No major landforms have appeared recently in human timescales. Landform evolution operates on geological time (10³–10⁷ years). Current changes are incremental:
Humans now move more sediment than all natural processes combined (~30 Gt/yr vs. ~21 Gt/yr). Mine spoil heaps, artificial islands (Palm Jumeirah, Hong Kong Airport), reservoir deltas, and landfills are technogenic landforms—geologically instant, but not "natural" major landforms.
True major landforms—mountain ranges, continental shelves, ocean basins, cratonic shields—require tectonic forces and deep time. We're witnesses, not architects.