalog.
• Network inventory, either in XML or datalessSEED format
• Velocity model in EPISODES Platform GDF format.

All of the files can be found within the platform's Episodes data (see AH Episodes quick start guide), uploaded to the workspace or obtained with one of Converters.

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Figure 1. Application input files specification

Filling form values

The application form is composed of two parts - picking the P and/or S wave arrivals (marked with (1) in Figure 2) and setting the event details (marked with (2) and (3) in Figure 2).

The required picks are at least three points with P wave arrival and at least one pick for P and/or S wave. The picked points are used for the Localization application and the phases for the Spectral Analysis application (see the first section of this guide). For more information about the functionality related to picking wave arrivals see the Seismogram picking tool user guide.

The Event ID (marked with (2) in Figure 2) identifies the event in the catalog - if the ID already existed in the input catalog, the event details will be replaced in the resulting catalog, otherwise, an event will be added to the resulting catalog (see Catalog Editor user guide for more details on event ID specification). The event coordinates will be passed as parameter to the Localization application (see Localization user guide). Both values can be read from an existing catalog or other files containing event location and ID.

Figure 2. Application form with values filled

Produced output

The main output of the application is a seismic catalog based on the input catalog modified with event details provided by the Localization and Spectral Analysis. The result file will have the same name as the input with additional _mod suffix (e.g., if the input catalog file was called sample_catalog.mat, the result catalog will be named sample_catalog_mod.mat), and it will be visualized within the application outputs. Depending on the configuration, the new catalog will either contain a new event or have updated values for a selected event (see previous section). An output catalog is shown in Figure 3 and Figure 4. Note, that the modified/added event may contain additional properties, that were not present in the input catalog (e.g. M0 and Mw values visible in Figure 4)

Figure 3. Output catalog file - basic view

Figure 4. Output catalog - file contents view with new event marked

Additionally, the application provides also partial results from the Localization and Spectral Analysis applications for more in-depth verification. These are available after opening the collapsible panels below the catalog view (see Figure 5 and Figure 6). Latitude, Longitude and Depth from the Maximum-likelihood solution of Localization application (see Figure 5) are inserted as, respectively Latitude, Longitude and Depth of the event in the catalog (compare Figure 4). The Seismic moment, Seismic energy and Moment magnitude from the Spectral analysis Result summary (see Figure 6) are insterted as, respectively, M0, E and Mw of the event in the catalog (compare Figure 4).

For more details on interpretation of the Localization and Spectral analysis, see the respective user guides: Localization user guide and Spectral Analysis user guide

Figure 5. Results of the Localization part of the application

Figure 6. Results of the Spectral Analysis part of the application.

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