So tremor sense allows you to feel vibrations through connected liquid or solid matter.

Earth elementals have earth glide which allows them to freely travel through earth (stone, dirt, ... (even lava if they have resistance or immunity to fire)).

How does it know what kind of substance it is about to travel through? How does it detect voids (not tunnels which you could rule feeling the vibration of air flow in the tunnel) or that there is a buried chest its about to run into? Or some other hazard that is in its path that it might want to avoid but "doesnt know about" because its not moving.