The first thing to keep in mind is that ocean currents are very thin compared to the 12,742-kilometer (7,917-mile) diameter of Earth. They’re only about four kilometers (13,000 feet) deep at most, and ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: Kinga Krzeminska/Getty Images The equator is the imaginary line that horizontally ...

The Equator is a line of latitude that bisects the globe at its widest point, and where the hours of light and darkness are equal throughout the year. The Equator passes through 13 countries: Ecuador, ...