Sonar effect trouble

Hello denizens of, I have come back with yet another question.

I was asked to create inside of Unity a sort of sonar effect, that hugs the ground topography and emanates from where the marker, in this case a stone mesh, is placed.

Here is a drawing of what I mean to assist in clarity -

I wanted to see if anyone would be able to give me advice on how they would approach this effect. I know how to create the waves as asked, it is the hugging the ground part that is intimidating me, with this stone capable of being placed on multiple different areas around the map. (The project, as I understand it, is roughly akin to the game Civilization, and has the same camera angle).

Thank you in advance for any help!