ALBERT

Description: The sedimentation regime off Northwest Africa is shaped by: (1) structur~al factors. which result in generallv low relief on land. shelf widths between 40 and more than 120 km. and av-erage sfope inclinations between 10 30' and 30; (2) land climates. which contral the delivery of terrigenous particles to the margin: (3) water movements including boundary currents and upwelling; and (4) the post- Pleistocene sea level rise. This chapter combines published and new results arising from research into the sedimentation processes off Northwest Africa. and emphasizes particularly the activities of the Kiel marine geological group during the past few years. Reviews of cruise activities and results were given in Closs et al. (1969) (Meteor cruise 8. 1967. off Morocco) . Seibold (1972) (Meteor cmise 25 . 1971. off Sahara to Central Senegal). Seibold and Hinz (1976) (Meteor cmise 39,1975 . and Valdivia cruise 10. 1975, from Morocco to South Senegal), and Waiden et al. (1974) (Meteor cmise 30, 1973, off Sierra Leone). Some of these cmises were used for pre- or post-site surveys for the Deep-Sea Drilling Project, or to add undisturbed Quaternary cores to the Glomar Challenger cores (leg 41, ] 975; Lancelot, et al .• 1978); leg 47 A, Arthur er al .• 1979; Lutze et al., 1979). We have concentrated our geological investigations on a number of standard profiles from the shelf to the upper continental rise as given in Figure 1. The manuscript was finished May 1979.

Description: An ensemble-based data assimilation framework for a coupled ocean–atmosphere model is applied to investigate the influence of assimilating different types of ocean observations on the ocean and atmosphere simulation. The data assimilation is performed with the parallel data assimilation framework (PDAF) for the climate model AWI-CM. Observations of the ocean, namely satellite sea-surface temperature (SST) and temperature and salinity profiles, are assimilated into the ocean component. The atmospheric state is only influenced by the model dynamics. Different assimilation scenarios were carried out with different combinations of observations to investigate to what extent the assimilation into the coupled model leads to a better estimation of the state of the ocean as well as the atmosphere. The influence of the data assimilation is assessed by comparing the ocean prediction with dependent and independent ocean observations. For the atmosphere, the assimilation result is compared with the ERA-Interim atmospheric reanalysis data. The ocean temperature and salinity are improved by all the assimilation scenarios in the coupled system. The assimilation leads to a response of the atmosphere throughout the troposphere and impacts the global atmospheric circulation. Globally the temperature and wind speed are improved in the atmosphere on average.

Description: To evaluate the present sea-ice changes in a longer-term perspective the knowledge of sea-ice variability on pre-industrial and geological time scales is essential. For the interpretation of proxy reconstructions it is necessary to understand the recent signals of different sea-ice proxies from various regions. We present 260 new sediment surface samples collected in the (sub-) Arctic Oceans that were analysed for specific sea-ice (IP25) and open-water phytoplankton biomarkers (brassicasterol, dinosterol, HBI III). This new biomarker dataset was combined with 615 previously published biomarker surface samples into a pan-Arctic database. The resulting pan-Arctic biomarker and sea-ice index (PIP25) database shows a spatial distribution correlating well with the diverse modern sea-ice concentrations. We find correlations of PBIP25, PDIP25 and PIIIIP25 with spring and autumn concentrations. Similar correlations with modern sea-ice concentrations are observed in Baffin Bay. However, the correlations of the PIP25 indices with modern sea-ice concentrations differ in Fram Strait from those of the (sub-) Arctic dataset, which is likely caused by region-specific differences in sea-ice variability, nutrient availability and other environmental conditions. The extended (sea-ice) biomarker database strengthens the validity of biomarker sea-ice reconstructions in different Arctic regions and shows how different sea-ice proxies combined may resolve specific seasonal sea-ice signals.

