Hydrology of the Indian Ocean. I. The Water Masses in Intermediate Depths of the South-East Indian Ocean

1961 ◽  
Vol 12 (2) ◽  
pp. 129 ◽  
Author(s):  
DJ Rochford
Keyword(s):  
Indian Ocean ◽  
West Indian ◽  
Water Masses ◽  
The South ◽  
North West ◽  
East Indian ◽  
The North ◽  
The Indian Ocean ◽  
The Antarctic ◽  
East Indian Ocean

Three water masses have been identified from maxima and minima in temperature-salinity diagrams for intermediate depths of the south-east Indian Ocean. (1) The Antarctic Intermediate occurred as a salinity minimum within the density range of 7.00-27.28 σt. (2) The North-West Indian Intermediate was found as a salinity maximum within the σt range 27.20-27.50. (3) The Banda Intermediate, lying below the North-West Indian Intermediate, had the characteristic of a salinity minimum within the σt range of 27.28-27.59. Preformed phosphate has been found useful as a third conservative property for the identification of major paths of spreading. The distribution and paths of spreading of the three water masses are shown in charts of the Indian Ocean east of 90�E.

Seasonal variations in the Indian Ocean along 110°E. I. Hydrological structure of the upper 500 m

1969 ◽  
Vol 20 (1) ◽  
pp. 1 ◽  
Author(s):  
DJ Rochford
Keyword(s):  
Indian Ocean ◽  
Surface Waters ◽  
Water Masses ◽  
Surface Currents ◽  
Temperature Changes ◽  
East Indian ◽  
Hydrological Structure ◽  
The Indian Ocean ◽  
The Tropics ◽  
East Indian Ocean

Tropical and subtropical water masses at surface and subsurface depths were separated by their salinity, temperature, oxygen, and nutrient characteristics. The annual mean depths and latitudinal extent of these water masses were determined. Annual changes in the upper 50 m were generally so small relative to those found in other oceans that advection and mixing must have been less important in their genesis than local climatic changes. There was a barely significant seasonal rhythm in surface phosphate and nitrate, with peak occurrences of each some 6 months apart. At each latitude the permanent thermal discontinuity centred around a particular isotherm varied little in intensity during the year, but rose and fell in accordance with surface currents. The thermocline south of c. 18�S. varied little in depth but greatly in intensity during the summer. The depth of the mixed layer was much less in summer and at all times shallower in the tropics. The depth of this layer was governed more by the accumulation of surface waters by zonal currents and eddies, than by wind stress or convective overturn. Therefore there was little difference from south to north, or month to month, in average nutrient values of this mixed column. The movement of the various surface waters, deduced from salinity and temperature changes during the year, usually agrees with geostrophic currents across 110�E, and ships' observations of surface currents in the south-east Indian Ocean.

Mixing Trajectories of Intermediate Depth Waters of the South-East Indian Ocean as Determined by a Salinity Frequency Method

1963 ◽  
Vol 14 (1) ◽  
pp. 1 ◽  
Author(s):  
DJ Rochford
Keyword(s):  
Indian Ocean ◽  
Water Masses ◽  
Intermediate Water ◽  
The South ◽  
Intermediate Depth ◽  
East Indian ◽  
The Core ◽  
Deep Mixing ◽  
Core Method ◽  
East Indian Ocean

A new method for the detection of water masses and for the tracing of their mixing paths is described. Histograms of the salinity frequency distribution on 0.10 σt intervals from σt 26.90 to 27.70 contain modes which indicate the salinity characteristics of the intermediate water masses of the south-east Indian Ocean. These salinity characteristics are used to trace the extent of spreading of the water masses on these σt intervals and to determine trajectories of shallow and deep mixing. Comparison is made of the results obtained by the new method with those by the core method for the water masses and circulation in intermediate depth of the south-east Indian Ocean. The core method in this region has not been able to show the large extent of deep mixing associated with the spreading of the Banda and Antarctic Intermediate water masses. The core method has also failed to show the widespread distribution of patches of Banda water at about 400-500 m throughout the whole south-east Indian Ocean.

scholarly journals The Geology of Portuguese Nyasaland

1922 ◽  
Vol 59 (5) ◽  
pp. 200-212
Author(s):  
Robert R. Walls
Keyword(s):  
Indian Ocean ◽  
East Africa ◽  
The South ◽  
The North ◽  
Dark Continent ◽  
The Indian Ocean

Portuguese Nyasaland is the name given to the most northern part of Portuguese East Africa, lying between Lake Nyasa and the Indian Ocean. It is separated from the Tanganyika territory in the north by the River Rovuma and from the Portuguese province of Mozambique in the south by the River Lurio. The territory measures about 400 miles from east to west and 200 miles from north to south and has an area of nearly 90,000 square miles. This territory is now perhaps the least known part of the once Dark Continent, but while the writer was actually engaged in the exploration of this country in 1920–1, the Naval Intelligence Division of the British Admiralty published two handbooks, the Manual of Portuguese East Africa and the Handbook of Portuguese Nyasaland, which with their extensive bibliographies contained practically everything that was known of that country up to that date (1920). These handbooks make it unnecessary in this paper to give detailed accounts of the work of previous explorers.

