Sediments in the Arabian Sea will be examined by an international scientific expedition led by a researcher from the University of Edinburgh to increase understanding of the natural processes of the ocean floor and establish its significance for global cycles and climate change. Robotic research platforms will be deployed on the sea floor to study deep-sea organisms and their impacts on sedimentary processes, without removing the creatures from their natural environment. Monsoons—winds that blow in opposite directions at different times of year— cause the Arabian Sea to be a site of huge productivity and create a mid-depth layer of intensely oxygen-depleted water. Production of plant life in the surface waters and subsequent transformations in underlying waters and sediments represent important terms in the global carbon, nitrogen and phosphorous cycles, which, in turn, affect climate. Fluxes of dissolved metals, nutrients and organic matter from oxygen-depleted sediments are also of potential global importance.
Although a number of scientific expeditions have visited the Arabian Sea during the past decade, the ocean floor has received little attention because of difficulties in accessing the seabed. The benthic (sedimentary) communities, which range from bacteria to surface-dwelling crabs and deeply burrowing worms, strongly influence the physical state of the sediments and a wide range of important geochemical processes because of the way they mix and irrigate the seafloor deposits. Expedition leader Dr Greg Cowie of the Geology and Geophysics Department said: “The Arabian Sea sediments form a ‘factory’ where nutrients, metals and organic matter undergo major transformations. This is especially true at depths of between 200 and 1000 metres where oxygen-depleted waters bathe the Arabian Sea’s margins. Because of the remote setting and consequent difficulty in studying organisms in their natural environment, very little information is available on the mechanisms and impacts of faunal contribution to seafloor processes. This remains a major gap in our understanding of how the sediment system functions.”
The scientific team will study conditions across the oxygen minimum zone (OMZ) on the Indus margin of the Arabian Sea, which serves as a natural laboratory. “We will carry out studies of the faunal communities under contrasting oxygen levels at sites across the OMZ, alongside detailed assessments of sediment geochemistry,” said Greg Cowie.
Platforms, known as benthic landers, will be set up on the seafloor and used for incubation experiments in which tracers will be used to examine sediment processing by benthic creatures and its impact on nutrient, metal and organic matter cycling. The information obtained will help improve our understanding of the workings of the sea-bed and their connection with geochemical cycles and climate changes. The expedition will consist of four cruises on the RRS Charles Darwin in 2003.
Linda Menzies | AlphaGalileo
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Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
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For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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