30 results on '"Spiegel, Timo"'
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2. Updated estimates of sedimentary potassium sequestration and phosphorus release on the Amazon shelf
- Author
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Spiegel, Timo, Vosteen, Paul, Wallmann, Klaus, Paul, Sophie A.L., Gledhill, Martha, and Scholz, Florian
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- 2021
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3. Provenance of clay-sized detrital sediments in the North Sea and the Skagerrak region based on radiogenic Nd-Sr-Hf isotopes and clay mineral compositions: Assessing the impact of coastal and seabed erosion
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Lenz, Nina, Spiegel, Timo, Hathorne, Ed, Wallmann, Klaus, Eisenhauer, Anton, Frank, Martin, Lenz, Nina, Spiegel, Timo, Hathorne, Ed, Wallmann, Klaus, Eisenhauer, Anton, and Frank, Martin
- Abstract
The Skagerrak basin represents the main sink area for fine-grained sediment in the North Sea region and constitutes a natural deposition centre for sediments that are supplied from the Atlantic, the Baltic Sea and the surrounding continental margins and coasts. However, the exact sources and their proportional contributions to the North Sea sediments and to the Skagerrak deposits are not well understood.To trace the predominant sources of the sediment and to gain a better understanding of the sedimentary processes in the North Sea and the Skagerrak basin, radiogenic Sr, Nd, and Hf isotope signatures and clay mineral compositions of the detrital clay fraction of surface sediment samples from the North Sea, the Scandinavian margins and the Baltic Sea were measured.The results indicate that the major source for Skagerrak clay-size sediments is the northern North Sea but Scandinavia as well as the southern North Sea including the southern England coast also contribute material. Seabed and coastal erosion in the northern North Sea are enhanced by the inflowing Atlantic Currents, which provide the Skagerrak with high amounts of clay size sediments. In contrast, the southern North Sea, the Baltic Sea and mid-European rivers such as Weser, Elbe and Ems are only minor contributors. As Skagerrak deposits are dominated by clay sized material (up to 60%), the reconstructed sediment processes related to this study deviate from findings in previous sediment budget studies, which were based on both clay and silt fraction and indicated predominant influences from the southern North Sea. These results highlight that coastal and seabed erosion in the North Sea is a previously underestimated source of fine-grained sediments for depocenters in the entire North Sea.With regard to climate change, the global sea-level rise will likely enhance erosional processes and can therefore significantly influence the sediment budget of the entire North Sea.
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- 2024
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4. Patterns and dynamics of sedimentation and biogeochemical processes in the Skagerrak
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Spiegel, Timo and Spiegel, Timo
- Abstract
The North Sea represents a major sink for atmospheric carbon dioxide (CO2) from anthropogenic emissions. However, the North Sea sediment and carbon cycles have been heavily affected by human activities during the last century. In particular, frequent resuspension of sedimentary particulate organic carbon (POC) by bottom trawling, dredging or wind farm constructions might reduce POC burial and, consequently, reduce the CO2 sequestration potential of the North Sea. The Skagerrak serves as the largest depocenter for sediments and POC in the North Sea. Hence, Skagerrak deposits provide a historical record of how the North Sea ecosystem has changed over time. This thesis revisits sedimentation and biogeochemical processes in the Skagerrak based on a combination of solid phase and porewater geochemistry, in-situ measurements and modeling. Highly resolved temporal and spatial data are used to better characterize the benthic sediment, POC and biogenic silica (bSi) cycles in the Skagerrak and to track the impact of human and natural processes in the North Sea over the past ~100 years. A major finding of this thesis reveals that average sedimentation rates and POC burial fluxes substantially decreased from before to after the year 1963 in the Skagerrak. Possible explanations involve a shift in the North Sea circulation pattern and increasing POC settling in other depocenters of the North Sea, such as the Wadden Sea. Hence, deposition rates in the Skagerrak are likely dominated by these processes rather than by the effect of sediment resuspension caused by human activities on deposition rates in the Skagerrak. In order to assess the spatial variability of sedimentation processes in the Skagerrak, a machine learning model is used to upscale compiled datasets to areawide spatial distributions of porosities, mass accumulation rates (MAR) and lead-210 (210Pb) rain rates in the Skagerrak. The spatial distributions reveal areas of elevated 210Pb rain rates and MAR at intermediate wa
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- 2024
5. Alkaline mineral addition to anoxic to hypoxic Baltic Sea sediments as a potentially efficient CO2-removal technique
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Fuhr, Michael, Wallmann, Klaus, Dale, Andrew W., Kalapurakkal, Habeeb Thanveer, Schmidt, Mark, Sommer, Stefan, Deusner, Christian, Spiegel, Timo, Kowalski, Jannes, Geilert, Sonja, Fuhr, Michael, Wallmann, Klaus, Dale, Andrew W., Kalapurakkal, Habeeb Thanveer, Schmidt, Mark, Sommer, Stefan, Deusner, Christian, Spiegel, Timo, Kowalski, Jannes, and Geilert, Sonja
