中脊

zhōngjǐ
mid-ocean ridge (geology)

CEDICT

geology

Entry Composition

1 中 zhōng
  1. within; among; in
  2. middle; center
  3. while (doing sth); during
  4. (dialect) OK; all right
2 脊 jǐ
  1. (bound form) spine; backbone
  2. (bound form) ridge