On the potential for a bottom active layer below coastal permafrost: the impact of seawater on permafrost degradation imaged by electrical resistivity tomography (Hornsund, SW Spitsbergen)

This paper presents the results of two-dimensional electrical resistivity tomography (ERT) of permafrost developed in coastal zone of Hornsund, SW Spitsbergen. The measurements were made using the Wenner-Schlumberger electrode array with an electrode spacing 5 m for overview and 1.5 or 1 m spacing for detailed imaging. Using the ERT inversion results, we studied the ‘sea influence’ on deeper parts of the frozen ground. During the investigations we tested hypotheses that the operation of seawater on shoreface may cause changes in the shape of the coastal permafrost base, and that the impact of seawater on more inland permafrost depends on the shape of the shoreline (differently in the embayment, and differently in a headland exposed to the open sea). Our study was inspired by previous ground temperature measurements conducted in several boreholes located in study area which captured the propagation of ground heat waves from the base of permafrost. Our resistivity models indicate a major differentiation in terms of resistivity of permafrost in the coastal zone. The resistivity measures obtained in deeper layers of ground were so low (< 100 Ω·m) that in the ‘warm permafrost’ conditions they exclude a possibility of freezing the coastal sediments and bedrock from the side of the sea. Low values continue further inland, going down under the surface layer of permafrost with higher resistivity. We interpret this situation as an influence of seawater's temperature and salinity on deeper parts of permafrost. Based on the measurements conducted within two years, we stated a change in the distribution of resistivity, both in the active layer, and in coastal front of permafrost in deeper parts of the ground. As observed in the inverse models, the geometric arrangement between the fields of extreme resistivity indicates the existence of a bottom active layer by the permafrost base, depending on thermal and chemical characteristics of seawater. The measurements conducted in the embayment, as well as on the headland exposed to the operation of storm waves, proved strong differences in the scale of the impact of seawater on permafrost

Kaliningrad Oblast 2016. The society, economy and army. OSW Report 12/2016

Moscow has been developing a new model of governance for Kaliningrad Oblast in 2016. The changes in the regional government (the governance of the oblast was entrusted to people sent from Moscow and had no links with the region) were part of it. These are a result of Russia’s depleting financial resources and austerity policy, the increasing militarisation of the Russian Federation and the important role the oblast plays in this policy, and the need to ensure a satisfactory result in the upcoming presidential election. Although there are at present no visible symptoms suggesting an intensification of protest sentiments, Moscow is taking preventive action to try to tighten its grip on local elites and residents. Kaliningrad Oblast remains an essential element of the Russian military strategy in the Baltic region. This is borne out by the deployment in the region of S-400 air defence systems, ships equipped with Kalibr missiles, and Bastion missile defence systems (which are nominally anti-ship weapons but are also adjusted to attacking ground targets). Furthermore, the deployment of Iskander missile systems has been launched which enables the creation of a so-called ‘Anti-Access/Area Denial’ (A2/AD) zone, extending the range of Russian weapons to the territories and airspace of the neighbouring NATO member states

Little Steps Towards Big Goals. Using Linked Data to Develop Next Generation Spatial Data Infrastructures (aka SDI 3.0)

Ponencias, comunicaciones y pósters presentados en el 17th AGILE Conference on Geographic Information Science "Connecting a Digital Europe through Location and Place", celebrado en la Universitat Jaume I del 3 al 6 de junio de 2014.Society is moving at an increasing pace toward the next stage of the information society through linked data. Among the relevant developments in geographic information science, linked data approaches offer potential for improving SDI functionality [12]. Linked data uses Semantic Web technologies and makes it possible to link at a very granular level data resources of the web for a multitude of purposes. While the technological implementation in many ways is still in a phase of adolescence, vast amounts of data, including geographic information (GI) have been prepared, for example by the UK Ordinance Survey [8] and other governmental and non-governmental bodies. The overwhelming focus has been on producing RDF formatted data for linked data applications--the foundation for applications. In this short paper, we provide an overview of potentials of linked open data for SDI 3.0 developments. Through two exemplary use cases we illustrate specifically some first steps towards a more web-oriented and distributed approach to creating SDI architectures. The cases demonstrate applications based on the LOD4WFS Adapter, which opens the way for multi-perspective GI applications, created on-demand from multiple GI data resources. These applications automate geometry-based selections of data using spatial queries with the use of RCC8 and OGC Simple Features topological functions. Future work in this area includes adding semantic operators to refine GI processing with multiple ontologies

