Perspectives

Many different interesting questions can be explored using this dataset. One of the most fundamental in terms of earthquake physics is the question of scaling: does the same thing happen in tiny events as in the large events which capture public attention. However, this sequence also offers a view into the relationship of mainshocks and aftershocks for small earthquakes. Normally, only a few aftershocks with magnitudes between 0.5 and 3.5 would make it into the catalog. For the Orinda MS, more than 4000 aftershocks have been recorded and are available for analysis. It should be possible to map their locations with respect to the MS, and perhaps determine its rupture surface independently. Other perspectives include investigations of the effects of path attenuation on the frequency content of small events.

Figure 13.14: Magnitude calibration. Gray dots show the events from the Orinda sequence which are in the NCSN catalog. A least-squares regression (line) allows $M_{L}$ to be determined for the many small events.
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