This map helps in visualizing how plate tectonics affects the actual land around us. Click the image to see the full-size version. We see the fabric of the deep seafloor and its relationship to the mid-ocean ridges and transform faults that offset them. We see the tantalizing tracks of volcanic islands, especially in the Pacific, that gave rise to the concept of hotspots. We see the relationship of trenches, where subduction takes place, to the volcanic arcs beyond. And we see the major mountain chains that arise where continents collide.
The yellow lines mark physical features rather than plate boundaries, although these usually coincide. They include the spreading zones on mid-ocean ridges (divergent boundaries), deep-sea trenches (convergent boundaries) and seafloor fracture zones (transform boundaries) that match the boundary lines on the schematic plate boundary map. In addition, yellow lines mark spreading centers in back-arc settings, but not the diffuse areas within converging continents where nothing in particular signifies a plate boundary. The colors correspond to height above sea level (green/yellow/red/brown) and ocean depth (blue).