Art. VII.—Notes on Persian Belúchistán. From the Persian of Mirza Mehdy Khán. Published Teheran, July, 1875

1876 ◽  
Vol 9 (1) ◽  
pp. 147-154
Author(s):  
A. H. Schindler
Keyword(s):  
Indian Ocean ◽  
Temperate Climate ◽  
The South ◽  
The West ◽  
The North ◽  
The People ◽  
The Indian Ocean ◽  
The Hill ◽  
Cool Climate

The part of Belúchistán now under Persian rule is bounded upon the north by Seistán, upon the east by Panjgúr and Kej, upon the south by the Indian Ocean, and upon the west by Núrámshír, Rúdbár, and the Báshákerd mountains.This country enjoys a variety of climates; almost unbearable heat exists on the Mekrán coast, we find a temperate climate on the hill slopes and on the slightly raised plains as at Duzek and Bampúr, and a cool climate in the mountainous districts Serhad and Bazmán. The heat at Jálq is said to be so intense in summer that the gazelles lie down exhausted in the plains, and let themselves be taken by the people without any trouble.

scholarly journals Eocene to recent development of the South-west Indian Ridge, a consequence of the evolution of the Indian Ocean Triple Junction

1981 ◽  
Vol 64 (3) ◽  
pp. 587-604 ◽  
Author(s):  
John G. Sclater ◽  
Robert L. Fisher ◽  
Phillippe Patriat ◽  
Christopher Tapscott ◽  
Barry Parsons
Keyword(s):  
Indian Ocean ◽  
Triple Junction ◽  
West Indian ◽  
The South ◽  
South West ◽  
The Indian Ocean ◽  
Indian Ridge

A fission track thermochronological study of King George and Livingston islands, South Shetland Islands (West Antarctica)

2004 ◽  
Vol 16 (2) ◽  
pp. 191-197 ◽  
Author(s):  
I. SELL ◽  
G. POUPEAU ◽  
J.M. GONZÁLEZ-CASADO ◽  
J. LÓPEZ-MARTÍNEZ
Keyword(s):  
South Shetland Islands ◽  
West Antarctica ◽  
The South ◽  
North West ◽  
The North ◽  
Early Oligocene ◽  
Barton Peninsula ◽  
Bransfield Basin ◽  
Back Arc ◽  
The Antarctic

This paper reports the dating of apatite fission tracks in eleven rock samples from the South Shetland Archipelago, an island arc located to the north-west of the Antarctic Peninsula. Apatites from Livingston Island were dated as belonging to the Oligocene (25.8 Ma: metasediments, Miers Bluff Formation, Hurd Peninsula) through to the Miocene (18.8 Ma: tonalites, Barnard Point). Those from King George Island were slightly older, belonging to the Early Oligocene (32.5 Ma: granodiorites, Barton Peninsula). Towards the back-arc basin (Bransfield Basin), the apatite appears to be younger. This allows an opening rate of approximately 1.1 km Ma−1 (during the Miocene–Oligocene interval) to be calculated for Bransfield Basin. Optimization of the apatite data suggests cooling to 100 ± 10°C was coeval with the end of the main magmatic event in the South Shetland Arc (Oligocene), and indicates slightly different tectonic-exhumation histories for the different tectonic blocks.

Hydrology of the Indian Ocean. III. Water masses of the upper 500 metres of the South-east Indian Ocean

1964 ◽  
Vol 15 (1) ◽  
pp. 25 ◽  
Author(s):  
DJ Rochford
Keyword(s):  
Indian Ocean ◽  
Persian Gulf ◽  
Water Mass ◽  
Sea Water ◽  
Core Layer ◽  
Water Masses ◽  
Intermediate Water ◽  
Surface Currents ◽  
North West ◽  
East Indian

The following seven water masses have been identified, and their distribution traced during several seasons of the year: Red Sea mass, with the same distribution and properties in 1962 as the north-west Indian Intermediate described in 1959-60; Persian Gulf mass, which is confined to the region south of Indonesia and is limited in extent of easterly flow by the opposing flow of Banda Intermediate water; upper salinity minimum mass, entering via Lombok Strait and moving zonally in the direction of the prevailing surface currents, a secondary movement of this water mass towards north-west Australia is limited by the northern boundary of a south-east Indian high salinity water mass. This latter water mass occurs as three separate core layers north of 22-23� S. The deep core layer mixes with waters of the oxygen maximum below it, the mid-depth core layer mixes with Persian Gulf and upper salinity minimum water masses, and the upper core layer mixes with the Arabian Sea water mass. The latter water mass spreads eastwards to about 120� E. and southwards to north-west Australia, in conformity with surface currents. A sixth water mass enters with the counter-current and is found as a salinity maximum within the thermocline to about 20� S. A seventh water mass characterized by a salinity maximum around temperatures of 28-29�C has a limited distribution and an unknown origin. Both of these water masses move in the direction of surface currents.

scholarly journals Atmospheric microplastic over the South China Sea and East Indian Ocean: abundance, distribution and source

2020 ◽  
Vol 389 ◽  
pp. 121846 ◽  
Author(s):  
Xiaohui Wang ◽  
Changjun Li ◽  
Kai Liu ◽  
Lixin Zhu ◽  
Zhangyu Song ◽  
...  
Keyword(s):  
Indian Ocean ◽  
South China Sea ◽  
South China ◽  
The South China Sea ◽  
Abundance Distribution ◽  
The South ◽  
China Sea ◽  
East Indian ◽  
East Indian Ocean
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