"undersea sills"@en . . . "300386919" . "2013-08-02T14:56:44"^^ . "2013-10-12T10:20:23"^^ . "sills, undersea"@en . . "Low parts of an underwater gap that are separated by basins; includes similar features at the mouthes of fjords."@en . "undersea sill"@en .