1. Department of Earth Sciences KFUPM Introduction to Seismology Earthquake Statistics (pp. 371-396) Introduction to Seismology-KFUPM Ali Oncel [email_address]
3. You have learned how to pinpoint the location of an earthquake by measuring the speed of seismic waves radiating away from the focus of the earthquake . Now, we can determine an earthquake's magnitude by measuring the strength of ground shaking as you did for global earthquakes . Learn how to do both these things by visiting the virtual earthquake web page. http://www.sciencecourseware.org/VirtualEarthquake/VQuakeExecute.html and completing the exercise . It should take you about 30 minutes . Turn in your certificate of completion at the beginning of class on Monday, 26 March. Homework: VIRTUAL SEISMOLOGY Introduction to Seismology-KFUPM
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11. DESIRABLE PROPERTIES OF EARTHQUAKE CATALOGUES Homogeneity: if parameters are redetermined then uniform redetermination magnitudes determined uniformly or calibrated against each other intensity values on same scale all parameters to known accuracy, e.g. hypocentres Complete: ideally complete down to small magnitudes, but certainly of known completeness Duration: catalogue to cover a long time span, ideally greater than the largest return periods Source material: known and referenced if there are multiple sources for some earthquakes and parameters are not uniformly re-determined then a stated hierarchy of preferences amongst sources Computer readable: simple format Introduction to Seismology-KFUPM
12. COMPLETENESS Depends on data availability. The usual and obvious bias is against small shocks in the earlier years. During the instrumental era it is a function of network density and detection threshold. In the pre-instrumental era (historical) it is a function of population density, culture and survival rate of documents. Introduction to Seismology-KFUPM