Why are density differences in water one of the primary forces that cause ocean currents?

Denser liquids sink, causing dense water to move under water that is less
dense.

Denser liquids are warmer, and warmer water tends to move toward the
equator.

Fast-moving winds move denser water faster than water that is less
dense.

Less dense liquids sink, resulting in upwelling that moves denser water to
the surface.

the titanic would be the correct answer

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this

fumikage isn't really a bird, and tsuyu does have teeth. tsuyu has a transformation quirk which still allows her to be partially human. otherwise we'd have a large frog running around. fumikage has teeth because again, he isn't a bird. his head was a quirk mixture if i'm correct.