In GEOPHYS310, we learn python. One of the exercises is to plot a station (circle) on a map, with a circle representing some epicentral distance to an earthquake:

import cartopy.crs as ccrs
import matplotlib.pyplot as plt

proj = ccrs.PlateCarree(central_<wbr>longitude=180)

ax1 = plt.subplot(111, projection=proj)
ax1.set_extent([-50, 50, -40, 40], crs=proj)
ax1.stock_img()

ax1.tissot(rad_km=3200, lons=180, lats=10, alpha=0.3)
ax1.plot(0,10,'rv') # note the longitude is now with respect to the central_longitude, but NOT for the tissot circle! 

plt.show()