The Mid-Atlantic Ridge illustrates a divergent plate tectonic boundary. The ridge consists of an undersea mountain range that continues from the southern Atlantic Ocean through the northern Atlantic Ocean. Tensional stress along the crest of the ridge produces troughs, or rift valleys, within the ocean ridges. In addition, fracture zones break up portions of the ridge and extend in some cases to the edges of the continent.
The following images show topography and its relation to this plate tectonic boundary.
Image from the National Geophysical Data Center
Image from the USGS