Detrital and authigenic minerals in sediments from the western part of the Indian Ocean

1986 ◽  
Vol 50 (355) ◽  
pp. 69-74 ◽  
Author(s):  
A. E. Tsirambides
Keyword(s):  
Indian Ocean ◽  
Oxygen Isotope ◽  
Western Indian Ocean ◽  
The Other ◽  
Authigenic Minerals ◽  
Volcanic Material ◽  
Two Samples ◽  
The Indian Ocean ◽  
Isotope Analyses ◽  
Mn Oxides

AbstractMineralogical and oxygen isotope analyses have been performed on nine western Indian Ocean core samples in order to distinguish the detrital from authigenic minerals in the sediments. Following the removal of carbonates, organic constituents and Fe and Mn oxides, the residue was separated into five size fractions, the principal minerals present being feldspar, quartz, clinoptilolite, and clay minerals.Oxygen isotope compositions for two samples reflect an authigenic origin for clinoptilolite by the submarine alteration of volcanic material. Oxygen isotope compositions of two separates (free from feldspar and clays) suggest a detrital origin for the quartz in this area. The same mode of origin is apparent for the other components too, except possibly for some smectite which may have formed authigenically.

Shallow overturning circulation of the Western Indian Ocean

2005 ◽  
Vol 363 (1826) ◽  
pp. 143-149 ◽  
Author(s):  
Friedrich A. Schott
Keyword(s):  
Indian Ocean ◽  
Southern Hemisphere ◽  
Indian Subcontinent ◽  
Western Indian Ocean ◽  
Southwest Monsoon ◽  
The Other ◽  
Return Flow ◽  
Northeast Monsoon ◽  
Equatorial Upwelling ◽  
The Indian Ocean

The Indian Ocean differs from the other two oceans in not possessing an eastern equatorial upwelling regime. Instead, the upwelling occurs dominantly in the northwestern Arabian Sea and, to a lesser degree, around the Indian subcontinent. Subduction, on the other hand, occurs dominantly in the Southern Hemisphere. The result is a shallow Cross–Equatorial Cell connecting both regimes. The northward flow at thermocline levels occurs as part of the Somali Current and the southward upper–layer return flow is carried by the Ekman transports that are directed southward in both hemispheres. The main forcing is by the Southwest Monsoon that overwhelms the effects of the Northeast Monsoon and is the cause for the annual mean Northern Hemisphere upwelling and southward Ekman transports. In the Southern Hemisphere, the annual mean upwelling at the northern rim of the Southeast Trades causes a zonally extended open–ocean upwelling regime that is apparent in isopycnal doming in the 3–12○ S band; it drives a shallow Subtropical Cell.

Editorial Introduction

2020 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Editors of the JIOWS
Keyword(s):  
Nineteenth Century ◽  
Indian Ocean ◽  
Western Indian Ocean ◽  
Late Nineteenth Century ◽  
Fourth Volume ◽  
History Of ◽  
The Indian Ocean ◽  
Complex Relationships ◽  
Indian Ocean World ◽  
Shed Light

The editors are proud to present the first issue of the fourth volume of the Journal of Indian Ocean World Studies. This issue contains three articles, by James Francis Warren (Murdoch University), Kelsey McFaul (University of California, Santa Cruz), and Marek Pawelczak (University of Warsaw), respectively. Warren’s and McFaul’s articles take different approaches to the growing body of work that discusses pirates in the Indian Ocean World, past and present. Warren’s article is historical, exploring the life and times of Julano Taupan in the nineteenth-century Philippines. He invites us to question the meaning of the word ‘pirate’ and the several ways in which Taupan’s life has been interpreted by different European colonists and by anti-colonial movements from the mid-nineteenth century to the present day. McFaul’s article, meanwhile, takes a literary approach to discuss the much more recent phenomenon of Somali Piracy, which reached its apex in the last decade. Its contribution is to analyse the works of authors based in the region, challenging paradigms that have mostly been developed from analysis of works written in the West. Finally, Pawelczak’s article is a legal history of British jurisdiction in mid-late nineteenth-century Zanzibar. It examines one of the facets that underpinned European influence in the western Indian Ocean World before the establishment of colonial rule. In sum, this issue uses two key threads to shed light on the complex relationships between European and other Western powers and the Indian Ocean World.

scholarly journals A Central Indian Ocean Mode and Heavy Precipitation during the Indian Summer Monsoon

2017 ◽  
Vol 30 (6) ◽  
pp. 2055-2067 ◽  
Author(s):  
Lei Zhou ◽  
Raghu Murtugudde ◽  
Dake Chen ◽  
Youmin Tang
Keyword(s):  
Indian Ocean ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Critical Role ◽  
Western Indian Ocean ◽  
Heavy Precipitation ◽  
Central Indian Ocean ◽  
Monsoonal Precipitation ◽  
Monsoon System ◽  
The Indian Ocean

A central Indian Ocean (CIO) mode is found to play a critical role in driving the heavy precipitation during the Indian summer monsoon (ISM). It is typically denoted with a combination of intraseasonal sea surface temperature (SST) anomalies and intraseasonal wind anomalies over the central Indian Ocean, and it preserves the mechanistic links among various dynamic and thermodynamic fields. Like a T junction, it controls the propagation direction of the intraseasonal variabilities (ISVs) originating in the western Indian Ocean. During the ISM, the CIO mode creates an environment favorable for the northward-propagating mesoscale variabilities. These results unveil the relation between the subseasonal monsoonal precipitation and the CIO mode in the ocean–atmosphere system in the Indian Ocean. The identification of the CIO mode deepens our understanding of the coupled monsoon system and brightens the prospects for better simulation and prediction of monsoonal precipitation in the affected countries.

