Mid Ocean Ridge - John Seach

The mid ocean ridge is a constructive plate margin under the sea. It accounts for 80% of global volcanism.
The ridge is 1000 to 4000 km wide and rises 2 to 3 km above the ocean floor.
The whole mass of the earth's oceans is cycled through the volcanic crust every 5 million years.
The mid ocean ridges produce effucive basaltic lavas.
 

Mid ocean ridge
www.volcanolive.com
Copyright John Seach