, ▁are ▁tradition ally ▁called ▁mid - o cean ▁rid ges . ▁Mid - o cean ▁rid ges ▁around ▁the ▁glo be ▁are ▁linked ▁by ▁plate ▁t ect onic ▁boundaries ▁and ▁the ▁trace ▁of ▁the ▁rid ges ▁across ▁the ▁ocean ▁floor ▁appears ▁similar ▁to ▁the ▁se am ▁of ▁a ▁baseball . ▁The ▁mid - o cean ▁r idge ▁system ▁thus ▁is ▁the ▁longest ▁mountain ▁range ▁on ▁Earth , ▁reaching ▁about ▁. ▁ ▁Global ▁system ▁▁ ▁The ▁mid - o cean ▁rid ges ▁of ▁the ▁world ▁are ▁connected ▁and ▁form ▁the ▁Ocean ▁R idge , ▁a ▁single ▁global ▁mid - o cean ic ▁r idge ▁system ▁that ▁is ▁part ▁of ▁every ▁ocean , ▁making ▁it ▁the ▁longest ▁mountain ▁range ▁in ▁the ▁world . ▁The ▁continuous ▁mountain ▁range ▁is ▁ ▁long ▁( se ver al ▁times ▁longer ▁than ▁the ▁And es , ▁the ▁longest ▁contin ental ▁mountain ▁range ), ▁and ▁the ▁total ▁length ▁of ▁the ▁ocean ic ▁r idge ▁system ▁is ▁ ▁long . ▁ ▁Description ▁ ▁Mor ph ology ▁ ▁At ▁the ▁ ▁spread ing ▁center ▁on ▁a ▁mid - o cean ▁r idge ▁the ▁depth ▁of ▁the ▁se af loor ▁is ▁approximately ▁. ▁On ▁the ▁r idge ▁fl anks ▁the ▁depth ▁of ▁the ▁se af loor ▁( or ▁the ▁height ▁of ▁a ▁location ▁on ▁a ▁mid - o cean ▁r idge ▁above ▁a ▁base - level ) ▁is ▁correl ated ▁with ▁its ▁age ▁( age ▁of ▁the ▁l ith os phere ▁where ▁depth ▁is ▁measured ). ▁The ▁depth - age ▁relation ▁can ▁be