Gujarat in the History of the Indian Ocean

2019 ◽  
pp. 52-67
Author(s):  
Lakshmi Subramanian
Keyword(s):  
Indian Ocean ◽  
Western Indian Ocean ◽  
Maritime History ◽  
Historical Knowledge ◽  
History Writing ◽  
New Methods ◽  
History Of ◽  
The Indian Ocean

This chapter takes a stock taking exercise of the history writing on Gujarat and Indian maritime history over the last five decades. It identifies the major shifts and emphases that mark the nature of historical knowledge. What these hold for the discipline of history in general and how these inflect the case study of Gujarat in particular are examined. The intention of such a stock taking exercise is also to consider the importance of recovering and reading new and local archives and of incorporating new methods into standard historical work. The author also explores the most significant shifts that have emerged in the recent historiography of the Indian Ocean and of maritime Gujarat: study of law and piracy and Muslim seafaring and sailing practices in the western Indian Ocean.

Genetic variation and relationships among Afrotropical species of Myotis (Chiroptera: Vespertilionidae)

2019 ◽  
Vol 100 (4) ◽  
pp. 1130-1143 ◽  
Author(s):  
Bruce D Patterson ◽  
Paul W Webala ◽  
Julian C Kerbis Peterhans ◽  
Steven M Goodman ◽  
Michael Bartonjo ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Maximum Likelihood ◽  
Indian Ocean ◽  
Nuclear Data ◽  
The Other ◽  
Data Sets ◽  
Species Trees ◽  
Nuclear Introns ◽  
Geographic Structure ◽  
The Indian Ocean

Abstract The genus Myotis is nearly cosmopolitan and the second-most speciose genus of mammals, but its Afrotropical members are few and poorly known. We analyzed phylogenetic and phylogeographic relationships of six of the eight known Afrotropical species using Cytb and sequences from four nuclear introns. Using Bayesian and maximum-likelihood approaches to generate single-locus, concatenated, and species trees, we confirmed prior evidence that the clade containing Afrotropical Myotis also contains both Palearctic and Indomalayan members. Additionally, we demonstrate that M. bocagii is sister to the Indian Ocean species M. anjouanensis, that this group is sister to M. tricolor and the Palearctic M. emarginatus, and find evidence suggesting that M. welwitschii is the earliest-diverging Afrotropical species and sister to the remainder. Although M. tricolor and M. welwitschii are both currently regarded as monotypic, both mitochondrial and nuclear data sets document significant, largely concordant geographic structure in each. Evidence for the distinction of two lineages within M. tricolor is particularly strong. On the other hand, geographic structure is lacking in M. bocagii, despite the current recognition of two subspecies in that species. Additional geographic sampling (especially at or near type localities), finer-scale sampling (especially in zones of sympatry), and integrative taxonomic assessments will be needed to better document this radiation and refine its nomenclature.

New genera, species and occurrence records of Goniasteridae (Asteroidea; Echinodermata) from the Indian Ocean

Zootaxa ◽  
2018 ◽  
Vol 4539 (1) ◽  
pp. 1 ◽  
Author(s):  
CHRISTOPHER L. MAH
Keyword(s):  
Indian Ocean ◽  
Deep Sea ◽  
Western Indian Ocean ◽  
Gut Contents ◽  
New Genera ◽  
Late 20Th Century ◽  
The North ◽  
Marine Habitats ◽  
The Indian Ocean ◽  
Occurrence Records

Modern goniasterids are the most numerous of living asteroids in terms of described genera and species and they have important ecological roles from shallow to deep-water marine habitats. Recent MNHN expeditions and historical collections in the USNM have resulted in the discovery of 18 new species, three new genera and multiple new occurrence records from the western Indian Ocean region including Madagascar, Glorioso and Mayotte islands, Walters Shoal, South Africa, and Somalia. This report provides the first significant contribution to knowledge of deep-sea Asteroidea from the Indian Ocean since the late 20th Century. Several deep-sea species, previously known from the North Pacific are now reported from the western Indian Ocean. Gut contents from Stellaster and Ogmaster indicate deposit feeding. Feeding modes of this and other deep-sea species are discussed. Comments are made on fossil members of included taxa. A checklist of Indian Ocean Goniasteridae is also included.