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- 2024
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6. A look into the temporal variability of sedimentation rates in the Skagerrak to track human and natural impacts in the North Sea
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Wolschke, Hendrik, Müller, Daniel, Butzin, Martin, Dale, Andrew W., Kasten, Sabine, Schmidt, Mark, Moros, Matthias, Fuhr, Michae, Wallmann, Klaus, Spiegel, Timo, Lenz, Nina, Lindhorst, Sebastian, Kalapurakkal, Habeeb Thanveer, Wolschke, Hendrik, Müller, Daniel, Butzin, Martin, Dale, Andrew W., Kasten, Sabine, Schmidt, Mark, Moros, Matthias, Fuhr, Michae, Wallmann, Klaus, Spiegel, Timo, Lenz, Nina, Lindhorst, Sebastian, and Kalapurakkal, Habeeb Thanveer
- Published
- 2024
7. Modelling mass accumulation rates and 210Pb rain rates in the Skagerrak: lateral sediment transport dominates the sediment input
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Spiegel, Timo, Diesing, Markus, Dale, Andrew W., Lenz, Nina, Schmidt, Mark, Sommer, Stefan, Böttner, Christoph, Fuhr, Michael, Kalapurakkal, Habeeb Thanveer, Schulze, Cosima-S., Wallmann, Klaus, Spiegel, Timo, Diesing, Markus, Dale, Andrew W., Lenz, Nina, Schmidt, Mark, Sommer, Stefan, Böttner, Christoph, Fuhr, Michael, Kalapurakkal, Habeeb Thanveer, Schulze, Cosima-S., and Wallmann, Klaus
- Abstract
Sediment fluxes to the seafloor govern the fate of elements and compounds in the ocean and serve as a prerequisite for research on elemental cycling, benthic processes and sediment management strategies. To quantify these fluxes over seafloor areas, it is necessary to scale up sediment mass accumulation rates (MAR) obtained from multiple sample stations. Conventional methods for spatial upscaling involve averaging of data or spatial interpolation. However, these approaches may not be sufficiently precise to account for spatial variations of MAR, leading to poorly constrained regional sediment budgets. Here, we utilize a machine learning approach to scale up porosity and 210 Pb data from 145 and 65 stations, respectively, in the Skagerrak. The models predict the spatial distributions by considering several predictor variables that are assumed to control porosity and 210 Pb rain rates. The spatial distribution of MAR is based on the predicted porosity and existing sedimentation rate data. Our findings reveal highest MAR and 210 Pb rain rates to occur in two parallel belt structures that align with the general circulation pattern in the Skagerrak. While high 210 Pb rain rates occur in intermediate water depths, the belt of high MAR is situated closer to the coastlines due to lower porosities at shallow water depths. Based on the spatial distributions, we calculate a total MAR of 34.7 Mt yr -1 and a 210 Pb rain rate of 4.7 · 10 14 dpm yr -1 . By comparing atmospheric to total 210 Pb rain rates, we further estimate that 24% of the 210 Pb originates from the local atmospheric input, with the remaining 76% being transported laterally into the Skagerrak. The updated MAR in the Skagerrak is combined with literature data on other major sediment sources and sinks to present a tentative sediment budget for the North Sea, which reveals an imbalance with sediment outputs exceeding the inputs. Substantial uncertainties in the revised Skagerrak MAR and the literature data might clo
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- 2024
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8. Alkaline mineral addition to anoxic to hypoxic Baltic Sea sediments as a potentially efficient CO2-removal technique
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Geochemistry, IVAU: Instituut voor Aardwetenschappen Utrecht, Fuhr, Michael, Wallmann, Klaus, Dale, Andrew W., Kalapurakkal, Habeeb Thanveer, Schmidt, Mark, Sommer, Stefan, Deusner, Christian, Spiegel, Timo, Kowalski, Jannes, Geilert, Sonja, Geochemistry, IVAU: Instituut voor Aardwetenschappen Utrecht, Fuhr, Michael, Wallmann, Klaus, Dale, Andrew W., Kalapurakkal, Habeeb Thanveer, Schmidt, Mark, Sommer, Stefan, Deusner, Christian, Spiegel, Timo, Kowalski, Jannes, and Geilert, Sonja
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- 2024
9. Modelling mass accumulation rates and 210Pb rain rates in the Skagerrak: lateral sediment transport dominates the sediment input
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Spiegel, Timo, primary, Diesing, Markus, additional, Dale, Andrew W., additional, Lenz, Nina, additional, Schmidt, Mark, additional, Sommer, Stefan, additional, Böttner, Christoph, additional, Fuhr, Michael, additional, Kalapurakkal, Habeeb Thanveer, additional, Schulze, Cosima-S., additional, and Wallmann, Klaus, additional
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- 2024
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10. Alkaline mineral addition to anoxic to hypoxic Baltic Sea sediments as a potentially efficient CO2-removal technique
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Fuhr, Michael, primary, Wallmann, Klaus, additional, Dale, Andrew W., additional, Kalapurakkal, Habeeb Thanveer, additional, Schmidt, Mark, additional, Sommer, Stefan, additional, Deusner, Christian, additional, Spiegel, Timo, additional, Kowalski, Jannes, additional, and Geilert, Sonja, additional
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- 2024
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11. Modelling mass accumulation rates and 210Pb rain rates in the Skagerrak: lateral sediment transport dominates the sediment input.
