Hi Cahya,
As per my understanding, you are trying to plot a beachball data using ‘mmap’, but you observed that the plot is wrong. You are looking for the way to specify the spheroid for plotting in the right latitude and longitude.
- Get the focal mechanism data: Ensure that your data is accurate and in the correct format. The data should include parameters like strike, dip, and rake.
- Make SVG files for each focal mechanism: This can be a bit tedious, but it’s necessary for visualizing each mechanism on your map.
- Load the data in QGIS or your preffered GIS software: You can plot a single focal mechanism by clicking the button on the map toolbar, and then double-clicking on the earthquake location on the map. This will plot on the map, and you can drag it to the location where you want it.
- Change the Style settings to find the icon paths: This steps involves linking your SVG files to the data points on your map.
- Set min/max map scale limits, change icon size by map scale, etc. These adjustments can help improve the readability of your map.
Remember, the location of the beachball plot represents the mean location of energy release during an earthquake, not necessarily the location where slip initiated on a fault.
Please refer to the following references to know more about
- Plotting focal mechanism ‘beachball’ in QGIS: https://rocksandwater.net/blog/2017/09/plot-focal-mechs-in-qgis/
- Visualizing 3D Focal mechanism(beach ball) in QGIS: https://geoscience.blog/visualizing-3d-focal-mechanism-beach-ball-in-qgis/
I hope this helps.
