What’s the point of having data split over different colours/coasts? Rather had more info on the circles’ sizes, but ok

Edit: should have added a thank you note for op, because sounds like I critize them but I’m not

Is the reason for the East/West coast disparity the tectonic plates? I imagine (at least along the Juan de Fuca subduction zone) that the interaction makes the terrain more rugged compared to the geologically more stable Atlantic coast.