Recent Submissions

  • A Precambrian microcontinent in the Indian Ocean.

    Torsvik, Trond H.; Amundsen, Hans; Hartz, Ebbe H.; Corfu, Fernando; Kusznir, Nick; Gaina, Carmen; Doubrovine, Pavel V.; Steinberger, Bernhard; Ashwal, Lewis D.; Jamtveit, Bjørn (2013)
    The Laccadive–Chagos Ridge and Southern Mascarene Plateau in the north-central and western Indian Ocean, respectively, are thought to be volcanic chains formed above the Réunion mantle plume1 over the past 65.5 million years2,3. Here we use U–Pb dating to analyse the ages of zircon xenocrysts found within young lavas on the island of Mauritius, part of the Southern Mascarene Plateau. We find that the zircons are either Palaeoproterozoic (more than 1,971 million years old) or Neoproterozoic (between 660 and 840 million years old). We propose that the zircons were assimilated from ancient fragments of continental lithosphere beneath Mauritius, and were brought to the surface by plume-related lavas. We use gravity data inversion to map crustal thickness and find that Mauritius forms part of a contiguous block of anomalously thick crust that extends in an arc northwards to the Seychelles. Using plate tectonic reconstructions, we show that Mauritius and the adjacent Mascarene Plateau may overlie a Precambrian microcontinent that we call Mauritia. On the basis of reinterpretation of marine geophysical data4, we propose that Mauritia was separated from Madagascar and fragmented into a ribbon-like configuration by a series of mid-ocean ridge jumps during the opening of the Mascarene ocean basin between 83.5 and 61 million years ago.We suggest that the plume-related magmatic deposits have since covered Mauritia and potentially other continental fragments.
  • New Indian Ocean Program Builds on a Scientific Legacy.

    Hood, R,R,; McPhaden, M.J.; Urban, E. (2014)
    Prior to the International Geophysical Year (1957–1958) and before the acceptance of ideas about continental drift and the emergence of the theory of plate tectonics, the Indian Ocean was viewed as one of the last great frontiers of Earth exploration. During this post–World War II era, many new technologies were emerging for sampling the ocean and atmosphere and for mapping deep- ocean topography. Yet fundamental descriptive work still remained to be done on oceanic and atmospheric circulation, marine geology, and biological and ecological variability in the Indian Ocean. Motivated by these technological developments and the opportunity to explore one of the last great frontiers on Earth, the Scientific Committee on Ocean Research (SCOR) and the Intergovernmental Oceanographic Commission (IOC) launched one of the greatest oceanographic expeditions of all time: the International Indian Ocean Expedition (IIOE). An interdisciplinary endeavor embracing physical oceanography, chemical oceanography, marine biology, meteorology, and marine geology and geophysics, IIOE was a monumental mid- twentieth- century oceanographic research program that conducted an unprecedented number of hydrographic surveys covering the entire Indian Ocean basin
  • Pacific origin of the abrupt increase in Indian Ocean heat content during the warming hiatus. [and Supplementary Information]

    Lee, Sang-Ki; Park, Wonsun; Baringer, Molly O.; Gordon, Arnold L.; Huber, Bruce; Liu, Yanyun (2015)
    Global mean surface warming has stalled since the end of the twentieth century1,2, but the net radiation imbalance at the top of the atmosphere continues to suggest an increasingly warming planet. This apparent contradiction has been reconciled by an anomalous heat flux into the ocean3–8, induced by a shift towards a La Niña-like state with cold sea surface temperatures in the eastern tropical Pacific over the past decade or so. A significant portion of the heat missing fromthe atmosphere is therefore expected to be stored in the Pacific Ocean. However, in situ hydrographic records indicate that Pacific Ocean heat content has been decreasing9. Here, we analyse observations along with simulations from a global ocean–sea ice model to track the pathway of heat. We find that the enhanced heat uptake by the Pacific Ocean has been compensated by an increased heat transport from the Pacific Ocean to the Indian Ocean, carried by the Indonesian throughflow. As a result, Indian Ocean heat content has increased abruptly, which accounts for more than 70% of the global ocean heat gain in the upper 700m during the past decade. We conclude that the Indian Ocean has become increasingly important in modulating global climate variability.
  • Indian Ocean - RAMA Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction: Journal publications. [Webpage]

    Pacific Marine Environmental Laboratory, NOAA (2017)
    The Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction (RAMA) was designed to study the Indian Ocean’s role in the monsoons. One third of the world population depends on monsoon driven rainfall for agricultural production, so improving our understanding and ability to predict the monsoons has been a longstanding objective of the international scientific community. RAMA, the newest tropical buoy array, was initiated in the traditionally data sparse Indian Ocean in 2004 following deployment of successful pilot scale arrays by Japan and India. RAMA has since grown through the formation of new partnerships that at present include Indonesia, China, the USA, and the Bay of Bengal Large Marine Ecosystem (BOBLME) program.
  • The 2nd International Indian Ocean Expedition (IIOE-2): Motivating New Exploration in a Poorly Understood Basin.

    Hood, Raleigh; Urban, Edward R.; McPhaden, Michael J.; Su, Danielle; Raes, Eric (Association for the Sciences of Limnology and Oceanography (ASLO), 2016)
    The Indian Ocean remains one of the most poorly sampled and overlooked regions of the world ocean. Today, more than 25% of the world’s population lives in the Indian Ocean region and the population of most Indian Ocean rim nations is increasing rapidly. These increases in population are giving rise to multiple stressors in both coastal and open ocean environments. Combined with warming and acidification due to global climate change, these regional stressors are resulting in loss of biodiversity in the Indian Ocean and also changes in the phenology and biogeography of many species. These pressures have given rise to an urgent need to understand and predict changes in the Indian Ocean, but the measurements that are needed to do this are still lacking. In response, SCOR, IOC, and IOGOOS have stimulated a second International Indian Ocean Expedition (IIOE-2). An international Science Plan and an Implementation Strategy for IIOE-2 have been developed, the formulation of national plans is well underway in several countries, and new research initiatives are being motivated
  • Perspectives on future Indian Ocean research from early career scientists: report on a Workshop for early carrier scientists conducted during the International Symposium on the Indian Ocean at National Institute of Oceanography, Goa on 2 December 2015.

    Singh, Arvind; al, et (2016)
    The 2015 International IO Symposium held at the National Institute of Oceanography (NIO), Goa, India, marked the launch of the Second International Indian Ocean expedition (henceforth, IIOE2) that will be conducted between 2015 and 2020 (http://www.iioe-2.incois.gov.in/). It is an exciting time and opportunity for marine science throughout the IO, especially for early career scientists. The next decade will be a time to push the frontiers of scientific discoveries through multidisciplinary and collaborative approaches. With the goal to give further impetus to marine science in the IO, the Early Career Scientist Workshop was conducted during the symposium. Over 50 early career scientists and academic mentors came together and identified key research topics and knowledge gaps that will be subjected to research during IIOE2 in general and the IIOE2