They can occur anywhere between the Earth's surface; about 700 kilometers<span> below the surface.</span>
They are believed to cause divergence of lithospheric plates at the <span>mid atlantic ridge
</span><span> The currents reallocate heat from a certain place to another through mass motion of fluid (such as molten rock or water), The difference in temperature between core and lithosphere material generate enough force for the divergence to happen.</span>
