zmap a tool for analyses of seismicity patterns typical applications ...

Save new mat-file: At this point it is time to save the culled catalog in a mat-file by
clicking on the Save selected Catalog (mat) button in the Catalog menu of the
seismicity map. It is a good idea, but not necessary, to now reload this new catalog.
Inspecting the catalog: From the ZTools menu select Histograms, then select Depth.
The resulting Figure 1.5 shows that there must be an erroneously deep event in the data
and
Figure 1.5: Histogram as a function of depth.
that there exists a minimum at 35 km depth, which might be the separation between the
crustal and the intraslab activity. Next, select Hour of Day from the Histogram button in
Figure 1.6: The absence of smokestacks at certain day hours suggests there are few or no explosions
the ZTools menu. The resulting Figure 1.6 shows that the data are not contaminated by
explosions (or at least not much) because the reporting is uniform through day and night.
Finally, check out the distribution as a function of magnitude by plotting the appropriate
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