User Guide SSH

The only data required for Stationary Seismic Hazard  (SSH )application is a catalog containing seismic events ('_catalog.mat' is appended in the filenames contain such catalogs). The User goes to his/hers personal workspace and clicks on a seismic events catalog, that is already uploaded (see section ..... eg data handling).

For using a selected catalog for SSH, the User shall click on the "Actions" tab and then select consecutively, "USE IN APPLICATION" and "Source size distribution function", as shown in figure 1. 

Figure 1.

Once the service has been selected the User is requested to fulfill some fields with parameter values needed for the SSH analysis (figure 2). These parameters are:

Using seismic catalog: A catalog has been already uploaded since the previous step, however, the User has the chance to select a different dataset, either from another episode or the any dataset after performing some processing/ filtering.

Select Magnitude column: The user may click on the small arrow in the respective tab in order to chose among different magnitude scales, in the cases where they are available (e.g. ML, Mw, etc).

In any case the magnitude range (minimum and maximum magnitude assigned in the catalog) is shown in the screen (M range)

Mmin: The User now is requested to chose the minimum magnitude (completeness level of the catalog). This can be done in two ways. The first is to type a single magnitude value in the empty box, possibly after he/she has performed an individual analysis (see MCE service). The second is to graphically select the minimum magnitude from the Normal or the Cumulative histograms, which are available after clicking on the respective tabs. In both cases there is option to alter the step of the histogram's bars and to select between linear and logarithmic Y-axis for the plotting.

Time unit: There are 3 options for this parameter, which are shown after clicking on the small arrow in the box: Day, Month, Year. The time unit will be stored and all the calculations hereinafter will be performed according to this unit.

Magnitude distribution estimation method: Four different methods are available in the IS-EPOS platform: The Unbounded Gutenberg-Richter, the Upper-bounded Gutenberg-Richter, the unbounded non-parametric and the Upper-bounded non parametric estimations. To select one of the aforementioned methods of analysis, the User has to click on the arrow in the respective box.

Magnitude iteration: Here the User is requested to enter minimum ('Start' tab), maximum ('End' tab) and step ('Step' tab) values of the magnitude. After that the platform will evaluate the distribution parameters as a function of magnitude.

After selecting all the parameters needed the User may click on the run button, for the calculation process to be initiated.

Figure 2.

The results of the process include a report with parameters values selected by the user and estimated by the application and two figures, one plotting the PDF of the distribution as a function of magnitude and another one plotting the CDF of the distribution as a function of magnitude (figures 3 and 4):

The SSH parameters calculated and shown are depended on the Magnitude distribution estimation method selected. They are summarized on Table 1.

Table 1.

figure 3.

figure 4.

The figures provide the options of selecting among linear, spline and scatter plot, linear logarithmic scale, zooming and saving as .pdf, .svg, .jpeg or .png formats.

The necessary parameters for SSH analysis are now estimated ("ssh_params.mat" at figure 5) and they are ready to be used in Hazard parameters estimation. This can be done after clicking on the "Actions" tab and then selecting "USE IN APPLICATIONS" field. Three such parameters are available in the IS-EPOS platform: Exceedance Probability, Maximum Credible Magnitude and Mean Return Period.

figure 5.

Exceedance Probability: