Deep ocean currents are driven by density and temperature gradients. Thermohaline circulation is also known as the ocean's conveyor belt (which refers to deep ocean density driven ocean basin currents). These currents, called submarine rivers, flow under the surface of the ocean and are hidden from immediate detection.
The light-colored material is in areas of the Moon called the highlands, which represent the earliest crust on the Moon. Impact cratering shattered this crust and often deformed it, pushing some of it into mountain-high impact crater rims or ejecting it across the surface of the Moon.
And hereâs the amazing surpriseâ¦. You would think that the far side of the Moon would look like the near side, but check out the two hemispheresâ¦Theyâre totally different. The near side of the has huge regions of ancient lava flows, called maria.