Answer:
1. Each station can detect how far away the epicenter was. So each station basically has a circle made of possible epicenters. When you have three, you narrow it down to one, final point.
2. Below the tectonic plate is a magma chamber that is shooting up mafic magma. As it emerges, it creates an island. The plate that the magma is puncturing is also happening to be moving, so it makes one island, and it floats on. Think of it as a chimney. It blows a puff of smoke, the wind blows it away. Then another puff emerges, and so on. Those other islands no longer sit on the source of the volcano.
3. Metamorphism occurs when there is enough pressure and heat in order to rearrange the structures of each mineral into a new mineral. Contact metamorphism occurs when lava shoots through and touches other rocks, which heats them up and driving metamorphism. In contact, there is no pressure. In regional, there is a large area of both heat and pressure being applied on the rocks.
