Assembly and concept of a web-based GIS within the paleolimnological project CONTINENT (Lake Baikal,Russia)

Web-based Geographical Information Systems (GIS) are excellent tools within interdisciplinary and multi-national geoscience projects to exchange and visualize project data. The web-based GIS presented in this paper was designed for the paleolimnological project ‘High-resolution CONTINENTal paleoclimate record in Lake Baikal’ (CONTINENT) (Lake Baikal, Siberia, Russia) to allow the interactive handling of spatial data. The GIS database combines project data (core positions, sample positions, thematic maps) with auxiliary spatial data sets that were downloaded from freely available data sources on the world wide web. The reliability of the external data was evaluated and suitable new spatial datasets were processed according to the scientific questions of the project. GIS analysis of the data was used to assist studies on sediment provenance in Lake Baikal, or to help answer questions such as whether the visualization of present-day vegetation distribution and pollen distribution supports the conclusions derived from palynological analyses. The refined geodata are returned back to the scientific community by using online data publication portals. Data were made citeable by assigning persistent identifiers (DOI) and were published through the German National Library for Science and Technology (TIB Hannover, Hannover, Germany).     

Slope stability modelling with SINMAP in a settlement area of the Swabian Alb

During the last decades, damages to houses caused by landslides have been consistently occurring in a residential area in Öschingen/Germany. The residential area is located in ductile Callovian clays (Jurassic). Furthermore, in the back slope of the research area, a large Pleistocene slide mass negatively influences the slope stability. Through an integrative approach, the maximum data available for the study area was compiled in order to create a susceptibility map for landslide hazard. Detailed geomorphological field survey provided a valuable base for the assessment of slope stability using Stability Index Mapping (SINMAP). In the framework of long-term studies, consolidated results concerning mass movements and climatic-driven Pleistocene slope evolution, as well as recent slope dynamics, could be gained. These outcomes are compared to the results provided by slope stability modelling with SINMAP. The calculations outline some parameters responsible for higher risks. In general, the interaction of topography, water balances and substrate at the Schönberger Kapf can be designated to cause instability in wide areas. Hydrological parameters are essential for destabilisation of slope and they cause at least temporally destabilisation along channel structures, which presumably are influenced by seasonally increased spring discharge and a reduction in the underground shear strength. The exceptional dimension of the rotational block in connection with the specific slope hydrologic conditions and the intensive anthropogenic impact in the rear slope of the building area Auchtert in Öschingen has to be termed very problematic on the basis of the studies carried out.     

A 1,000-year ice core record of interannual to multidecadal variations in atmospheric circulation over the North Atlantic

Interannual to multidecadal modes in ocean/atmosphere dynamics in the North Atlantic region have been identified using sea salt aerosol proxy records from northern Greenland ice cores over the last 1,000 years. Sea salt concentrations show a consistent relationship with anomalies in the meridional pressure gradient over the North Atlantic region over all considered time scales. These pressure anomalies are connected to shifts in storm tracks, leading to lower pressure and higher storm activity, hence, higher sea salt export over the Greenland ice sheet. Two modes of long-term variability with a period of 10.4 years and 62 years could be identified. The latter is connected to long-term changes in sea surface temperature (SST) as documented by a high correlation of North Atlantic SST with our sea salt record over the last 150 years. Long-term reconstruction of these modes shows that the 10.4-year cycle has been a phenomenon persistent over the last millennium while the 62-year cycle has been mainly active after 1700. Accordingly, the longer-term persistence of this multidecadal variability in sea salt points also to significant variations in SST over the last 300 years.     

Geochemistry and lithofacies of Permo-Carboniferous carbonaceous rocks from the southwestern edge of the Bohemian Massif (Germany). A contribution to facies analysis of continental anoxic environments