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Spiegel, Timo, Diesing, Markus, Dale, Andrew W., Lenz, Nina, Schmidt, Mark, Sommer, Stefan, Böttner, Christoph, Fuhr, Michael, Kalapurakkal, Habeeb Thanveer, Schulze, Cosima-S., and Wallmann, Klaus
- Subjects
RAINFALL ,SEDIMENT transport ,SUSPENDED sediments ,INDEPENDENT variables ,WATER depth ,EROSION - Abstract
Sediment fluxes to the seafloor govern the fate of elements and compounds in the ocean and serve as a prerequisite for research on elemental cycling, benthic processes and sediment management strategies. To quantify these fluxes over seafloor areas, it is necessary to scale up sediment mass accumulation rates (MAR) obtained from multiple sample stations. Conventional methods for spatial upscaling involve averaging of data or spatial interpolation. However, these approaches may not be sufficiently precise to account for spatial variations of MAR, leading to poorly constrained regional sediment budgets. Here, we utilize a machine learning approach to scale up porosity and
210 Pb data from 145 and 65 stations, respectively, in the Skagerrak. The models predict the spatial distributions by considering several predictor variables that are assumed to control porosity and210 Pb rain rates. The spatial distribution of MAR is based on the predicted porosity and existing sedimentation rate data. Our findings reveal highest MAR and210 Pb rain rates to occur in two parallel belt structures that align with the general circulation pattern in the Skagerrak. While high210 Pb rain rates occur in intermediate water depths, the belt of high MAR is situated closer to the coastlines due to lower porosities at shallow water depths. Based on the spatial distributions, we calculate a total MAR of 34.7 Mt yr-1 and a210 Pb rain rate of 4.7 · 1014 dpm yr-1 . By comparing atmospheric to total210 Pb rain rates, we further estimate that 24% of the210 Pb originates from the local atmospheric input, with the remaining 76% being transported laterally into the Skagerrak. The updated MAR in the Skagerrak is combined with literature data on other major sediment sources and sinks to present a tentative sediment budget for the North Sea, which reveals an imbalance with sediment outputs exceeding the inputs. Substantial uncertainties in the revised Skagerrak MAR and the literature data might close this imbalance. However, we further hypothesize that previous estimates of suspended sediment inputs into the North Sea might have been underestimated, considering recently revised and elevated estimates on coastal erosion rates in the surrounding region of the North Sea. [ABSTRACT FROM AUTHOR]- Published
- 2024
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12. Drivers of pelagic and benthic microbial communities on Central Arctic seamounts
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von Jackowski, Anabel, primary, Walter, Maren, additional, Spiegel, Timo, additional, Buttigieg, Pier Luigi, additional, and Molari, Massimiliano, additional
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- 2023
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13. Biogenic silica cycling in the Skagerrak
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Spiegel, Timo, primary, Dale, Andrew W., additional, Lenz, Nina, additional, Schmidt, Mark, additional, Sommer, Stefan, additional, Kalapurakkal, Habeeb Thanveer, additional, Przibilla, Anna, additional, Lindhorst, Sebastian, additional, and Wallmann, Klaus, additional
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- 2023
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14. Biogenic silica cycling in the Skagerrak
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Spiegel, Timo, Dale, Andrew W., Lenz, Nina, Schmidt, Mark, Sommer, Stefan, Kalapurakkal, Habeeb Thanveer, Przibilla, Anna, Lindhorst, Sebastian, Wallmann, Klaus, Spiegel, Timo, Dale, Andrew W., Lenz, Nina, Schmidt, Mark, Sommer, Stefan, Kalapurakkal, Habeeb Thanveer, Przibilla, Anna, Lindhorst, Sebastian, and Wallmann, Klaus
- Published
- 2023
15. Impact of bottom trawling on long-term carbon sequestration in shelf sea sediments
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Zhang, Wenyan, Porz, Lucas, Yilmaz, Rümeysa, Kuhlmann, Jannis, Neumann, Andreas, Liu, Bo, Müller, Daniel, Spiegel, Timo, Holtappels, Moritz, Ziebarth, Nadja, Taylor, Bettins, Wallmann, Klaus, Kasten, Sabine, Daewel, Ute, Schrum, Corinna, Zhang, Wenyan, Porz, Lucas, Yilmaz, Rümeysa, Kuhlmann, Jannis, Neumann, Andreas, Liu, Bo, Müller, Daniel, Spiegel, Timo, Holtappels, Moritz, Ziebarth, Nadja, Taylor, Bettins, Wallmann, Klaus, Kasten, Sabine, Daewel, Ute, and Schrum, Corinna
- Abstract
Bottom trawling represents the most widespread anthropogenic physical disturbance to shelf sea sediments. While trawling-induced mortality in benthic fauna has been extensively investigated, its impacts on ecosystem functioning and carbon cycling at regional scales remain unclear. Using the North Sea as an example, we address these issues by synthesizing a high-resolution dataset of bottom trawling impact on sediments, feeding this dataset into a 3-dimensional physical–biogeochemical model to estimate trawling-induced changes in biomass, bioturbation and sedimentary organic carbon, and assessing model results with field samples. Results suggest a trawling-induced net reduction in macrobenthic biomass by 10-27%. Trawling-induced resuspension and reduction of bioturbation jointly and accumulatively reduce the regional sedimentary organic carbon sequestration capacity by 21-67%, equivalent to 0.58-1.84 Mt CO2 yr-1. Our study emphasizes the need for proper management of trawling on muddy seabeds, if the natural capacity of shelf seas for carbon sequestration should be conserved and restored.
