It would be an estuary. I attached a picture of one if you'd like to see what it looks like :)
Geothermal heat, is heat being pulled from the earth loop, creating warm air for us. Iceland uses geothermal heating for heat and electricity.
The water cycle consists of three major processes: evaporation, condensation, and precipitation. Evaporation is the process of a liquid's surface changing to a gas. In the water cycle, liquid water (in the ocean, lakes, or rivers) evaporates and becomes water vapor.
The atmosphere and Earth's interior are layered by density. Gravity pulls more strongly on denser materials so denser materials are at the center of things. Earth's core, at its center, is denser than its crust.