Researcher Ridge
Researcher Ridge is an underwater ridge in the Northern Atlantic Ocean. It appears to be a chain of seamounts named Gollum Seamount, Vayda Seamount, Bilbo Seamount, Gandalf Seamount, The Shire Seamount, Pippin Seamount, Merry Seamount, Molodezhnaya Seamount, Frodo Seamount, Sam Seamount and Mount Doom Seamount that were likely formed by a hotspot.
Names
In 1974, the United States Board on Geographic Names formally approved the name Researcher Ridge in honor of, a National Oceanic and Atmospheric Administration oceanographic research ship which discovered the ridge in 1971. Vayda Seamount is named after a Russian research vessel, Vayda, and the name of Molodezhnaya Seamount refers to young scientists aboard Vayda. The ridge's other seamounts are named after characters and locations in the fantasy novel The Lord of the Rings.Geography and geomorphology
Researcher Ridge lies in the Atlantic Ocean on the western side of the Mid-Atlantic Ridge, just south of the Fifteen-Twenty fracture zone. The Mid-Atlantic Ridge lies about east of Researcher Ridge.The ridge is a chain of individual seamounts. It is about long with an east-southeast-to-west-northwest strike and its minimum depth decreases eastward to, concordant with mean water depth. The individual seamounts that make up the ridge are, from east to west, Gollum Seamount, Vayda Seamount, Bilbo Seamount, Gandalf Seamount, The Shire Seamount, Pippin Seamount, Merry Seamount, Molodezhnaya Seamount, Frodo Seamount, Sam Seamount, and Mount Doom Seamount. Small cones occur on the surface of Vayda Seamount, which rises to a depth of about below sea level; many of these seamounts appear to be guyots. Only Bilbo Seamount and Vayda Seamount show clear evidence of once having been emerged islands.
Geology
A number of explanations have been forwarded to explain the existence of this ridge, from hotspots fed by a mantle plume over the presence of enriched mantle to the activity of the triple junction between Africa, North America, and South America. A hotspot origin is considered to be the most likely explanation; according to this theory a mantle plume built Researcher Ridge until the hotspot was "captured" by the Mid-Atlantic Ridge. A well-known section of the Mid-Atlantic Ridge that has erupted enriched rocks lies between 14 and 15 degrees North and also features the Logatchev hydrothermal field.The oceanic crust underlying Researcher Ridge has an age ranging between 20 million and 40 million years, increasing westwards. An en echelon graben named Researcher Trough lies north of Researcher Ridge.