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- 2023
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16. Drivers of pelagic and benthic microbial communities on Central Arctic seamounts
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von Jackowski, Anabel, Walter, Maren, Spiegel, Timo, Buttigieg, Pier Luigi, Molari, Massimiliano, von Jackowski, Anabel, Walter, Maren, Spiegel, Timo, Buttigieg, Pier Luigi, and Molari, Massimiliano
- Abstract
Seamounts are abundant features on the seafloor that serve as hotspots and barriers for the dispersal of benthic organisms. The primary focus of seamount ecology has typically been on the composition and distribution of faunal communities, with far less attention given to microbial communities. Here, we investigated the microbial communities in the water column (0-3400 m depth) and sediments (619-3883 m depth, 0-16 cm below seafloor) along the ice-covered Arctic ridge system called the Langseth Ridge. We contextualized the microbial community composition with data on the benthic trophic state (i.e., organic matter, chlorophyll- a content, and porewater geochemistry) and substrate type (i.e., sponge mats, sediments, basaltic pebbles). Our results showed slow current velocities throughout the water column, a shift in the pelagic microbial community from a dominance of Bacteroidia in the 0-10 m depth towards Proteobacteria and Nitrososphaeria below the epipelagic zone. In general, the pelagic microbial communities showed a high degree of similarity between the Langseth Ridge seamounts to a northern reference site. The only notable differences were decreases in richness between ~600 m and the bottom waters (~10 m above the seafloor) that suggest a pelagic-benthic coupling mediated by filter feeding of sponges living on the seamount summits. On the seafloor, the sponge spicule mats, and polychaete worms were the principal source of variation in sedimentary biogeochemistry and the benthic microbial community structure. The porewater signature suggested that low organic matter degradation rates are accompanied by a microbial community typical of deep-sea oligotrophic environments, such as Proteobacteria, Acidimicrobiia, Dehalococcoidia, Nitrospira, and archaeal Nitrososphaeria. The combined analysis of biogeochemical parameters and the microbial community suggests that the sponges play a significant role for pelagic-benthic coupling and acted as ecosystem engineers on the
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- 2023
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17. Impact of bottom trawling on long-term carbon sequestration in shelf sea sediments
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Zhang, Wenyan, primary, Porz, Lucas, additional, Yilmaz, Rümeysa, additional, Kuhlmann, Jannis, additional, Neumann, Andreas, additional, Liu, Bo, additional, Müller, Daniel, additional, Spiegel, Timo, additional, Holtappels, Moritz, additional, Ziebarth, Nadja, additional, Taylor, Bettins, additional, Wallmann, Klaus, additional, Kasten, Sabine, additional, Daewel, Ute, additional, and Schrum, Corinna, additional
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- 2023
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18. Reconstruction of the provenance of detrital sediments in the Skagerrak region by using radiogenic Nd-Sr-Hf isotopes and clay mineral compositions
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Lenz, Nina, primary, Spiegel, Timo, additional, Hathorne, Ed, additional, Wallmann, Klaus, additional, and Frank, Martin, additional
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- 2023
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19. The Fate of Sedimentary Reactive Iron at the Land‐Ocean Interface: A Case Study From the Amazon Shelf
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Vosteen, Paul, primary, Spiegel, Timo, additional, Gledhill, Martha, additional, Frank, Martin, additional, Zabel, Matthias, additional, and Scholz, Florian, additional
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- 2022
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20. The Fate of Sedimentary Reactive Iron at the Land‐Ocean Interface:A Case Study from the Amazon Shelf
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Vosteen, Paul, Spiegel, Timo, Gledhill, Martha, Frank, Martin, Zabel, Matthias, Scholz, Florian, Vosteen, Paul, Spiegel, Timo, Gledhill, Martha, Frank, Martin, Zabel, Matthias, and Scholz, Florian
- Abstract
Reactive iron (Fe) oxides in marine sediments may represent a source of bioavailable Fe to the ocean via reductive dissolution and sedimentary Fe release or can promote organic carbon preservation and long-term burial. Furthermore, enrichments of reactive Fe (sum of Fe oxides, carbonates and sulfides normalized to total Fe) in ancient sediments are utilized as a paleo-proxy for anoxic conditions. Considering the general importance of reactive Fe oxides in marine biogeochemistry, it is important to quantify their terrestrial sources and fate at the land-ocean interface. We applied sequential Fe extractions to sediments from the Amazon shelf to investigate the transformation of river-derived Fe oxides during early diagenesis. We found that ∼22 % of the Amazon River-derived Fe oxides are converted to Fe-containing clay minerals in Amazon shelf sediments. The incorporation of reactive Fe into authigenic clay minerals (commonly referred to as reverse weathering) is substantiated by the relationship between Fe oxide loss and potassium (K) uptake from sedimentary pore waters, which is in agreement with the previously reported Fe/K stoichiometry of authigenic clay minerals. Mass balance calculations suggest that widely applied sequential extractions do not separate Fe-rich authigenic clay minerals from reactive Fe oxides and carbonates. We conclude that the balance between terrestrial supply of reactive Fe and reverse weathering in continental margin sediments has to be taken into account in the interpretation of sedimentary Fe speciation data. Key Points - Reactive Fe is transferred from river-derived Fe oxides into Fe-containing silicate minerals during early diagenesis - Standard sequential extraction schemes do not separate Fe oxides and carbonates from authigenic silicate minerals in Amazon shelf sediments - Terrigenous supply of reactive Fe and reverse weathering need to be considered in the interpretation of sedimentary Fe speciation
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- 2022
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21. Wave induced pockmark formation in the North Sea, Cruise No. MSM 99/2 (GPF 21-1_013), 26.03.2021 - 05.04.2021, Emden (Germany) - Emden (Germany). HELGOLAND POCKMARKS
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Schmidt, Christopher, Böttner, Christoph, Schmidt, Mark, Müller, Thomas Harald, Wünsche, Anna, Willems, Tim, Lindner, Marie, Müller, Frieda, Hunkemöller, Annette, and Spiegel, Timo
- Published
- 2021
22. Dynamics and variability of POC burial in depocenters of the North Sea (Skagerrak), Cruise No. AL561, 2.08.2021 – 13.08.2021, Kiel – Kiel, APOC
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Schmidt, Mark, Sommer, Stefan, Böttner, Christoph, Dale, Andrew W., Lenz, Nina, Spiegel, Timo, Schmidt, Mark, Sommer, Stefan, Böttner, Christoph, Dale, Andrew W., Lenz, Nina, and Spiegel, Timo
- Abstract
The AL561 cruise was conducted in the framework of the project APOC (“Anthropogenic impacts on Particulate Organic Carbon cycling in the North Sea”). This collaborative project between GEOMAR, AWI, HEREON, UHH, and BUND is to understand how particulate organic carbon (POC) cycling contributes to carbon sequestration in the North Sea and how this ecosystem service is compromised and interlinked with global change and a range of human pressures include fisheries (pelagic fisheries, bottom trawling), resource extraction (sand mining), sediment management (dredging and disposal of dredged sediments) and eutrophication. The main aim of the sampling activity during AL561 cruise was to recover undisturbed sediment from high accumulation sites in the Skagerrak/Kattegat and to subsample sediment/porewater at high resolution in order to investigate sedimentation transport processes, origin of sediment/POC and mineralization processes over the last 100- 200 years. Moreover, the actual processes of sedimentation and POC degradation in the water column and benthic layer will be addressed by sampling with CTD and Lander devices. In total 9 hydroacoustic surveys (59 profiles), 4 Gravity Corer, 7 Multicorer, 3 Lander and 4 CTD stations were successfully conducted during the AL561 cruise.
