Waltemath described one of the proposed moons as being 1,030,000 km (640,000 mi) from Earth, with a diameter of 700 km (430 mi), a 119-day orbital period, and a 177-day synodic period.
A subduction zone is formed at a convergent plate boundary when one or both of the tectonic plates is composed of oceanic crust. The denser plate, made of oceanic crust, is subducted underneath the less dense plate, which can be either continental or oceanic crust.s a result of pressure, friction, and plate material melting in the mantle, earthquakes and volcanoes are common near convergent boundaries. When two plates move towards one another, they form either a subduction zone or a continental collision. This depends on the nature of the plates involved.
Ridges. Opposite of a convergent boundary, a divergent boundary is formed by the spreading of a tectonic plate. This process feeds magma to the surface, creating new crust. Divergent zones in oceanic plates form a geological feature called a ridge, forced upward by the pressure of the rising magma.renches are geological features formed by convergent boundaries. When two tectonic plates converge, the heavier plate is forced downward, creating a subduction zone. This process results in the formation of a trench. The Marianas Trench is an example of a trench formed by the convergence of two oceanic plates.