Arctic rock coast responses under a changing climate

It has been widely reported that Arctic sea ice has decreased in both extent and thickness, coupled with steadily rising mean annual temperatures. These trends have been particularly severe along the rock coast of southern Svalbard. Concerns have been raised over the potential for higher energy storms and longer ice-free open water seasons to increase the exposure of Arctic coasts, and consequently the concentration of infrastructure critical to Arctic community survival, to enhanced rates of erosion. Here we present and apply innovative remote sensing, monitoring and process analyses to assess the impact of recent coastal climatic changes. High resolution analyses demonstrate that the small scale (<0.001 m3) changes that are rarely considered quantitatively exhibit geomorphic responses distinct from those of larger, more readily detected cliff failures. We monitor temperature depth profiles in both the shore platform and the cliff face to show rock sensitivity over time to both global and local influences. The results demonstrate the efficacy of thermal processes on Arctic rock cliffs relative to platforms, and may hold implications for understanding strandflat development rates. New three-dimensional thermography (thermal mapping) and process zone characterisation has been used to spatially assess the sensitivity of Arctic rock coast responses to contemporary processes on deglaciating coasts. Through the spatial and temporal analyses of key geomorphic behaviour zones and comparison over a range of sites, the complex and changing interplay between subaerial weathering and cryogenic and intertidal processes has been highlighted. These data challenge long standing assumptions over the future of Arctic rock coasts and identify new, focused lines of enquiry on the decline in cryogenic processes and understanding the sensitivity of Arctic rock coasts to climatic changes

3D PET image reconstruction based on Maximum Likelihood Estimation Method (MLEM) algorithm

Positron emission tomographs (PET) do not measure an image directly. Instead, they measure at the boundary of the field-of-view (FOV) of PET tomograph a sinogram that consists of measurements of the sums of all the counts along the lines connecting two detectors. As there is a multitude of detectors build-in typical PET tomograph structure, there are many possible detector pairs that pertain to the measurement. The problem is how to turn this measurement into an image (this is called imaging). Decisive improvement in PET image quality was reached with the introduction of iterative reconstruction techniques. This stage was reached already twenty years ago (with the advent of new powerful computing processors). However, three dimensional (3D) imaging remains still a challenge. The purpose of the image reconstruction algorithm is to process this imperfect count data for a large number (many millions) of lines-of-responce (LOR) and millions of detected photons to produce an image showing the distribution of the labeled molecules in space.Comment: 10 pages, 7 figure

Application of the compress sensing theory for improvement of the TOF resolution in a novel J-PET instrument

Nowadays, in positron emission tomography (PET) systems, a time of fl ight (TOF) information is used to improve the image reconstruction process. In TOF-PET, fast detectors are able to measure the difference in the arrival time of the two gamma rays, with the precision enabling to shorten signifi cantly a range along the line-of-response (LOR) where the annihilation occurred. In the new concept, called J-PET scanner, gamma rays are detected in plastic scintillators. In a single strip of J-PET system, time values are obtained by probing signals in the amplitude domain. Owing to compressive sensing (CS) theory, information about the shape and amplitude of the signals is recovered. In this paper, we demonstrate that based on the acquired signals parameters, a better signal normalization may be provided in order to improve the TOF resolution. The procedure was tested using large sample of data registered by a dedicated detection setup enabling sampling of signals with 50-ps intervals. Experimental setup provided irradiation of a chosen position in the plastic scintillator strip with annihilation gamma quanta

Plastic scintillators for positron emission tomography obtained by the bulk polymerization method

This paper describes three methods regarding the production of plastic scintillators. One method appears to be suitable for the manufacturing of plastic scintillator, revealing properties which fulfill the requirements of novel positron emission tomography scanners based on plastic scintillators. The key parameters of the manufacturing process are determined and discussed.Comment: 7 pages, 4 figure