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- 2021
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23. RV SONNE Fahrtbericht / Cruise Report SO277 OMAX: Offshore Malta Aquifer Exploration, Emden (Germany) – Emden (Germany), 14.08. – 03.10.2020
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Berndt, Christian, Urlaub, Morelia, Jegen, Marion, Faghih, Zahra, Reeck, Konstantin, Franz, Gesa, Barnscheidt, Kim Carolin, Wollatz-Vogt, Martin, Liebsch, Jonas, Schramm, Bettina, Elger, Judith, Kühn, Michel, Müller, Thomas, Schmidt, Mark, Spiegel, Timo, Timm, Henrike, Hinz, Anina-Kaja, Sager, Thore, Hilbert, Helene-Sophie, Rohde, Lea, Korbjuhn, Torge, Reissmann, Silvia, Diller, Nikolaj, Berndt, Christian, Urlaub, Morelia, Jegen, Marion, Faghih, Zahra, Reeck, Konstantin, Franz, Gesa, Barnscheidt, Kim Carolin, Wollatz-Vogt, Martin, Liebsch, Jonas, Schramm, Bettina, Elger, Judith, Kühn, Michel, Müller, Thomas, Schmidt, Mark, Spiegel, Timo, Timm, Henrike, Hinz, Anina-Kaja, Sager, Thore, Hilbert, Helene-Sophie, Rohde, Lea, Korbjuhn, Torge, Reissmann, Silvia, and Diller, Nikolaj
- Abstract
SO277 OMAX served two scientific projects. The objectives of the first project, SMART, were to develop multi-disciplinary methodologies to detect, quantify, and model offshore groundwater reservoirs in regions dominated by carbonate geology such as the Mediterranean Sea. To this end we acquired controlled-source electromagnetic, seismic, hydroacoustic, geochemical, seafloor imagery data off Malta. Preliminary evaluation of the geophysical data show that there are resisitivity anomalies that may represent offshore freshwater aquifers. The absence of evidence for offshore springs means that these aquifers would be confined and that it will be difficult to use them in a sustainable manner. The objective of the second project, MAPACT-ETNA, is to monitor the flank of Etna volcano on Sicily which is slowly deforming seaward. Here, we deployed six seafloor geodesy stations and six ocean bottom seismometers for long-term observation (1-3 years). In addition, we mapped the seafloor off Mt. Etna and off the island of Stromboli to constrain the geological processes that control volcanic flank stability.
