Regarding eastern orthodox churches, how many separate churches are there, and which has the largest membership?

There are 14 self-governing churches, and Romanian church has 20% of Eastern Orthodox Christians.

Explanation:

a mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. this uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.a geomagnetic reversal is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged.