The Australian-Antarctic Rise [1] [2] - the rise of the bottom in the southeastern Indian Ocean between 80 and 160 ° east longitude. It connects the Central Indian Ridge and the South Pacific Rise [3] . Together with the East Indian Ridge, it forms the borders of the eastern part of the Australasian segment of the Indian Ocean bed .
The length of the Australian-Antarctic Rise is 6,000–6,500 km , the average width is 500–550 km [3] , and the maximum width is 800 km [4] . The smallest depth above the ridge is 1145 m [4] . In the eastern part of the uplift are the highest marks of the bottom (1648 and 1689 m) [3] . The elevation is mainly hilly and low mountain [5] . The surface is covered mainly by calcareous aleuritic- clayey silts [3] .
Borders
The western end of the uplift is located in the region of the islands of Amsterdam and Saint-Paul . There, turning to the north, it passes into the Central Indian Range . Amsterdam [5] is separated from it by a fault . In English-speaking and some Russian-language literature, this uplift is considered together and this ridge is grouped together under the name Southeast Indian Ridge [6] [7] . In the east, the Australian-Antarctic Rise ends with the triple point Macquarie ( ) [7] , where it connects with the Macquarie Ridge and the South Pacific Rise [8] .
Morphology
At the western end of the uplift - in the area of the Amsterdam Plateau - it has practically no rift valley. East of the shallow valley appears, but about 82 ° in. it is replaced by a hill (the appearance of which is explained by the influence of the Kerguelen hot spot). Further east, it again gives way to rift valleys of increasing depth. Within the Australian-Antarctic discordance, this valley is rather deep, but at its eastern edge it abruptly gives way to an elevation that stretches to the eastern end of the Australia-Antarctic uplift [7] .
Spreading
Spreading on the Australian-Antarctic Uplift occurs at an average speed for the mid-ocean ridges . At the western end of the uplift, it is minimal: 6.8 cm / year. To the east, the speed grows, reaching a maximum (7.56 cm / year) of about 114 ° East, and then slowly decreases. In this regard, on the uplift, there are also landforms characteristic of rapidly moving ridges, and inherent in slowly moving ridges, and areas of intermediate morphology [7] . In particular, in some places there are rift valleys (objects characteristic of zones of slow spreading) [7] , but for the most part of the length of the uplift there are none [5] .
Notes
- ↑ Indian Ocean // Peace Atlas / comp. and prepare. to ed. PKO "Cartography" in 2009; Ch. ed. G. V. Pozdnyak . - M .: PKO "Cartography": Onyx, 2010. - p. 198—199. - ISBN 978-5-85120-295-7 (Cartography). - ISBN 978-5-488-02609-4 (Onyx).
- ↑ Australian-Antarctic uplifting // Dictionary of geographical names of foreign countries / resp. ed. A.M. Komkov . - 3rd ed., Pererab. and add. - M .: Nedra , 1986. - p. 8.
- ↑ 1 2 3 4 Australian-Antarctic Uplift // Great Soviet Encyclopedia : [in 30 vol.] / Ch. ed. A. M. Prokhorov . - 3rd ed. - M .: Soviet Encyclopedia, 1969-1978.
- ↑ 1 2 Australian-Antarctic uplift - article from the Great Encyclopedic Dictionary
- ↑ 1 2 3 Pirozhnik II., Rylyuk G.Ya., Elovicheva Ya.K. 8.3. Indian Ocean // Geography of the World Ocean. - 2006. - S. 158–159.
- 14. Laughton AS, Matthews DH, Fisher RL Chapter 14. The structure of the Indian Ocean // New Years Floor: Regional Observations Concepts / Arthur E. Maxwell, Edward Bullard, J. Lamar Worzel. - Harvard University Press, 1971. - P. 547. - 680 p. - ISBN 0-674-01732-3 .
- ↑ 1 2 3 4 5 Rozova A.V., Dubinin E.P. Peculiarities of the bottom topography and morphostructural segmentation of the rift zone of the Southeast Indian Ridge // Vestnik KRAUNC. Earth sciences. - 2006. - Vol. 8 - No. 2 . - S. 30–42 .
- ↑ Selkirk PM, Seppelt RD, Selkirk DR // Subantarctic Macquarie Island: Environment and Biology. - Cambridge University Press, 1990. p. 45–46. - 285 p. - ISBN 0-521-26633-5 .