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- 2021
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24. Geochemical processes in Amazon shelf sediments - Implications for cation in phosphorus budgets
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Spiegel, Timo and Spiegel, Timo
- Published
- 2019
25. Interactions of trace metals, DOM, and particles in the Amazon estuary and associated plume as key processes for trace metal and DOM fluxes into the Atlantic
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Koschinsky-Fritsche, Andrea, Frank, Martin, Dittmar, Thorsten, Scholten, Jan, Gledhill, Martha, Hathorne, Ed. C, Border, Evan Cooper, Spiegel, Timo, Vosteen, Paul, Mutzberg, André, Leist, Lisa, Bretschneider, Lisa, Lodeiro, Pablo, Seidel, Michael, Knoke, Melina, Heinrich, Luise, Paul, Sophie Anna Luise, Zitoun, Rebecca, Fronzek, Julia, Schneider, Alexandre Batista, Münch, Jessica, Rezende, Carlos Eduardo de, Oliveira, Bráulio Cherene Brás de, Silva Júnior, Jomar Marques da, Walter, Juline Marta, Nóbrega, Maria Soares, Carvalho, Leandro Machado de, Maguire, Clive, Rohleder, Christian, and Peireira, Almir Freire
- Subjects
Rio Amazonas ,Metais ,Matéria orgânica dissolvida (DOM) ,Oligoelementos - Published
- 2018
26. Interactions of trace metals, DOM, and particles in the Amazon estuary and associated plume as key processes for trace metal and DOM fluxes into the Atlantic, Cruise No. M147, April 19 - May 21, 2018, Las Palmas (Gran Canaria) - Bel��m (Brazil)
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Koschinsky, Andrea, Frank, Martin, Dittmar, Thorsten, Gledhill, Martha, De Rezende, Carlos, Lodeiro, Pablo, Seidel, Michael, Knoke, Melina, Paul, Sophie A. L., Zitoun, Rebecca, Heinrich, Luise, Fronzek, Julia, M��nch, Jessica, Scholten, Jan, Border, Evan Cooper, Schneider, Alexandre, De Carvalho, Leandro M., Leist, Lisa, Mutzberg, Andr��, Marques Da Silva Jr., Jomar, Cherene Bras De Oliveira, Braulio, Walter, Juline M., Soares N��brega, Maria, Bretschneider, Lisa, Hathorne, Ed C., Vosteen, Paul, Spiegel, Timo, Maguire, Clive, and Rohleder, Christian
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Earth sciences and geology ,Earth Science - Abstract
METEOR Cruise M147 (Amazon - GEOTRACES) was set to assess in detail the role of the Amazon River towards the input of trace metals and dissolved organic matter (DOM) into the Atlantic Ocean as well as the isotopic characterization of water masses and mixing processes. The cruise is an official process study for the internationally coordinated GEOTRACES program (www.geotraces.org). The main research topic is to determine the distribution and speciation of trace elements along the salinity gradients in the mixing zone of the Amazon River estuary and its freshwater plume in order to quantify their biogeochemical cycling, the riverine contribution to open the ocean metal budgets, and its interaction with DOM and particulate matter. The trace metal flux to the ocean will likely be enhanced by complexation with DOM, which competes with colloidal coagulation and sedimentation. Within this frame, important factor to be considered are trace metal associations with physically different size fractions of matter (truly dissolved, organic and inorganic colloids, particles) along the salinity gradient between the river and the ocean. Therefore, a variety of filters including ultrafiltration were used to separate the different fractions. The cruise followed the Par��, as well as the Amazon south and north outflow, along the salinity transect to the open Atlantic Ocean. Furthermore, sampling continued northwards of the Amazon plume, along the coast line of Brazil and French Guiana. In total, 74 standard stainless-steel CTD-rosette profiles, 15 trace-metal clean CTD profiles, 10 single GoFlo-bottles, 60 pumps for radium samples, 107 surface samples with the towed fish and 22 multicorer stations were conducted. With this, the river water and seawater endmembers as well as the entire mixing zone within the exclusive economic zones of Brazil and French Guiana between 6��N and 1��S were covered by sampling., METEOR-Berichte
- Published
- 2018
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27. Technology-oriented Service Engineering of Contract Logistics Providers:conception of a design model for the systematic development of technology-based logistics services
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Spiegel, Timo U., Straube, Frank, and Ludwig, André
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ddc:650 ,ddc:300 ,ddc:500 ,ddc:600 - Abstract
Gedruckt erschienen im Universitätsverlag der TU Berlin, ISBN 978-3-7983-2807-5 (ISSN 1865-3170) Um von dem Wachstum des Logistikdienstleistungsmarktes zu profitieren, sich vom harten Preiswettkampf zu lösen und Kunden nachhaltig an sich zu binden, müssen insbesondere die Anbieter komplexer, kundenindividueller Kontraktlogistikleistungen ihre Fähigkeit steigern, neue Servicekonzepte effizient zu entwickeln. Dabei stellen innovative Technologien nicht nur strategisch wichtige Hebel zur Differenzierung und Realisierung neuer Marktpotenziale, sondern auch zentrale Wandlungstreiber dar. Aus den heute festzustellenden technologischen Trends ergeben sich vollkommen neue, technologiebasierte Wertschöpfungsszenarien und ein erheblicher Veränderungsdruck für die Branche. Kontraktlogistikunternehmen, die in der Lage sind, aufkommende technologische Potenziale zu erkennen und für die eigenen Herausforderungen im Rahmen innovativer Services zu nutzen, verschaffen sich entscheidende Vorteile im Wettbewerb. Viele Anbieter, deren Erfahrungen und Kompetenzen eher auf betriebsorientierten, operativen Projekten basieren, sehen sich jedoch der Herausforderung innovationshemmender Strukturen sowie mangelnder strategischer, prozessualer und methodischer Fähigkeiten gegenüber. Der Aufbau eines proaktiven Technologie- und Innovationsmanagements setzt für sie einen grundlegenden, bis auf die Ebene der Unternehmenskultur reichenden Wandlungsprozess voraus. Die Dissertation befasst sich daher mit der Konzeption eines auf die Anforderungen von Kontraktlogistikunternehmen angepassten Gestaltungsmodells für ein technologieorientiertes Service Engineering. Dem Paradigma der anwendungsbezogenen, zweckorientierten Forschung folgend, wird den verantwortlichen Entscheidungsträgern eine Unterstützung