This demonstration contains two modules that can be accessed from the tabs at the top.

Spatial data: Data points and densities are plotted on an interactive map.

Correlations: A correlation plot is used to investigate possible correlations between the variables in the data.

The data used is that of the USGS earthquake monitor ANSS Comprehensive Earthquake Catalog. To view their website, click on the link below.

USGS

The data used is all earthquakes between 1 Jan 2014 and 31 Dec 2014 of magnitude 4 or greater.

Download the map

The density lines are based on the points included in the map dimensions. When the map dimensions change, the density plots are re drawn for the selected map.

Download the map

For this plot, 5 000 random earthquikes are selected and their only their data are used.

Some information may be lost due to the limit of only including earthquakes of magnitude 4 and higher.

The diagonal plots give a density plot of each variable. The bottom left triangle plots the indivicual variables and the right triangle gives the correlations between the variables.

Below is a brief description of the fields in the plot:

depth: Depth of the event in kilometers

mag: The magnitude for the event.

gap: The largest azimuthal gap between azimuthally adjacent stations (in degrees). In general, the smaller this number, the more reliable is the calculated horizontal position of the earthquake.

dmin: Horizontal distance from the epicenter to the nearest station (in degrees). 1 degree is approximately 111.2 kilometers. In general, the smaller this number, the more reliable is the calculated depth of the earthquake.

rms: The root-mean-square (RMS) travel time residual, in sec, using all weights. This parameter provides a measure of the fit of the observed arrival times to the predicted arrival times for this location. Smaller numbers reflect a better fit of the data. The value is dependent on the accuracy of the velocity model used to compute the earthquake location, the quality weights assigned to the arrival time data, and the procedure used to locate the earthquake.