Two new species of Trevathana (Crustacea, Cirripedia, Balanomorpha, Pyrgomatidae) from the Western Indian Ocean and French Polynesia

Zootaxa ◽  
2009 ◽  
Vol 2116 (1) ◽  
pp. 46-52 ◽  
Author(s):  
YAIR ACHITUV ◽  
YAAKOV LANGZAM
Keyword(s):  
New Species ◽  
Indian Ocean ◽  
Western Indian Ocean ◽  
French Polynesia ◽  
Terra Incognita ◽  
Two New Species ◽  
The Indian Ocean ◽  
Basal Margin ◽  
Ocean Islands

Two new species of the Pyrgomatid barnacle Trevathana are described: Trevathana synthesysae nov. sp., extracted from Plesiastrea versipora from the Indian Ocean Islands Réunion and Mauritius, and Trevathana isfae nov. sp. from a colony of Favia stelligera from French Polynesia, which, until recently, was terra incognita with regard to coral-inhabiting barnacles. The two new species are distinctive by their relatively broad scutum as compared to Trevathana dentatum, their prominent adductor ridge extending beyond the basal margin of the scutum, and their quadrangular tergum.

Belts and roads every- and nowhere: Conceptualizing infrastructural corridorization in the Indian Ocean

2020 ◽  
Vol 38 (5) ◽  
pp. 815-819
Author(s):  
Henryk Alff
Keyword(s):  
Indian Ocean ◽  
Silk Road ◽  
The Other ◽  
Assemblage Theory ◽  
Static State ◽  
Maritime Silk Road ◽  
The Indian Ocean ◽  
The One ◽  
Human Actors

This article scrutinizes the Maritime Silk Road Initiative by framing it not as a static, state-centric device to channel Chinese developmental ambitions, but by emphasizing the flexible character of its production and the provisional configuration of its materialization. It draws on assemblage theory as a conceptual angle to, on the one hand, focus on the agentive character of human and non-human ‘actors’ such as ‘traveling’ discourses of development or infrastructures to explore Maritime Silk Road Initiative’s materialization ‘on the ground’ in its emergent rather than resultant way, on the other.

scholarly journals Culture and Diplomacy: Maritime Cultural Heritage of the Western Indian Ocean

2020 ◽  
Vol 76 (3) ◽  
pp. 375-391 ◽  
Author(s):  
Himanshu Prabha Ray
Keyword(s):  
Indian Ocean ◽  
Cultural Heritage ◽  
Cultural Practices ◽  
Western Indian Ocean ◽  
World Heritage ◽  
World Heritage Convention ◽  
Academic Networks ◽  
The Indian Ocean ◽  
Global Platform ◽  
Cultural Routes

The article argues that UNESCO’s 1972 World Heritage Convention provides a global platform for projecting not only India’s maritime cultural heritage but also building bridges and collaborative networks with other Indian Ocean littoral countries for the promotion of shared cultural practices and traditional knowledge systems of the Indian Ocean. Unfortunately, this collaborative research aspect of the World Heritage Convention has yet to be tapped for nominating and inscribing transnational heritage or cultural routes across the Ocean. This is despite the fact that India was the founder member of the intergovernmental organisation, Indian Ocean Rim Association, one of whose thrust areas relates to promoting cultural heritage on the UNESCO platform. Given India’s rich maritime past, there is an urgent need to implement measures to establish academic networks with littoral countries for not only creating awareness of the maritime cultural heritage of the Indian Ocean but also harnessing linkages between maritime communities for building a culturally diverse but harmonious future.

India’s Strategic Interests and Partnership with Island States of Africa in the Western Indian Ocean Region

2020 ◽  
Vol 7 (2) ◽  
pp. 227-243
Author(s):  
Raghvendra Kumar
Keyword(s):  
Indian Ocean ◽  
Western Indian Ocean ◽  
Power Dynamics ◽  
Indian Ocean Region ◽  
Island States ◽  
Global Power ◽  
Challenges And Opportunities ◽  
Ocean Region ◽  
Indian Ocean Island ◽  
The Indian Ocean

The Indian Ocean has turned into the new geographical centre of power, where global power dynamics is being revealed. It has been transformed into a geostrategic heartland, forecasting new challenges and opportunities, and at the core of this is an emerging power, India, which, being located at a strategic juncture in the Indian Ocean, shapes much of this geostrategic transformation. Therefore, sustaining and improving security and continuing economic expansion, with an increased strategic presence in the region to safeguard its national, regional and global interests are some of the elements which greatly influence India’s involvement with the strategic island states of Africa in the Western Indian Ocean Region. In this backdrop, this article has tried to contextualise the ‘Western Indian Ocean Region’ and ‘situate the actors’ to explore the various contours of geostrategic engagements the region is witnessing. Further, the article examines India’s strategic interests in the Western Indian Ocean, which are critical for its global power aspirations. It discusses the linkages between India and the Western Indian Ocean island states of Africa, which would become the precursor for newer strategies and help in harnessing the potential of mutually beneficial cooperation. Lastly, the article seeks to re-engage with the island states of Africa to help forge a deeper cultural and strategic bond, which would be crucial in balancing the power equation in the region.

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