The importance of symbols in the region formation process

The aim in the article is to conceptualize the general foundations of research on the importance of regional symbolism in the process of region and regional identity formation. The article is founded on a critical analysis of works pertaining not only to the field of the new regional geography, but also to the field of regional marketing and/or branding, sociology, and semiology. The authors focus on meanings attributed to symbols and symbolism in literature, and observe which elements are viewed as regional symbols and how these symbols contribute to the process of regional development and institutionalization, especially in the formation of its symbolic shape. They examine the thematic and theoretical grounds, looking at identity, regional identity, and regional institutionalization. Next, regional symbols are defined and classified according to their types and forms, and their importance in the process of regional formation and institutionalization is discussed. The results show that symbols of any type can play an important role in a region’s marketing, and become the key image associated with a region. The authors conclude that regional symbols are a significant feature of the formation of a region and its identity, both outwardly (the external image of a region) and inwardly (concerning the inhabitants’ relationships with their region).     

Interpretation of shallow refraction seismic data by reflection/refraction tomography

A new algorithm for tomographic inversion of traveltimes of reflected and refracted seismic waves is developed. The inversion gives interface configurations and velocity distributions in layers. The important features of the algorithm are: (a) the inclusion of shot time delays in the list of unknown parameters; (b) the regularization is applied in such a way that the most probable model is characterized by the similarity of neighbouring interfaces. As the problem under consideration is non-linear, several iterations are necessary in order to obtain the final model. In the case of a very inexact initial model, a 'layer-by-layer' inversion strategy is recommended as a first inversion step. The inversion program is supplied with a user interface, thanks to which one can: (a) pick interactively and identify seismic traveltimes; (b) build and edit depth/velocity models; and (c) display calculated traveltime curves and compare them with picked traveltimes as well as with the original seismic sections. The efficiency of the inversion software developed is illustrated by a numerical example and a field example in which shallow seismic data are considered. Application to wide-aperture reflection/refraction profiling (WARRP) data is also possible.     

Ground motion simulations for seismic stations in southern and eastern Romania and seismic hazard assessment

This research focuses on the evaluation of soil conditions for seismic stations in southern and eastern Romania, their influence on stochastic finite-fault simulations, and the impact of using them on the seismic hazard assessment. First, the horizontal-to-vertical spectral ratios (HVSR) are evaluated using ground motions recorded in 32 seismic stations during small magnitude (M _W  ≤ 6.0) Vrancea seismic events. Most of the seismic stations situated in the southern part of Romania exhibit multiple HVSR peaks over a broad period range. However, only the seismic stations in the eastern-most part of Romania have clear short-period predominant periods. Subsequently, stochastic finite-fault simulations are performed in order to evaluate the influence of the soil conditions on the ground motion amplitudes. The analyses show that the earthquake magnitude has a larger influence on the computed ground motion amplitudes for the short- and medium-period range, while the longer-period spectral ordinates tend to be influenced more by the soil conditions. Next, the impact of the previously evaluated soil conditions on the seismic hazard results for Romania is also investigated. The results reveal a significant impact of the soil conditions on the seismic hazard levels, especially for the sites characterized by long-period amplifications (sites situated mostly in southern Romania), and a less significant influence in the case of sites which have clear short predominant periods.     

Evaluation of the seismic hazard for 20 cities in Romania using Monte Carlo based simulations

This work focuses on the evaluation of the seismic hazard for Romania using earthquake catalogues generated by a Monte Carlo approach. The seismicity of Romania can be attributed to the Vrancea intermediate-depth seismic source and to 13 other crustal seismic sources. The recurrence times of large magnitude seismic events (both crustal and subcrustal), as well as the moment release rates are computed using simulated earthquake catalogues. The results show that the largest contribution to the overall moment release for the crustal seismic sources is from the seismic regions in Bulgaria, while the seismic regions in Romania contribute less than 5% of the overall moment release. In addition, the computations show that the moment release rate for the Vrancea subcrustal seismic source is about ten times larger than that of all the crustal seismic sources. Finally, the Monte Carlo approach is used to evaluate the seismic hazard for 20 cities in Romania with populations larger than 100,000 inhabitants. The results show some differences between the seismic hazard values obtained through Monte-Carlo simulation and those in the Romanian seismic design code P100-1/2013, notably for cities situated in the western part of Romania that are influenced by local crustal seismic sources.     

Geomechanics of hazardous landslides

A catalogue of possible landslide initial failure mechanisms, taking into account the geological setting and the geometry of the slope, the joint structure, the habitus of the rock blocks, as well as the mechanical behaviour of the rocks and of the rock mass （deformation and strength parameters）, is presented. Its aim is to give geologists as well as engineers the opportunity to compare phenomena in the field and phenomena belonging to particular mechanisms and to find the mechanism occurring. The presented catalogue of initial landslide mechanisms only comprises the mechanisms having a clearly defined mechanical model that can be divided into empirical relations and into mechanical models, as well as an overview of run out models, which can be divided into empirical relations and into mechanical models.     

极地冰钻关键技术研究进展

极地冰钻技术是获取冰芯,研究冰盖-冰架-海洋相互作用,以及获取极地冰下基岩与冰下水环境样品,开展冰下环境探测的重要手段。目前极地冰钻技术的难点与前沿主要包括深冰芯钻探、冰架热水钻、冰下基岩钻和冰下水环境采样与观测技术。本文针对以上4个极地冰钻关键技术,对国内外相关技术的研究进展与项目开展情况进行了总结与梳理。综合来看,虽然我国开展极地钻探技术研究起步较晚,但随着我国极地战略不断推进,我国的极地冰钻关键技术与装备的研究正持续向着赶超极地钻探强国方向迈进,这必将为我国的极地科学研究提供强有力的技术支撑。     

Gravimetric monitoring of the first field‐wide steam injection in a fractured carbonate field in Oman – a feasibility study

Gas‐Oil Gravity Drainage is to be enhanced by steam injection in a highly fractured, low permeability carbonate field in Oman. Following a successful pilot, field‐wide steam injection is being implemented, first of this type in the world. A dedicated monitoring program has been designed to track changes in the reservoir. Various observations are to be acquired, including, surface deformation, temperature measurements, microseismic, well logs, pressure and saturation measurements to monitor the reservoir. Because significant changes in the reservoir density are expected, time‐lapse gravimetry is also being considered. In this paper we investigate the feasibility of gravimetric monitoring of the thermally enhanced gravity drainage process at the carbonate field in Oman. For this purpose, forward gravity modelling is performed. Based on field groundwater measurements, the estimates of the hydrological signal are considered and it is investigated under what conditions the groundwater influences can be minimized. Using regularized inversion of synthetic gravity data, we analyse the achievable accuracy of heat‐front position estimates. In case of large groundwater variations at the field, the gravity observations can be significantly affected and, consequently, the accuracy of heat‐front monitoring can be deteriorated. We show that, by applying gravity corrections based on local observations of groundwater, the hydrological influences can to a large extent be reduced and the accuracy of estimates can be improved. We conclude that gravimetric monitoring of the heat‐front evolution has a great potential.