To a/b, or not to a/b
The a/b value is sometimes used as a measure of seismic hazard but there are some common mistakes made with this analysis and interpretation. What is a/b? The Gutenberg-Richter distribution is a statistical model that describes a log-linear relationship between the number of events, N, exceeding magnitude, M. log10 N = a – bM At N […]
Frequency-magnitude chart anatomy
When you are using the frequency-magnitude chart, it can be easy to forget it is log scale and this can distort a few things. Consider the chart below; have you ever thought the Gutenberg-Richter distribution doesn’t look right? Think it isn’t matching the large events very well? The Gutenberg-Richter distribution is a statistical model of […]
Event tags and comments
There are many reasons you might want to store a short snippet of text associated with an event. There are two ways to do this in mXrap; event tags and event comments. Event tags can be used to group events into categories. Example tags might be ‘suspected blast’, ‘damage occurred’, ‘suspect location’, ‘outlier’ or ‘likely […]
Using selections in the event filter
You can use selections to filter events in General Analysis. This gives you a lot more freedom than being restricted to the traditional min/max range filters. Follow the steps below to see how you can use this feature to plot the frequency-magnitude chart for events occurring during periods of high apparent stress. You can also […]
Seismicity Versus Distance to Surveys – New Charts in General Analysis
The distance to survey filter has been around for a while but now we have added a couple of new charts to further investigate the relationship between seismicity and your input surveys. The charts have been added to the General Analysis application, under the Charts menu – look for Distance to Surveys. There is a […]