List of fracture zones

Fracture zones are common features in the geology of oceanic basins. Globally most fault zones are located on divergent plate boundaries on oceanic crust. This means that they are located around mid-ocean ridges and trend perpendicular to them. The term fracture zone is used almost exclusively for features on oceanic crust, similar structures on continental crust are instead termed transform or strike slip faults, a denomination active fracture zones also can have. Some fracture zones have been created by mid-ocean ridge segments that have been subducted and may not longer exist.

Contents

Pacific Ocean

Most fracture zones in the Pacific Ocean originate from large mid-ocean ridges (also called "rises") such as the East Pacific Rise, Chile Rise and Juan de Fuca Ridge. The plates that hosts the fractures are Nazca, Pacific, Antarctic, Juan de Fuca and Cocos among others. Fracture zones being subducted under Southern and Central America are generally southwest-northeast oriented reflecting the relative motion of Cocos, Nazca and the Antarctic Plates.

Chile Rise

The fracture zones of the Chile Rise trends in a west to east fashion with the most southern ones taking a slightly more southwest to northeast orientation. This non perpendicular relation to Chiles coast reflects the oblique subduction of Nazca Plate under southern Chile. West of Chile rise the fracture zones are hosted in the Antarctic Plate. Some fracture zones such as Chile and Valdivia makes up large sections of the Nazca-Antarctic Plate boundary.

Name Minimum length
in km		 Length as plate
boundary in km		 Coordinates
Chile 2250 1100
Chiloé 1750 50
Darwin 50
Desolación 0
Esmeralda 0
Guafo 1550 280
Guamblin 1300 70
Madre de Dios 0
Mocha 450 0
Taitao 0
Tres Montes 0
Valdivia 2100 650

East Pacific Rise

Name Minimum length
in km		 Length as plate
boundary in km		 Coordinates
Easter
Mendaña 0
Nazca 0
Quiros 0

Galapagos Rise

Juan de Fuca and Gorda Ridges

Molokai and Murray fracture zones shown in the list were created by ridge segments that no longer exist.

Atlantic Ocean

In the Atlantic Ocean most fracture zones originate from the Mid-Atlantic Ridge, which runs from north to south, and are therefore west to east oriented in general. There are about 300 fracture zones, with an average north-south separation of 55 kilometers[1]: two for each degree of latitude. Physically it makes sense to group Atlantic fracture zones into three categories[2]:

  1. Small offset: length of transform fault less than 30 kilometers
  2. Medium offset: offset over 30 kilometers
  3. Large offset: offset several hundreds of kilometers

Mid-Atlantic Ridge (Northern Hemisphere)

Name Minimum length
in km		 Length of
transform fault in km		 Position at Ridge
Saint Paul[3] 1451 454
Saint Peter[3] 333 40
Strakhov[3] (formerly:Four North[4]) 1814 100
Sierra Leone[3] 1111 52
Bogdanov[3] 173 84
Vernadsky[3] 194 107
Doldrums[3] 381 144
Arkhangelskiy[3] 691 99
Vema[3] 822 300
Mercurius[5] 39
Marathon[5] 78
Fifteen Twenty, also known as Barracuda or Cabo Verde[3] 1195 195[5]
Vidal[2] 50
Luymes South[2] 30
Luymes North[2] 24
Snellius[2] 41
Kane[3] 1040 150[6]
Northern[2] 1040 9
Tyro[2] 15
Atlantis[3] 843 66
Cruiser[2] 9
Charis[2] 13
Hayes[3] 624 151
Oceanographer[3] 751 148
Tydeman 21
Pico (to the west)[3][2] 719 67
East Azores (to the east)[3][2] 758 67
Kurchatov[3] 174 20
Petrov[3] 74 9
Maxwell[3] 21
Faraday[3] 506 23
Charlie-Gibbs[3] 1020 350[2]
Bight[3] 336 23
Jan Mayen[3] 374 211
Greenland (to the west)[7] 0 365
Senja (to the east)[7] 0 398

Fracture zones involved in the early opening of the North Atlantic[8]

American side African side
Newfoundland Fracture Zone[9]
Kelvin Fracture Zone Canary Fracture Zone
Cape Fear Fracture Zone Cape Verde Fracture Zone
Bahama Fracture Zone Guinea Fracture Zone

Mid-Atlantic Ridge (Southern Hemisphere)

Name Minimum length
in km		 Length of
transform fault in km		 Position at Ridge
Romanche[3] 2445 950
Chain[3] 1315 269
Ascension[3] 1149 264
Bode Verde[3] 3018 232
Cardno[3] 1649 87
Tetyaev[3] 810 122
Saint Helena[3] 1184 19
Hotspur[3] 1446 113
Martin Vaz[3] 1324 26
Rio Grande[3] 1774 156
Tristan Da Cunha[3] 1014 26
Gough[3] 1057 42
Conrad (to the west)[3] 316 0
Bouvet (to the east)[3] 198 0

Indian Ocean

Carlsberg Ridge

Central Indian Ridge

Lakshadweeo-Chagos Ridge

Southern Ocean

References

The Global Seafloor Fabric and Magnetic Lineation Data Base Project

  1. ^ Gilman, Larry; Lerner, K. Lee "Mid-Ocean-Ridges" Water Encyclopedia http://www.waterencyclopedia.com/Mi-Oc/Mid-Ocean-Ridges.html. Retrieved 2011-11-29 
  2. ^ a b c d e f g h i j k l Müller, R. Dietmar; Roest, Walter R. (1992). "Fracture Zones in the North Atlantic from Combined Geosat and Seasat Data". Journal of Geophysical Research 97 (B3): 3337-3350. http://www.earthbyte.org/people/dietmar/Pdf/Muller_Roest_natl_fz_jgr92.pdf. Retrieved 2011-11-30. 
  3. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak Name from GEBCO gazetteer, position refined by means of etopo2 and sample data of GPlates
  4. ^ Udintsev, G.B. (1996) "Equatorial Segment of the Mid-Atlantic Ridge" Unesco http://www.pdfio.com/k-335380.html. Retrieved 2011-12-05 
  5. ^ a b c Roest, W. R.; Collette, B. J. (1986) "The Fifteen Twenty Fracture Zone and the North American - South American plate boundary" Journal of the Geological Society 143: 833 - 843 doi:10.1144/gsjgs.143.5.0833 
  6. ^ Tucholke, Brian E.; Schouten, Hans (1988-03-01) "Kane Fracture Zone" Marine Geophysical Research 10: 1-39 doi:10.1007/BF02424659 
  7. ^ a b "Map with Jan Mayen, Greenland and Senja Fracture Zones" Ocean Drilling Project http://www-odp.tamu.edu/publications/163X_IR/101/images/01_f01.gif. Retrieved 2011-12-16 
  8. ^ Le Pichon, Xavier; Fox, Paul J. (1971-09-10) "Marginal Offsets, Fracture Zones, and the Early Opening of the North Atlantic" Journal of Geophysical Research 76 (26): 6294-6308 
  9. ^ Auzende, J.M.; Olivet, J.L.; Bonnin, J. (1970) "Marge du Grand Bank et la fracture de Terre-Neuve" (in fr) Compt. Rend. 271: 1063-1066