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…

Mount Shasta or Úytaahkoo, the “White Mountain”

Volcanic activity in North America is surprisingly infrequent. In spite of there being no less than 255 volcanoes or volcanic features such as maars or volcanic fields listed for California (20), Oregon (65), Washington (21) and British Columbia (149), situated on or adjacent to the Cascades Range and above the subduction zone where the last…