I have read that the edges of the tectonic plates exist at places like: huge mountains and sea trenches, and I wondered if they exist at the mid-oceanic ridges?
$\begingroup$ I think you have things backwards. It's more that things like mountain ranges and ocean trenches exist at plate boundaries, because they are caused by the movement of the plates. Simplistically, two plates moving away from each other create a rift, moving towards each other they produce subduction trenches and mountain ranges. $\endgroup$– jamesqfNov 27, 2016 at 18:25
$\begingroup$ Excellent video: Plate Tectonics Basics 1 $\endgroup$– GimelistNov 27, 2016 at 21:39
The short answer is yes, the edges (boundaries) of tectonic plates do occur at the mid-oceanic ridges, such as the Mid-Atlantic ridge.
There are three types of tectonic plate boundaries:
- Transform Boundaries where the plates slide past each other sideways, such as at the San Andreas Fault.
- Divergent Boundaries where the plates are moving apart, such as the Mid-Atlantic Ridge and the East African Rift.
- Convergent Boundaries where one plate slides beneath the other plate, such as the Andes mountain range & the Japanese island arc.