Well, I think radio waves is certainly a good place to start. But it might be might be more striking if used in combination with a displacement map effect.
Try making a comp with the map of the earthquake zone and a plain solid. Then apply Effect > Generate > Radio Waves to the solid layer. Adjust the settings until you get a propagation pattern you like, then precompose that solid layer, being sure to click the radio box for “move all attributes into the new composition.”
Then go back to your original comp, select your hero map layer, and use Effect > Distort > Displacement Map. Select the precomp layer as your “Displacement Map Layer,” select “stretch map to fit,” and try a RAM preview. You’ll see the effect the waves are having on your map layer. You can then go into the precomp to adjust the settings on the wave to suit your taste.
Hope that works for you.
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