Now a thick layer of warm water (oil) covers the surface in the East, this cuts off the nutrient-rich cold water from upwelling to the surface.
(this; cuts off; the nutrient-rich cold water; from upwelling to the surface) Context(this cuts off,List([70, 83))):(a thick layer of warm water; covers; the surface in the East; T:Now)
this cuts off,List([70, 83))
this a thick layer of warm water
cuts off covers
the nutrient-rich cold water from upwelling to the surface
the surface in the East T:Now