For the analysis we choose a rectangle with coordinates:
lower left longitude: -80.131640; lower left latitude: -56.006573; upper right longitude: -65.805468; upper right latitude: -16.608122. Magnitude range: from 5 to 10. Date & Time(UTC): from 1960-01-01T00:00 to 2015-09-21T09:48.
Results from these selecting options from the database shown in Figure 1. Places of earthquakes are marked with orange points.
Change the layer legend "EarthQuakesSquare" as shown in Figure 3. The number of earthquakes in the layer "EarthQuakesSquare" is contained in the attribute called "AggregValueGIS".
- Select the name of the layer "EarthQuakesSquare" in the "Editable Layer" list.
- Open the attribute table using the menu item "Edit->Open attribute table".
- Create a new attribute for instance called "Count". It will be used to create 2.5D columns. Their height will be calculated in meters above ground level depending on the number of earthquakes in each square. Therefore, this attribute must be created using the formula shown in Figure 4.
Learn how to create a heatmap, reading here: "Heatmap and Interpolation in OpenWebGIS (very easy and interestingly)".
An interactive heat map is available here: MAP 3.
The result of your actions will be as shown in Figure 9 in the video below, and on and interactive map available at the link here: MAP 4
For the analysis we choose the square number 54 (highlighted in Figure 10). In the options function "Time and matrix analysis" specify the length of the window equal to 28. The result is shown in Figure 11.
To create the trend take the first principle component, for periodic let`s take the second principal component. The result is shown in Figure 12.