ALBERT

Description: Profound societal transformations are needed to move society from unsustainability to greater sustainability under continually changing social and environmental conditions. A key challenge is to understand the influences on and the dynamics of collective behavior change toward sustainability. In this paper we describe our approach to (1) understanding how affective narrative expressions influence transitions to more sustainable collective behaviors and (2) how that understanding, as well as the potential for using narrative expressions in modeling of social movements, can become a basis for improving community responses to change in a rapidly changing world. Our focus is on narratives that express visions of desirable futures and narratives that reflect individual and social identities, on the cultures and contexts in which they are embedded, exchanged, and modified, and through which they influence the dynamics of social movements toward sustainability. Using an analytical categorization of narrative expressions of case studies in the Caribbean, Micronesia, and Africa, we describe insights derived from the narratives of vision and social identities in diverse communities. Finally, we suggest that narrative expressions may provide a basis for agent-based modeling to expand thinking about potential development pathways of social movements for sustainable futures.

Description: In this study we derive the stress tensor and its local variations throughout the Marmara region, Turkey. Based on a recently compiled 10-year earthquake catalogue, we directly invert first-motion polarity data and quantify confidence intervals for the principal stress orientations. We find a combined strike-slip and normal faulting stress field for the Marmara region generally reflecting the overall transtensional setting. However, the results clearly show moderate local variations of the stress field. The largest (σ1) and intermediate (σ2) principal stresses show an average regional trend of N125∘E and locally varying plunges. The least principal stress (σ3) is well resolved in its confidence interval and consistent throughout the region with an average trend of ∼ N35∘E and a subhorizontal plunge. The eastern Sea of Marmara shows local stress field orientations with pronounced strike-slip (northern part) and normal faulting (southern part) components. Along the central Marmara region, normal faulting tends to dominate, while a well resolved strike-slip stress regime is found in the western Sea of Marmara region. Regarding the faulting mechanism of an earthquake with magnitude up to 7.4 which is expected in this area in direct vicinity of the Istanbul metropolitan region, our results imply that neither strike-slip nor normal faulting kinematics can be excluded.

Description: Particulate material plays a major role in the transport of sparingly soluble nutrients such as P and Fe in natural surface waters. Microbes might gain access to these nutrients either indirectly through particulate dissolution or directly through microbial attack. As such, it seems reasonable to expect a link between the particulate material concentration and bacterial growth in natural surface waters. To explore this link, a series of microcosm growth experiments were performed in the presence of a typical freshwater cyanobacteria, Synechococcus sp., grown in dilute BG-11 culture media in the presence and absence of basaltic and continental riverine particulate material. Results demonstrate that riverine particulates can increase bacterial biomass by 1) triggering bacterial growth in otherwise unfavourable conditions, 2) increasing total maximum biomass concentration, and 3) inducing bacteria growth during the post-exponential phase. These effects are found to be enhanced by increasing particulate concentration. Results also indicate a positive feedback between the nutrient release from the particulates and growing bacteria, where dissolving particulates enhance bacterial growth, which further promotes particulate dissolution by altering fluid pH. Microscopic analysis showed direct physical contact between particulates and cyanobacteria, suggesting that bacteria attach directly on mineral surfaces to gain required nutrients. Furthermore, frequent bacteria clusters were observed associated with particulates, indicating an increasing aggregation of bacteria in the presence of particulate material, which may facilitate a higher burial efficiency of organic carbon.

Description: The ice-free areas of the South Shetland Islands are dominated by periglacial and glacial processes and landforms, closely associated with deposits of fluvial and coastal origin that are characteristic within the northern Antarctic Peninsula region. These areas are influenced by cold maritime climatic conditions and have experienced the greatest warming within the southern hemisphere over the past sixty years. As a result, freeze-thaw cycles are favoured implying dynamic processes in the active layer of the permafrost, which lead to the formation of different types of surface features. Studies have shown that these ice-free areas have often contained fragile ecosystems with a high biodiversity where many different plant and animal species are concentrated and an active hydrologic cycle during the Austral summer period. It is therefore important to monitor present-day active periglacial and glacial processes linked to recent global changes. Furthermore, determining the spatial distribution of diverse periglacial landforms will be key to detect the presence of permafrost. The objective of this work is to determine and monitor the spatial distribution of landforms of different origin, with special focus on those connected with periglacial processes and the presence of permafrost within ice-free areas. The studied area is located along the southern coast of Livingston Island between Hannah Point and Bernard Point using satellite-borne single and fully polarimetric Synthetic Aperture Radar (SAR) data and techniques. A fully polarimetric fine RADARSAT-2 image as Single Look Complex data was acquired through the Canadian Space Agency within the framework of the Science and Operational Applications Research Program (Project SOAR-5169) on the 29th of March 2014. Single polarimetric SENTINEL-1 images of 2017 and 2018 were obtained through the European Space Agency. Pre-processing of the SAR data includes radiometric correction, using a speckle noise filter, developed specifically within the team for both SAR single channel images and fully polarimetric images. A digital terrain model is used to carry out the terrain and geometric corrections. Polarimetric parameters are extracted from the RADARSAT-2 data and related to the different surface covers according to the backscattering characteristics received by the sensor within selected field sites. Furthermore, backscattering characteristics are also determined for the single polarimetric SENTINEL-1 data. Several field campaigns carried out during 2013, 2017 and 2018 provided reference for determining the different surface covers. A supervised classification is carried out using Random Forest (RF), a decision tree-based classifier using the different SAR data as well as DEM information. The detailed field observations are further used as reference for the classifier where the importance of each polarimetric parameter is determined in characterizing a particular surface cover. A final step is the validation of the mapping results obtained for the different ice-free areas using both field data and existing maps that have been compiled by the authors team. Initial results show that periglacial and glacial landforms such as patterned ground, stone fields, block glaciers, ice fronts, moraines as well as raised beach systems and abundant rock outcrops are well identified with the polarimetric RADARSAT-2 and SENTINEL-1 data. The elevation data is also of importance, as this nicely differentiates the areas above certain altitudes in which permafrost exist. Using RF, a variable ranking of the polarimetric parameters for individual terrain classes can be obtained. This is useful when trying to distinguish different classes that bear resemblance to each other such as patterned ground and stone fields. The final mapping is therefore based using the most relevant variables obtained from the different data. The distribution of surface covers obtained with this approach can then be used in time series analysis for future monitoring of changes in ice-free areas of Livingston Island. This would be a novel approach to monitor the active periglacial and glacial processes.