Description: 〈jats:title〉Abstract〈/jats:title〉〈jats:p〉 〈jats:list〉 〈jats:list-item〉〈jats:p〉Social–ecological systems (SES) exhibit complex cause‐and‐effect relationships. Capturing, interpreting, and responding to signals that indicate changes in ecosystems is key for sustainable management in SES. Breaks in this signal–response chain, when feedbacks are missing, will allow change to continue until a point when abrupt ecological surprises may occur.〈/jats:p〉〈/jats:list-item〉 〈jats:list-item〉〈jats:p〉In these situations, societies and local ecosystems can often become uncoupled. In this paper, we demonstrate how the red loop–green loop (RL–GL) concept can be used to uncover missing feedbacks and to better understand past social–ecological dynamics. Reinstating these feedbacks in order to recouple the SES may ultimately create more sustainable systems on local scales.〈/jats:p〉〈/jats:list-item〉 〈jats:list-item〉〈jats:p〉The RL–GL concept can uncover missing feedbacks through the characterization of SES dynamics along a spectrum of human resource dependence. Drawing on diverse qualitative and quantitative data sources, we classify SES dynamics throughout the history of Jamaican coral reefs along the RL–GL spectrum. We uncover missing feedbacks in red‐loop and red‐trap scenarios from around the year 600 until now. The Jamaican coral reef SES dynamics have moved between all four dynamic states described in the RL–GL concept: green loop, green trap, red loop and red trap.〈/jats:p〉〈/jats:list-item〉 〈jats:list-item〉〈jats:p〉We then propose mechanisms to guide the current unsustainable red traps back to more sustainable green loops, involving mechanisms of seafood trade and ecological monitoring. By gradually moving away from seafood exports, Jamaica may be able to return to green‐loop dynamics between the local society and their locally sourced seafood. We discuss the potential benefits and drawbacks of this proposed intervention and give indications of why an export ban may insure against future missing feedbacks and could prolong the sustainability of the Jamaican coral reef ecosystem.〈/jats:p〉〈/jats:list-item〉 〈jats:list-item〉〈jats:p〉Our approach demonstrates how the RL–GL approach can uncover missing feedbacks in a coral reef SES, a way the concept has not been used before. We advocate for how the RL–GL concept in a feedback setting can be used to synthesize various types of data and to gain an understanding of past, present and future sustainability that can be applied in diverse social–ecological settings.〈/jats:p〉〈/jats:list-item〉 〈/jats:list〉 〈/jats:p〉〈jats:p〉A free 〈jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://onlinelibrary.wiley.com/doi/10.1002/pan3.10092/suppinfo"〉Plain Language Summary〈/jats:ext-link〉 can be found within the Supporting Information of this article.〈/jats:p〉

Description: 〈jats:title〉Abstract〈/jats:title〉〈jats:p〉 〈jats:list〉 〈jats:list-item〉〈jats:p〉Herbivory is a key process on coral reefs, which, through grazing of algae, can help sustain coral‐dominated states on frequently disturbed reefs and reverse macroalgal regime shifts on degraded ones.〈/jats:p〉〈/jats:list-item〉 〈jats:list-item〉〈jats:p〉Our understanding of herbivory on reefs is largely founded on feeding observations at small spatial scales, yet the biomass and structure of herbivore populations is more closely linked to processes which can be highly variable across large areas, such as benthic habitat turnover and fishing pressure. Though our understanding of spatiotemporal variation in grazer biomass is well developed, equivalent macroscale approaches to understanding bottom‐up and top‐down controls on herbivory are lacking.〈/jats:p〉〈/jats:list-item〉 〈jats:list-item〉〈jats:p〉Here, we integrate underwater survey data of fish abundances from four Indo‐Pacific island regions with herbivore feeding observations to estimate grazing rates for two herbivore functions, cropping (which controls turf algae) and scraping (which promotes coral settlement by clearing benthic substrate), for 72 coral reefs. By including a range of reef states, from coral to algal dominance and heavily fished to remote wilderness areas, we evaluate the influences of benthic habitat and fishing on the grazing rates of fish assemblages.〈/jats:p〉〈/jats:list-item〉 〈jats:list-item〉〈jats:p〉Cropping rates were primarily influenced by benthic condition, with cropping maximized on structurally complex reefs with high substratum availability and low macroalgal cover. Fishing was the primary driver of scraping function, with scraping rates depleted at most reefs relative to remote, unfished reefs, though scraping did increase with substratum availability and structural complexity.〈/jats:p〉〈/jats:list-item〉 〈jats:list-item〉〈jats:p〉Ultimately, benthic and fishing conditions influenced herbivore functioning through their effect on grazer biomass, which was tightly correlated to grazing rates. For a given level of biomass, we show that grazing rates are higher on reefs dominated by small‐bodied fishes, suggesting that grazing pressure is greatest when grazer size structure is truncated.〈/jats:p〉〈/jats:list-item〉 〈jats:list-item〉〈jats:p〉Stressors which cause coral declines and clear substrate for turf algae will likely stimulate increases in cropping rates, in both fished and protected areas. In contrast, scraping functions are already impaired at reefs inhabited by people, particularly where structural complexity has collapsed, indicating that restoration of these key processes will require scraper biomass to be rebuilt towards wilderness levels.〈/jats:p〉〈/jats:list-item〉 〈/jats:list〉 〈/jats:p〉〈jats:p〉A free 〈jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.13457/suppinfo"〉Plain Language Summary〈/jats:ext-link〉 can be found within the Supporting Information of this article.〈/jats:p〉

