text: does the magma flow/movement is affected by the ocean current or visa versa? i was thinking of combining the idea of natural disaster from the movie, "the day after tomorrow" and "the core". magma flow occurs due to internal pressue in the mantle below the core. if a large amound of magma surfaces underwater, becoming lava, it would cause a change in local flows as convection currents result from uneven heating of the water, but there wouldn't be a significant overall effect due to the large heat capacity of the huge oceans.