The Diamantina Fracture Zone (DFZ) is an area of the south-eastern

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...

seafloor, consisting of a range of ridges and trenches. It lies to the south of the mideastern Indian Ocean features of the

Wharton Basin Wharton Basin is the marine area of the north east quarter of the Indian Ocean. It is named after William Wharton (1843-1905), Hydrographer of the Navy. Alternative names are Cocos Basin (after the Cocos Islands) and West Australian Basin. It ...

and

Perth Basin The Perth Basin is a thick, elongated sedimentary basin in Western Australia. It lies beneath the Swan Coastal Plain west of the Darling Scarp, representing the western limit of the much older Yilgarn Craton, and extends further west offshore. C ...

, and to the south west of the

Naturaliste Plateau The Naturaliste Plateau is one of several large submarine plateaus extending from Western Australia into the Indian Ocean. It is a rectilinear plateau that covers an area of 90,000 square kilometres. Its width is about east-west and north-so ...

Escarpment

Being parallel to the

Southeast Indian Ridge The Southeast Indian Ridge (SEIR) is a mid-ocean ridge in the southern Indian Ocean. A divergent tectonic plate boundary stretching almost between the Rodrigues Triple Junction () in the Indian Ocean and the Macquarie Triple Junction () in the ...

, the Diamantina Fracture Zone is not a true

fracture zone A fracture zone is a linear feature on the ocean floor—often hundreds, even thousands of kilometers long—resulting from the action of offset mid-ocean ridge axis segments. They are a consequence of plate tectonics. Lithospheric plates on eit ...

in the sense used in

plate tectonics Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large ...

, but rather an

escarpment An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''esca ...

, separating two oceanic plateaus. Its extension to the west is called the Diamantina Escarpment. This is the southern border of the

Broken Ridge Plateau The Broken Ridge or Broken Plateau is an oceanic plateau in the south-eastern Indian Ocean. The Broken Ridge once formed a large igneous province (LIP) together with the Kerguelen Plateau. When Australia and Antarctica started to separate, th ...

. All these features are mirrored by corresponding topography on the other side of the

. The Broken Ridge Plateau was formed at the ridge together with the

Kerguelen Plateau The Kerguelen Plateau (, ), also known as the Kerguelen–Heard Plateau, is an oceanic plateau and a large igneous province (LIP) located on the Antarctic Plate, in the southern Indian Ocean. It is about to the southwest of Australia and is ...

Exploration

The Diamantina Fracture Zone was first detected by and RV ''Argo'' in 1960. It is named after , which conducted further exploration in 1961. Professor Alan Jamieson from

The University of Western Australia The University of Western Australia (UWA) is a public research university in the Australian state of Western Australia. The university's main campus is in Perth, the state capital, with a secondary campus in Albany and various other facilities ...

led a scientific expedition to the eastern margin of the DFZ, which enters the southwest corner of the Australian exclusive economic zone. Professor Jamieson's team deployed baited landers beyond water depth aiming to document the biodiversity and geology of the region. Two hadal

snailfish The Liparidae, commonly known as snailfish or sea snails, are a family of marine scorpaeniform fishes. Widely distributed from the Arctic to Antarctic Oceans, including the oceans in between, the snailfish family contains more than 30 genera ...

were captured during this voyage at , both of which are believed to be new species.

Bathymetry

The first high-resolution multibeam bathymetry of the central DFZ was collected between June 2014 and June 2016, for the purpose of searching for

Malaysia Airlines Flight 370 Malaysia Airlines Flight 370 (MH370/MAS370) was an international passenger flight operated by Malaysia Airlines that disappeared on 8 March 2014 while flying from Kuala Lumpur International Airport in Malaysia to its planned destination ...

(MH370), which disappeared on 8 March 2014. This revealed that the DFZ has a depth of more than . Later research using multibeam bathymetry data available from Geoscience Australia and the GMRT (Global Multi-Resolution Topography) Synthesis, infilled with data derived from the GEBCO_2014 global bathymetry dataset, suggested that the deepest point in the fracture zone would be at in the

Dordrecht Deep The Dordrecht Deep is located in the Diamantina Trench southwest of Perth, Western Australia. The Diamantina Trench is in the eastern part of the larger Diamantina Fracture Zone, which stretches from the Ninety East Ridge to the Naturaliste Pl ...

, within the axis of the fracture zone, with a maximum water depth of between . Based on this research, it was suggested that the Dordrecht Deep within the DFZ in the southeast Indian Ocean, and the

Sunda Trench The Sunda Trench, earlier known as and sometimes still indicated as the Java Trench, is an oceanic trench located in the Indian Ocean near Sumatra, formed where the Australian- Capricorn plates subduct under a part of the Eurasian Plate. It is ...

in the eastern Indian Ocean (~), are the two candidates for the deepest points in the Indian Ocean. Lander mudsrc

To resolve this debate, the Diamantina Fracture Zone was surveyed by the

Five Deeps Expedition Victor Lance Vescovo (born 1966) is an American private equity investor, retired naval officer, space tourist and undersea explorer. He is a co-founder and managing partner of private equity company Insight Equity Holdings. Vescovo achieved the ...

in March 2019 by the Deep Submersible Support Vessel DSSV ''Pressure Drop'', equipped with a full-ocean depth Kongsberg SIMRAD EM124 multibeam echosounder system. Using this echosounder and direct measurement by a

Benthic lander Benthic landers are observational platforms that sit on the seabed or benthic zone to record physical, chemical or biological activity. The landers are autonomous and have deployment durations from a few days (for biological studies) to several ...

, a maximum water depth of m ± was measured for the Dordrecht Deep, at , deeper than and ~ southwest of the Stewart and Jamieson (2019) GEBCO_14-derived location. This confirmed that the Diamantina Fracture Zone does not contain the deepest point in the Indian Ocean, but may be the second deepest point after the Sunda Trench. The shallowest point in the area is the point in the Broken Ridge, close to

Ninety East Ridge The Ninety East Ridge (also rendered as Ninetyeast Ridge, 90E Ridge or 90°E Ridge) is a mid-ocean ridge on the Indian Ocean floor named for its near-parallel strike along the 90th meridian at the center of the Eastern Hemisphere. It is approxima ...

.Stow, D. A. V. (2006) ''Oceans : an illustrated reference'' Chicago : University of Chicago Press, - page 127 for map of Indian Ocean and ridges

References

{{reflist

External links

Location on Google map
Fracture zones Oceanic trenches of the Indian Ocean

Escarpment

Exploration

Bathymetry

See also

References

External links