Eltanin fault system

{{Short description|Series of faults that offset the Pacific-Antarctic Ridge}}

{{maplink|frame=yes|frame-align=right|frame-width=275|frame-height=240|frame-long=-105|frame-lat=-66|zoom=2|raw={{Wikipedia:Map data/Fracture zone}}|text=Approximate surface projection on Southern Ocean of Eltanin fault system components (violet). Other nearby fracture zones (orange) and associated features such as probable extension of fracture zones are also shown (lighter orange). Click to expand map to obtain interactive fracture zone details.}}

File:Pacific elevation2.jpg

The Eltanin fault system (Eltanin fracture zone) is a series of six or seven dextral transform faults that offset the Pacific-Antarctic Ridge, a spreading zone between the Pacific plate and the Antarctic plate. This is extending by up to {{convert|7.93|cm/year|abbr=on}}.{{sfn|Sykes|Ekstörm|2011|p=430}} It was named after the oceanographic ship USNS Eltanin.{{sfn|Sykes|Ekstörm|2011|p=422}}

Description

The affected zone of the Pacific-Antarctic Ridge is about {{convert|800|km|abbr=on}} long, between 56° S, 145° W and 54.5° S, 118.5° W,{{Cite journal|author=Lonsdale, Peter|date=1994|title=Structural geomorphology of the Eltanin fault system and adjacent transform faults of the Pacific-Antarctic plate boundary|journal=Marine Geophysical Researches|volume=16|number=2|pages=105–143|doi=10.1007/BF01224756|bibcode = 1994MarGR..16..105L }} southwest of Easter Island, and about as far as one can get from land on planet Earth (48°52.6′S 123°23.6′W).Because of the generally remote character of the epicentral area (the Eltanin fracture zone is indeed close to the point at sea farthest away from any land shore) page 10.497, {{Cite journal|author1=Stewart, Lisa M. |author2=Okal, Emile A.|date=1983|title=Seismicity and Aseismic Slip Along the Eltanin Fracture Zone|journal=Journal of Geophysical Research|volume=88|number=B12|pages=10,495–10,507|url=http://www.earth.northwestern.edu/people/emile/PDF/EAO040.pdf|doi=10.1029/jb088ib12p10495|bibcode = 1983JGR....8810495S }} However, the total offset is about 1600 km. The two major faults in the Eltanin fracture zone are the Heezen transform fault and the Tharp transform fault, usually known as fracture zones as they extend inactively from the Pacific-Antarctic Ridge.{{sfn|Sykes|Ekstörm|2011|p=422}} A third named after Hollister, which is the shortest to the south, also exists and its active transform region has been linked to the other transform regions of the Eltanin fault system.{{sfn|Sykes|Ekstörm|2011|p=422}} They are about {{convert|1000|km|abbr=on}} long and have been in the last 50 years the location of many earthquakes of up to {{M|w|6.4|link=y}}.{{sfn|Sykes|Ekstörm|2011|p=421}} One segment of the Heezen transform has ruptured with an average repeat interval of 4 years.{{sfn|Sykes|Ekstörm|2011|p=422}} Others related faults include the Vacquier transform fault, the Menard transform fault, and the Udintsev fault.{{Cite journal|author=Dosso, L.|date=2005|title=The Pacififi c-Antarctic Ridge between 41°15'S and 52°45'S: Survey and sampling during the PACANTARCTIC 2 cruise|journal=InterRidge News|volume=14|pages=1–4|url=http://www.whoi.edu/science/GG/interridge/oldIR/INFORMATION/IR_News/IndivPDFs05/Dosso05.pdf|display-authors=etal}}

To the northwest, in an almost linear fashion as seafloor features, are the Hollister Ridge and the Louisville Seamount Chain.

Notes

Sources

{{Cite journal|last1=Sykes | first1=Lynn R. |last2=Ekstörm | first2 = Göran|date=2011|title=Earthquakes along Eltanin transform system, SE Pacific Ocean: fault segments characterized by strong and poor seismic coupling and implications for long-term earthquake prediction|journal=Geophysical Journal International|volume=188|number=2|pages=421–434|doi=10.1111/j.1365-246X.2011.05284.x|bibcode = 2012GeoJI.188..421S |doi-access=free}}

Eltanin fault system

Description

See also

Notes

Sources

Further reading