The Permo-Carboniferous Schmidgaden, Weiden, Erbendorf and Stockheim basins from southern Germany host discontinuous seams of high ash coal and carbargillites which were mined for hard coal, explored for uranium and only recently have proved their source rock potential for gaseous and fluid hydrocarbons. Alteration and facies of these carbonaceous beds were geologically and chemically investigated. During silicification which is exclusively confined to the carbonaceous interbeds of pyroclastic depositions, element depletion prograded except for Zn, Pb, U. The anoxic environments under consideration may be subdivided into fluvial/swamp (Upper Westphalian beds from Schmidgaden, Weiden, Erbendorf and Stockheim) and lacustrine depositions (Upper Stephanian and Upper Autunian carbargillites from Erbendorf, Weiden-Bechtsrieth). SiO₂, MgO, CaO, Mo and Zr have proved to be most suitable for recognition of these environments, whereas, U, K₂O and notably Cu/Zn are less appropriate. In the ternary plots displaying the organic chemistry of extracts of these carbonaceous beds fluvial swamps have low and lacustrine beds high contents of saturated hydrocarbons. All samples show a pronounced OEP (=odd even predominance) of n-alkanes which partly are environment-controlled (terrestrial origin), partly maturity-controlled. The high iso- and cyclo-alkanes of Schmidgaden and bimodal n-alkyl distribution point to a contribution of algal material. Finally four basin types bearing carbonaceous rocks are discussed with respect to their economic potential and compared with basins elsewhere (Cerilly, Lodève, St. Hippolyte, Uinta): type I: intramontane fault-bounded basin (swamp), type II: volcanic-depression with steep relief (swamps), type III: halfgraben (lake), type IV: volcanic-depression with smooth relief (lake). Types I and II are of interest for hard coal, organic-hosted U-deposits and mainly gasprone; types III and IV, however, show good source-rock potential for crude oil.     

Deforestation and fragmentation of seasonal tropical forests in the southern Yucatán,Mexico (1990–2006)

The southern Yucatán (SY) has been recognized as a hotspot of biodiversity with great risk of deforestation. Land change analysis, based on classified Landsat TM and ETM?+?satellite imagery (1990, 2000 and 2006), was used to estimate the annual deforestation rates of 141 land management units of the SY, and spatial patterns of forest fragmentation around and within the Calakmul Biosphere Reserve (CBR), which comprises approximately one-third of the region. Results indicate a decrease in annual deforestation rates over 1990–2006, from 0.15% year^?1 to 0.06% year^?1, but with significant sub-regional variations in the quantity and rate of forest loss. Despite a decline in deforestation during this period, there was considerable fragmentation both inside and outside the CBR. While population pressures and the expansion of pasture have caused deforestation across the region, agricultural intensification, diversified income strategies and reserve conservation may have contributed to reduced forest loss during the study period.     

Variability and propagation of Labrador Sea Water in the southern subpolar North Atlantic

The variability of two modes of Labrador Sea Water (LSW) (upper and deep Labrador Sea Water) and their respective spreading in the interior North Atlantic Ocean are investigated by means of repeated ship surveys carried out along the zonal WOCE line A2/AR19 located at 43–48°N (1993–2007) and along the GOOS line at about 48–51°N (1997–2002). Hydrographic section data are complemented by temperature, salinity, and velocity time series recorded by two moorings. They have been deployed at the western flank of the Mid-Atlantic Ridge (MAR) in the Newfoundland Basin during 1996–2004. The analysis of hydrographic anomalies at various longitudes points to a gradual eastward propagation of LSW-related signals, which happens on time scales of 3–6 years from the formation region towards the MAR. Interactions of the North Atlantic Current (NAC) with the Deep Western Boundary Current (DWBC) close to Flemish Cap point to the NAC being the main distributor of the different types of LSW into the interior of the Newfoundland Basin. Comparisons between the ship data and the mooring records revealed that the mooring sites are located in a region affected by highly variable flow. The mooring time series demonstrate an elevated level of variability with eddy activity and variability associated with the NAC considerably influencing the LSW signals in this region. Hydrographic data taken from Argo profiles from the vicinity of the mooring sites turned out to mimic quite well the temporal evolution captured by the moorings. There is some indication of occasional southward flow in the LSW layer near the MAR. If this can be considered as a hint to an interior LSW-route, it is at least of minor importance in comparison to the DWBC. It acts as an important supplier for the interior North Atlantic, distributing older and recently formed LSW modes southward along the MAR.     

