Quaternary history of calcium carbonate fluctuations in the western equatorial Indian Ocean (Somali Basin)

1993 ◽  
Vol 103 (1-2) ◽  
pp. 21-30 ◽  
Author(s):  
P. Divakar Naidu ◽  
Björn A. Malmgren ◽  
Lennart Bornmalm
1989 ◽  
Vol 1 (1) ◽  
pp. 23-30 ◽  
Author(s):  
S.L. Chown

Most of the species in the Ectemnorhinin are cryptogam feeders, angiosperm feeders representing a minority. It is hypothesized that this dearth of angiosperm feeders is due to previous climatic conditions, which precluded angiosperm herbivory, but allowed for the exploitation of a diverse cryptogamic flora, and that only with the post-glacial warm-up of the Subantarctic has angiosperm herbivory become possible. When examined in the light of the Quaternary history of the South Indian Ocean Province islands, evidence obtained from a study of the habitat use, diet and morphology of species within the tribe supports this hypothesis.


1978 ◽  
Vol 9 (1) ◽  
pp. 71-86 ◽  
Author(s):  
Douglas F. Williams ◽  
John Keany

A detailed paleoceanographic history of the Subantarctic region for the last million years was determined using paleomagnetic stratigraphy, radiolarian and planktonic foraminiferal biostratigraphy, and the oxygen isotope record from stages 1 to 13 (0.5 MY) in a deep-sea core (E45-74) from the southern Indian Ocean. Changes in the abundances of Antarctissa strelkovi and Neogloboquadrina pachyderma record 12 glacial/interglacial cycles. The paleoceanographic events based on the combined results of these siliceous and calcareous indexes agree with changes in the global ice-volume record. Calcium carbonate dissolution selectively alters the planktonic foraminiferal fauna and causes test fragmentation and increased numbers of benthic foraminifera and radiolarians. Intense periods of calcium carbonate dissolution are associated principally with glacial episodes and are probably related to increased Antarctic bottom-water activity as well as changes in surface-water mass positions.


2020 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Editors of the JIOWS

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.


Author(s):  
Samia Khatun

Australian deserts remain dotted with the ruins of old mosques. Beginning with a Bengali poetry collection discovered in a nineteenth-century mosque in the town of Broken Hill, Samia Khatun weaves together the stories of various peoples colonized by the British Empire to chart a history of South Asian diaspora. Australia has long been an outpost of Anglo empires in the Indian Ocean world, today the site of military infrastructure central to the surveillance of 'Muslim-majority' countries across the region. Imperial knowledges from Australian territories contribute significantly to the Islamic-Western binary of the post- Cold War era. In narrating a history of Indian Ocean connections from the perspectives of those colonized by the British, Khatun highlights alternative contexts against which to consider accounts of non-white people. Australianama challenges a central idea that powerfully shapes history books across the Anglophone world: the colonial myth that European knowledge traditions are superior to the epistemologies of the colonized. Arguing that Aboriginal and South Asian language sources are keys to the vast, complex libraries that belie colonized geographies, Khatun shows that stories in colonized tongues can transform the very ground from which we view past, present and future.


Author(s):  
Roy Livermore

Tuzo Wilson introduces the concept of transform faults, which has the effect of transforming Earth Science forever. Resistance to the new ideas is finally overcome in the late 1960s, as the theory of moving plates is established. Two scientists play a major role in quantifying the embryonic theory that is eventually dubbed ‘plate tectonics’. Dan McKenzie applies Euler’s theorem, used previously by Teddy Bullard to reconstruct the continents around the Atlantic, to the problem of plate rotations on a sphere and uses it to unravel the entire history of the Indian Ocean. Jason Morgan also wraps plate tectonics around a sphere. Tuzo Wilson introduces the idea of a fixed hotspot beneath Hawaii, an idea taken up by Jason Morgan to create an absolute reference frame for plate motions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wei Shi ◽  
Menghua Wang

AbstractThe 2019 positive Indian Ocean Dipole (IOD) event in the boreal autumn was the most serious IOD event of the century with reports of significant sea surface temperature (SST) changes in the east and west equatorial Indian Ocean. Observations of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) between 2012 and 2020 are used to study the significant biological dipole response that occurred in the equatorial Indian Ocean following the 2019 positive IOD event. For the first time, we propose, identify, characterize, and quantify the biological IOD. The 2019 positive IOD event led to anomalous biological activity in both the east IOD zone and west IOD zone. The average chlorophyll-a (Chl-a) concentration reached over ~ 0.5 mg m−3 in 2019 in comparison to the climatology Chl-a of ~ 0.3 mg m−3 in the east IOD zone. In the west IOD zone, the biological activity was significantly depressed. The depressed Chl-a lasted until May 2020. The anomalous ocean biological activity in the east IOD zone was attributed to the advection of the higher-nutrient surface water due to enhanced upwelling. On the other hand, the dampened ocean biological activity in the west IOD zone was attributed to the stronger convergence of the surface waters than that in a normal year.


2020 ◽  
Vol 125 (6) ◽  
Author(s):  
Ebenezer S. Nyadjro ◽  
Adam V. Rydbeck ◽  
Tommy G. Jensen ◽  
James G. Richman ◽  
Jay F. Shriver

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