Why are subduction zones curved?

One of the most prominent features when looking on the large-scale topography of Earth are subduction zones. Since I have often wondered why they usually are arc-shaped I decided to delve a bit into the topic and share my findings in this post. It is mainly from a perspective of a geometrical model proposed in  “Why…

The Ruminarian…

I’m going to deviate from the volcano topic for a bit… not too far, but I think that a discussion of the dynamics is important to gain an appreciation for the forces at work. Again, the standard caveat: I’m not a geologist. There are actual geologists who lurk and pass through here. If I mess…