| 1. |
- Best, Mairi, et al.
(författare)
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EMSO: A distributed infrastructure for addressing geohazards and global ocean change
- 2014
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Ingår i: Oceanography. - : The Oceanography Society. - 1042-8275. ; 27:2, s. 167-169
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Tidskriftsartikel (refereegranskat)abstract
- The European Multidisciplinary Seafloor and water-column Observatory (EMSO; http://www.emso-eu.org) is addressing the next challenge in Earth-ocean science: how to coordinate data acquisition, analysis, archiving, access, and response to geohazards across provincial, national, regional, and international boundaries. Such coordination is needed to optimize the use of current and planned ocean observatory systems to (1) address national and regional public safety concerns about geohazards (e.g., earthquakes, submarine landslides, tsunamis) and (2) permit broadening of their scope toward monitoring environmental change on global ocean scales.
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| 2. |
- Best, Mairi M. R., et al.
(författare)
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The EMSO-ERIC Pan-European Consortium: Data Benefits and Lessons Learned as the Legal Entity Forms
- 2016
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Ingår i: Marine Technology Society journal. - 0025-3324. ; 50:3, s. 8-15
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Tidskriftsartikel (refereegranskat)abstract
- The European Multidisciplinary Seafloor and water-column Observatory (EMSO) European Research Infrastructure Consortium (ERIC) provides power, communications, sensors, and data infrastructure for continuous, high-resolution, (near-)real-time, interactive ocean observations across a multidisciplinary and interdisciplinary range of research areas including biology, geology, chemistry, physics, engineering, and computer science, from polar to subtropical environments, through the water column down to the abyss. Eleven deep-sea and four shallow nodes span from the Arctic through the Atlantic and Mediterranean, to the Black Sea. Coordination among the consortium nodes is being strengthened through the EMSOdev project (H2020), which will produce the EMSO Generic Instrument Module (EGIM). Early installations are now being upgraded, for example, at the Ligurian, Ionian, Azores, and Porcupine Abyssal Plain (PAP) nodes. Significant findings have been flowing in over the years; for example, high-frequency surface and subsurface water-column measurements of the PAP node show an increase in seawater pCO2 (from 339 μatm in 2003 to 353 μatm in 2011) with little variability in the mean air-sea CO2 flux. In the Central Eastern Atlantic, the Oceanic Platform of the Canary Islands open-ocean canary node (aka ESTOC station) has a long-standing time series on water column physical, biogeochemical, and acidification processes that have contributed to the assessment efforts of the Intergovernmental Panel on Climate Change (IPCC). EMSO not only brings together countries and disciplines but also allows the pooling of resources and coordination to assemble harmonized data into a comprehensive regional ocean picture, which will then be made available to researchers and stakeholders worldwide on an open and interoperable access basis.
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| 3. |
- Haalboom, Sabine, et al.
(författare)
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Monitoring of Anthropogenic Sediment Plumes in the Clarion-Clipperton Zone, NE Equatorial Pacific Ocean
- 2022
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Ingår i: Frontiers in Marine Science. - 2296-7745. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The abyssal seafloor in the Clarion-Clipperton Zone (CCZ) in the NE Pacific hosts the largest abundance of polymetallic nodules in the deep sea and is being targeted as an area for potential deep-sea mining. During nodule mining, seafloor sediment will be brought into suspension by mining equipment, resulting in the formation of sediment plumes, which will affect benthic and pelagic life not naturally adapted to any major sediment transport and deposition events. To improve our understanding of sediment plume dispersion and to support the development of plume dispersion models in this specific deep-sea area, we conducted a small-scale, 12-hour disturbance experiment in the German exploration contract area in the CCZ using a chain dredge. Sediment plume dispersion and deposition was monitored using an array of optical and acoustic turbidity sensors and current meters placed on platforms on the seafloor, and by visual inspection of the seafloor before and after dredge deployment. We found that seafloor imagery could be used to qualitatively visualise the redeposited sediment up to a distance of 100 m from the source, and that sensors recording optical and acoustic backscatter are sensitive and adequate tools to monitor the horizontal and vertical dispersion of the generated sediment plume. Optical backscatter signals could be converted into absolute mass concentration of suspended sediment to provide quantitative data on sediment dispersion. Vertical profiles of acoustic backscatter recorded by current profilers provided qualitative insight into the vertical extent of the sediment plume. Our monitoring setup proved to be very useful for the monitoring of this small-scale experiment and can be seen as an exemplary strategy for monitoring studies of future, upscaled mining trials. We recommend that such larger trials include the use of AUVs for repeated seafloor imaging and water column plume mapping (optical and acoustical), as well as the use of in-situ particle size sensors and/or particle cameras to better constrain the effect of suspended particle aggregation on optical and acoustic backscatter signals.
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| 4. |
- White, Martin, et al.
(författare)
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BENTHIC BOUNDARY LAYER CHARACTERISTICS IN CONTRASTING COLD-WATER CORAL ECOSYSTEMS
- 2008
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Ingår i: 4th International Symposium on Deep-Sea Corals, Wellington, New Zealand, December 2008.
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Konferensbidrag (refereegranskat)abstract
- B io lo g y : F ee d in g , G ro w th a nd R ep ro du c t io n Dynamics within the bottom boundary layer (BBL) are fundamental to the control of the overall benthic ecosystem functioning through processes of organic matter fluxes, turbulence, seabed frictional stresses, and re-suspension processes. Observations of BBL structure using high frequency HF-ADCPs have been made to estimate the frictional stresses within, and adjacent to, coral reef habitats. Measurements at the Tisler Reef, Skagerrak, both in and outside the coral reef have shown that the logarithmic layer approach to estimating bottom stresses can be used and is comparable to directly measured Reynolds stress measurements. Outside regions of live coral clumps, where the seabed is characterised by rubble material, friction velocities (u *, which determines the bottom stress, τ=ρ.u * 2 ) may reach values up to 2 cm s-1 with a mean of 1 cm s-1. A corresponding roughness length, characterising the boundary layer height generated by the seabed, is 2 cm. In contrast, within localized live coral stands, a higher BBL is generated with a roughness length scale of 50 cm and higher friction velocity – a mean of 2.5 cm s-1 and maximum of 5 cm s-1. Interestingly the friction velocities generated by the live reef are higher than those in a rubble area for any particular impinging flow speed, as a result of the greater turbulence generated by the larger bottom topography of the live reef system. This may result in an increased time period for particles to remain in suspension over a reef system compared to other seabed environments. The measurements have been contrasted to those made at a deep carbonate mound located west of Ireland. Here, two bottom landers equipped with HF-ADCPs were deployed near the summit of a mound and in the adjacent gully between two mounds. Boundary layer characteristics in the gully region are similar to those found in the rubble region for the Tisler reef measurements. Measurements near the mound summit indicated higher frictional velocities present compared to the gulley region, again similar to the shallow water observations. The values of frictional velocity generated per impinging flow speed, however, fall between those found for the Tisler observations in and outside the reef, reflecting the bottom topography, which consisted of smaller scale, and more widely dispersed, coral clumps than at the Tisler reef. The results have obvious implications for the fluxes of organic mater, material suspension (availability) and feeding behavior at a coral ecosystem and we suggest they require inclusion into micro habitat mapping and reef growth models.
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