mid-ocean ridge

American  

[mid-oh-shuhn rij] / ˈmɪdˌoʊ ʃən ˈrɪdʒ /

noun

Geology, Oceanography.

1. any of several seismically active submarine mountain ranges that extend through the Atlantic, Indian, and Pacific Oceans: each is hypothesized to be the locus of seafloor spreading.

---

mid-ocean ridge Scientific  

/ mĭd′ō′shən /

1. A long mountain range on the ocean floor, extending almost continuously through the North and South Atlantic Oceans, the Indian Ocean, and the South Pacific Ocean. A deep rift valley is located at its center, from which magma flows and forms new oceanic crust. As the magma cools and hardens it becomes part of the mountain range. The mid-ocean ridge is approximately 1,500 km (930 mi) wide, 1 to 3 km (0.62 to 1.86 mi) high, and over 84,000 km (52, 080 mi) long.

2. See more at sea-floor spreading

---

Etymology

Origin of mid-ocean ridge

First recorded in 1960–65

Example Sentences

As the continents spread apart, they studied the changing length of the mid-ocean ridge — a chain of underwater volcanoes — predicted by the model.

From New York Times • Feb. 7, 2024

The North American and Eurasian plates are pulling away from each other at a rate of one to two inches per year, gradually unzipping the floor of the Atlantic Ocean to form a mid-ocean ridge.

From Scientific American • Aug. 24, 2022

Jackson, M. G. & Carlson, R. W. Homogenous superchondritic 142Nd/144Nd in the mid-ocean ridge basalt and ocean island basalt mantle.

From Nature • Feb. 27, 2018

As the mid-ocean ridge itself started to subduct, the relative motion had changed.

From Textbooks • Jan. 1, 2017

All 135 cores of sediment it has collected from the ocean floor fit into a neat pattern: the farther from the mid-ocean ridge they were drilled, the older they proved to be.

From Time Magazine Archive