geboten, die Strukturen und Abläufe der Dienstleistungsentwicklung so zu gestalten, dass neue Services unter Berücksichtigung innovativer oder in neuem Zusammenhang eingesetzter Technologien systematisch und erfolgreich entwickelt werden können. Im Sinne des gefolgten Logistik- und Forschungsverständnisses wird ein interdisziplinärer, ganzheitlicher Ansatz aufgebaut, der den Kunden als bestimmendes Element des Handlungskontextes einbezieht und berücksichtigt. Das methodische Vorgehen gliedert sich entsprechend der Teilziele des definierten formallogischen Forschungskonzeptes in fünf Phasen. Zur Spezifikation des praxisrelevanten Problems, zur Erfassung und Interpretation der problemrelevanten Theorien und zum Aufbau des konzeptionellen Bezugsrahmens werden systematische Literaturanalysen eingesetzt. Die anschließende Erfassung und Untersuchung des Anwendungszusammenhangs unter direkter Einbindung der Praxis erfolgt dann mit Hilfe einer Kombination quantitativer und qualitativer empirischer Methoden. So wird die kausalanalytische Fragestellung nach den in der Kontraktlogistik erfolgskritischen Gestaltungsfeldern eines technologieorientierten Service Engineerings auf Basis der Ergebnisse einer explorativen Faktorenanalyse und daran anknüpfender Regressionsanalysen beantwortet. Die Erkenntnisse der inferenzstatistischen Untersuchung werden durch eine ergänzende deskriptive Analyse unterlegt. Der qualitative Teil der Untersuchung konzentriert sich auf die Frage nach den wichtigsten Herausforderungen und Maßnahmen aus Sicht der Praxis. Methodisch wird der Forschungsschritt durch den Einsatz einer Gruppendiskussion vollzogen. Die empirisch gewonnenen Erkenntnisse werden anschließend im Rahmen eines abduktiv-konzeptionellen Schrittes bei der Ableitung des Gestaltungsmodells verwertet. Das als ganzheitlicher Managementansatz ausgelegte Gestaltungsmodell bringt mit der kulturellen und strategischen Basis sowie dem markt- und technologieorientierten Entwicklungsprozess die als wesentlich erkannten Gestaltungsfelder eines technologieorientierten Service Engineerings in der Kontraktlogistik in einen Zusammenhang. Die leitende Rolle der Dienstleistungsentwicklung und die Unterstützungsfunktion des Technologiemanagements werden durch integrierte Ablaufsystematiken verdeutlicht. Mit ihnen wird die Relevanz einer prozessorientierten Logik in den Ansatz übertragen. Der Entwurf des Gestaltungsmodells wird durch praxisgerechte Hinweise zur inhaltlichen Bearbeitung der Gestaltungsfelder ergänzt. Die im Modell verankerten Maßnahmen und Werkzeuge werden auf Grundlage definierter Erfolgskriterien abgeleitet und konzentrieren sich auf insgesamt sieben Kernbereiche. Der erarbeitete Ansatz wird abschließend kritisch unter Einbeziehung von Praxisexperten bewertet und die Voraussetzungen für seine erfolgreiche Implementierung diskutiert. Insgesamt richtet sich die Dissertation, auf die weitere Forschungsarbeiten aufbauen können, an Entscheidungsträger der Kontraktlogistik. Sie erhalten eine Hilfestellung, ihre Fähigkeit zu steigern, Marktumbrüche und neue technologische Potenziale im Rahmen einer effizienten Weiterentwicklung ihres Leistungsportfolios zu erfassen, zu bewerten und zu nutzen, um von dem technologischen Fortschritt nachhaltig profitieren zu können. If they want to stay competitive and to benefit from the growth of the logistics service market contract logistics providers have to improve their capabilities to develop new service solutions in an efficient way. In this context innovative technologies are not only an important lever to realize market potential but also strategic drivers of change. The technology trends which can be identified from today’s perspective will lead to new scenarios for value creation and will force the market actors to adapt to upcoming market conditions. Hence, companies which are able to forecast the potential of upcoming technologies and to use them to overcome their challenges and to provide innovative service concepts to their customers will gain an important advantage above their competitors. Therefore the focus of this dissertation is put on the development of a holistic and context-related management approach for the establishment of a technology-oriented service engineering at contract logistics providers. The goal is to provide support for the decision makers to create the structures and processes needed for an efficient, systematic and technology-oriented service design. According to the research design, the methodical approach is structured in five phases. The specification of the research topics, the analysis and interpretation of the problem-related theories and the design of an appropriate conceptual framework is based on systematic literature reviews. For the following analysis and description of the practical application context with direct involvement of business experts a combination of quantitative and qualitative research methods is used (explorative factor analysis, regression analysis, exploratory data analysis, group discussion and expert interviews. The utilization of these methods allows to describe the main success factors of a technology-oriented service engineering, the main challenges of the companies and hands-on measures to tackle them. The findings are used for the conceptual elaboration of the new management approach in course of an abductive research step. The holistic approach is structured in form of a design model which visualizes all relevant fields of action. On top level the model differentiates between the cultural and strategic foundation on the one hand and the market- and technology-oriented development process on the other. The technology management function is regarded as support function for the actual service design process. All described measures and tools are conceptualized and adopted with respect to specified success criteria. After its development the management approach is critically reviewed and evaluated in coordination with experts from contracts logistics companies. In summary the dissertation, which is in first line dedicated to practitioners and managers of contract logistics companies, provides an practice-oriented approach, an comprehensive overview of the relevant fields of management and points out important, unanswered questions which can be taken as motivation for further research activities.
