Evidence for volcanic activity on the seaflor associated with iceland extends both to the east and to the west of iceland. this is called the "trail" of the mantle plume. how does the bathymetry (shape of the seafloor) east and west of iceland vary from the seafloor to the north and south of these areas? a. there are deep ocean trenches, indicating the presence of subduction zones. b.there are abundant mid-ocean ridges. c.the area is smoother and flatter from the abundant lava flows. d.there is no noticable difference.