Answer: Ice in the North and South Pole triggers the movement of ocean currents by starting a motion called the global conveyor belt. When water freezes in these areas, the water surrounding the newly formed ice decreases in temperature and becomes saltier. This results in an increase in density, so the water sinks to the bottom of the ocean floor where it becomes a cold current. Afterall, the water has to move somewhere so it travels horizontally to spread out over the surface of the earth. Warm water then takes its place and moves to the North. One event such as water freezing in the North and South Pole has resulted in something called the global conveyor belt.
Explanation:
