From Google:
seafloor spreadĀ·ing
nounGEOLOGY
noun: sea-floor spreading
the formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges and its subsequent outward movement on either side.
How does sea-floor spreading occur?
A. New materials are beaing added to the asthebosphere
B. Earthquakes break apart the ocean floor
C. Sediment accumulates at the area of spreading
D. Molten materials beneath Earth's crust rises to the surface
1 answer