- Published
- 2016
28. Technologien und Innovationen in der Logistik
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Siegmann, Julian, Spiegel, Timo, Durach, Christian F., Elektirikci, Seyit, Ouyeder, Ouelid, Straube, Frank, and Siegmann, Julian
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300 Sozialwissenschaften ,Logistikdienstleister ,ddc:300 ,Technologie ,600 Technik, Technologie ,Innovation ,ddc:600 ,Logistik ,Kontraktlogistik - Abstract
Zugleich gedruckt veröffentlicht im Universitätsverlag der TU Berlin unter der ISBN 978-3-7983-2597-5 und im Webshop des Universitätsverlages bestellbar: http://www.ub.tu-berlin.de/universitaetsverlag-und-hochschulschriften/verlagsprogramm/2013/technologien-und-innovationen-in-der-logistik/#c49934, Neue technologische Entwicklungen sind gleichermaßen Ursache und Wegbereiter für Innovationen in der Logistik. Technologien und Innovationen sind zudem wichtige Hebel für die Schaffung von Wettbewerbsvorteilen bei Logistikdienstleistern. Vor diesem Hintergrund behandelt diese Studie zwei inhaltliche Schwerpunkte: Zukunftstechnologien in der Logistik und Innovationsmanagement bei Logistikdienstleistern. Im Zentrum der Untersuchung stehen vor allem Kontraktlogistikdienstleister. Aber auch für deren Kunden aus Industrie und Handel können die Ergebnisse der Studie als Orientierungshilfe bei der Gestaltung ihrer Logistiksysteme und ihres Innovationsmanagements dienen. Die Studie analysiert anhand einer Online-Befragung den Umgang mit innovativen Logistiktechnologien bei Logistikdienstleistern und ihren Kunden aus Industrie und Handel. Die Top-Performer unter den Teilnehmern messen den einzelnen Technologien in der Regel eine höhere strategische Bedeutung bei als die übrigen Studienteilnehmer und verfolgen häufiger Wissensaufbau- und Investitionsstrategien. An diese Ergebnisse anknüpfend wurde ein technologieorientiertes Zukunftsbild der Kontraktlogistik entwickelt, das 16 konkrete Anwendungsszenarien von Technologien veranschaulicht. In einer Gruppen-Delphi-Untersuchung wurden diese Anwendungsszenarien mit zwölf Experten aus der Praxis diskutiert und ihre Eintrittswahrscheinlichkeit zu verschiedenen Zeitpunkten eingeschätzt. Bis 2015 halten die Experten nur bei drei Szenarien eine breite Durchsetzung für wahrscheinlich, der Großteil wird sich erst bis 2020 oder danach etablieren. Für das Innovationsmanagement bei Logistikdienstleistern wurde mit Hilfe einer Online-Befragung im ersten Schritt der Status quo wesentlicher Gestaltungsfelder untersucht. Anschließend wurden im Rahmen eines Workshops mit zwölf Praxisexperten spezifische Herausforderungen und konkrete Gestaltungsempfehlungen für ein erfolgreiches Innovationsmanagement bei Logistikdienstleistern abgeleitet. Das Innovationsmanagement sollte eine Kultur der Offenheit und des Wandels etablieren, wobei alle wesentlichen Anspruchsgruppen zu integrieren sind und gleichzeitig ein anforderungsgerechtes methodisches Fundament geschaffen werden muss., New technological developments are the course of innovations in logistics and paving the way for them at the same time. Moreover, technologies and innovations are important leverages for creating competitive advantages for logistics service providers. Against this backdrop, the focus of this study is twofold: future technologies in logistics and innovation management at logistics service providers. Contract logistics service providers take center stage of the investigation. However, the results are of particular interest for companies from industry and commerce as well. They support decision makers in designing their future logistics systems and give guidance for managing logistics innovation. By conducting an online survey, we asked managers of logistics service providers and logistics managers of industry and commerce companies about their knowledge and exposure to future technologies. Top performing companies in our sample show higher engagement and propensity to invest in new technologies. Based on the survey results, a picture of the contract logistics’ future was developed, integrating 16 relevant use cases of future technologies. These use cases were subject to a group Delphi with 12 logistics managers. By this means, these use cases were discussed and estimations for their breakthroughs in different time frames were elaborated. For only three use cases a breakthrough until 2015 was estimated as likely by the majority of the experts. The other scenarios are likely to take place in 2020 or later. The second part of the study begins with the status quo of innovation management at logistics service providers. For that purpose, again an online survey was applied. In a second step, a workshop with 12 logistics managers served to identify logistics service providers’ specific challenges and recommended actions for implementing an innovation management. The results show that an open culture linked with the willingness to change has to be established. Concurrently, all relevant groups have to be integrated and a solid foundation of appropriate methods should be created.
- Published
- 2013
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29. State-of-the-Art of RFID-Standardization:Players and Relationships
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Spiegel, Timo, Bensel, Philipp, Vogeler, Stefan, Straube, Frank, and Straube, Frank
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ddc:620 - Abstract
Nachdem im ersten Teil der Reihe „Aktuelle Situation der RFID-Standardisierung“ die Bedeutung der Standardisierung für die zukünftige Entwicklung der RFID-Technologie verdeutlicht wurde, sollen in diesem zweiten Teil die wichtigsten Akteure der RFID-Standardisierung vorgestellt werden. Die Verbindungen zwischen diesen Akteuren werden anhand einer Standardisierungslandkarte visualisiert.
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- 2007
30. State-of-the-Art of RFID-Standardization:Supply Chain Management
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Spiegel, Timo, Bensel, Philipp, Vogeler, Stefan, Straube, Frank, and Straube, Frank
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ddc:620 - Abstract
Der Beitrag gibt eine Übersicht über gängige Definitionen der mit der Standardisierung assoziierten Begriffe und schafft somit ein grundlegendes Verständnis. Des Weiteren wird der Standardisierungsprozess im Detail beschrieben. Schließlich werden verschiedene Schemata zur Kategorisierung von Standards vorgestellt und in eine auf die RFID-Standardisierung angepasste Systematik überführt.
- Published
- 2007
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