Description: The zooplankter Calanus finmarchicus is a member of the so-called “Calanus Complex”, a group of copepods that constitutes a key element of the Arctic polar marine ecosystem, providing a crucial link between primary production and higher trophic levels. Climate change induces the shift of C. finmarchicus to higher latitudes with currently unknown impacts on its endogenous timing. Here we generated a daily transcriptome of C. finmarchicus at two high Arctic stations, during the more extreme time of Midnight Sun, the summer solstice. While the southern station (74.5 °N) was sea ice-free, the northern one (82.5 °N) was sea ice-covered. The mRNAs of the 42 samples have been sequenced with an average of 126 ± 5 million reads (mean ± SE) per sample, and aligned to the reference transcriptome. We detail the quality assessment of the datasets and the complete annotation procedure, providing the possibility to investigate daily gene expression of this ecologically important species at high Arctic latitudes, and to compare gene expression according to latitude and sea ice-coverage.

Description: Blue economy initiatives have emerged along marine and coastal areas, seeking to bring the green economy into a ‘blue world’. Often defined as a global policy agenda, blue economy discourses and practices aim to generate ‘blue growth’ by linking poverty reduction, social equality, and marine conservation. While global and national policies have spent decades addressing coastal resource management, broader blue economy discourses and practices seem, on the surface, to promote economic growth strategies for marine conservation. Increasingly, new market-oriented programs and projects aim to tap the financial value of the ocean’s ‘blue capital’, ostensibly fostering income generation and sustainable solutions for conservation finance. Drawing on critical discourse analysis and key-informant interviews across scales, we examine the meanings and practices of the blue economy in Southeast Asia and in the Philippines. As an archipelagic nation, millions of coastal dwellers in the Philippines depend on oceans as a major source of livelihood, food security, and well-being. We examine how multilateral institutions, bilateral organisations, state agencies, civil society organisations, and other key actors represent and enact the blue economy discursively and in practice. We find that oceans are being imagined as an open frontier that must be managed and utilised for both conservation and economic purposes. New territorialisation processes are creating new borders and management structures that often bypass social and environmental safeguards, posing a major threat to coastal dwellers. We conclude that by foregrounding economic development and coastal management, more socially just and environmentally sustainable governance approaches are neglected.

Description: 3D earthquake locations, focal mechanisms and stress tensor distribution in a 16- month interval covering the 2018 Mt. Etna flank eruption, enabled us to investigate the relationship between magma intrusion and structural response of the volcano and shed light on the dynamic processes affecting the instability of Mt. Etna. The magma intrusion likely caused tension in the flanks of the volcano, leading to significant ground deformation and redistribution of stress on the neighbouring faults at the edge of Mt. Etna's unstable sector, encouraging the ESE sliding of the eastern flank of the volcano. Accordingly, FPSs of the post-eruptive events show strike slip faulting mechanisms, under a stress regime characterized by a maximum compressive σ1, NE-SW oriented. In this perspective, any flank eruption could temporarily enhance the sliding process of both the southern and eastern flanks of the volcano.

Description: Published

Description: 334-344

Description: 5V. Processi eruttivi e post-eruttivi

Description: JCR Journal