Stable carbon isotopic ratios of CH4-CO2-bearing fluid inclusions in fracture-fill mineralization from the Lower Saxony Basin (Germany) - A tool for tracing gas sources and maturity

The stable carbon isotopic ratios (δ¹³C) of methane (CH₄) and carbon dioxide (CO₂) of gas-rich fluid inclusions hosted in fracture-fill mineralization from the southern part of the Lower Saxony Basin, Germany have been measured online using a crushing device interfaced to an isotopic ratio mass spectrometer (IRMS). The data reveal that CH₄ trapped in inclusions seems to be derived from different source rocks with different organic matter types. The δ¹³C values of CH₄ in inclusions in quartz hosted by Carboniferous rocks range between −25 and −19‰, suggesting high-maturity coals as the source of methane. Methane in fluid inclusions in minerals hosted by Mesozoic strata has more negative carbon isotope ratios (−45 to −31‰) and appears to represent primary cracking products from type II kerogens, i.e., marine shales. There is a positive correlation between increasing homogenization temperatures of aqueous fluid inclusions and less negative δ¹³C(CH₄) values of in co-genetic gas inclusions probably indicating different mtaturity of the potential source rocks at the time the fluids were released. The CO₂ isotopic composition of CH₄-CO₂-bearing inclusions shows slight negative or even positive δ¹³C values indicating an inorganic source (e.g., water-rock interaction and dissolution of detrital, marine calcite) for CO₂ in inclusions. We conclude that the δ¹³C isotopic ratios of CH₄-CO₂-bearing fluid inclusions can be used to trace migration pathways, sources of gases, and alteration processes. Furthermore, the δ¹³C values of methane can be used to estimate the maturity of the rocks from which it was sourced. Results presented here are further supported by organic geochemical analysis of surface bitumens which coexist with the gas inclusion-rich fracture-fill mineralization and confirm the isotopic interpretations with respect to fluid source, type and maturity.     

Race/Ethnicity in Visual Imagery of Dutch Nature Conservation Organizations

Nature conservation organizations in various Western countries, including the Netherlands, have noted that racial/ethnic minorities compared to Whites are “underparticipating” in recreation in natural areas and in nature conservation practices. Previous research trying to explain (under-)participation by racial/ethnic minorities in outdoor recreation and nature conservation mainly focused on characteristics of racial/ethnic groups. This study argues that nature conservation organizations themselves—although in all likelihood unintentionally—may play a role in participation of racial/ethnic minorities as well, through their promotional material. A content analysis of 22,974 pictures in magazines and on websites of four large Dutch nature conservation organizations shows that only 3.8% of the depicted people were non-White. Our results indicate that visual imagery of nature conservation organizations, at least in the Netherlands, (re)produces an image of outdoor recreation and nature conservation as being activities almost exclusively performed by Whites.     

Urban Community Garden Agrodiversity and Cultural Identity in Philadelphia,Pennsylvania, U.S.

Considerable research has examined the social, cultural, economic, and community benefits of urban gardening. Few studies, however, have empirically assessed factors that influence urban community garden agrodiversity or its relationship to these dimensions of gardening. We conducted an interdisciplinary study of agrodiversity and cultural identity, based certain markers of identity, including how people see themselves with respect to race, ethnicity, or place of origin, in community gardens in Philadelphia, Pennsylvania. We conducted fifty‐six semistructured interviews with gardeners with different cultural identities in eight community gardens on their motivations for urban community gardening during 2014. We conducted plant inventories of the corresponding garden plots and found 104 cultivated edible and ornamental species and 28 varieties representing 34 families. We find that although gardens with culturally diverse gardeners did not have higher species richness, the cultural identity of the gardeners influenced species selection and reason for gardening. Further, the structure, design and species composition of garden plots reflected the identities of garden members. These finding have implications for the recent institutionalization of urban agriculture into city land policies in Philadelphia and other cities in North America.     

Very extreme seasonal precipitation in the NARCCAP ensemble: model performance and projections

Seasonal extreme daily precipitation is analyzed in the ensemble of NARCAPP regional climate models. Significant variation in these models’ abilities to reproduce observed precipitation extremes over the contiguous United States is found. Model performance metrics are introduced to characterize overall biases, seasonality, spatial extent and the shape of the precipitation distribution. Comparison of the models to gridded observations that include an elevation correction is found to be better than to gridded observations without this correction. A complicated model weighting scheme based on model performance in simulating observations is found to cause significant improvements in ensemble mean skill only if some of the models are poorly performing outliers. The effect of lateral boundary conditions are explored by comparing the integrations driven by reanalysis to those driven by global climate models. Projected mid-century future changes in seasonal precipitation means and extremes are presented and discussions of the sources of uncertainty and the mechanisms causing these changes are presented.