An attempt to define a “neotectonic period” for central and northern Europe

The neotectonic period is the youngest period of tectonic evolution and extends up to the present. The beginning of the neotectonic period during the Cenozoic may be regarded as having begun when characteristic changes in the tectonic evolution of a region of interest have occurred for the last time. Changes in the different tectonic facets, which characterize the evolution of a region, need not be simultaneous, and hence the times of the last change may differ between facets. This leads to the definition of a transitional time interval wherein elements of both the palaeotectonic and neotectonic period are present. The length of this transitional time interval depends on the regional geological evolution. Where a broad transitional time interval exists, the beginning of the neotectonic period may be defined by the earliest time marker by when most of the characteristic changes of the tectonic evolution of the region had occurred.In defining the neotectonic period in central and northern Europe, data on the evolution of the northern Mid-Atlantic ridge and the northern Mediterranean convergence zone, inversion tectonics in northern and central Europe, rifting, regional subsidence and uplift, and the tectonic stress field as well as the evolution of the calcalkaline and alkaline volcanism in central Europe have been taken into account. The chronological evolution of these characteristics for the Cenozoic have been analysed with a view to identifying the advent of the neotectonic period. The transition from the end of the palaeotectonic period to the beginning of the neotectonic period extends from the middle early Miocene to the Miocene-Pliocene boundary. The earliest time by when most of the characteristic changes in the tectonic evolution of northern and central Europe had occurred is the early late Miocene. Thus, the neotectonic period can be considered to have begun at approximately 10 Ma before present.     

An integrated 1D–2D hydraulic modelling approach to assess the sensitivity of a coastal region to compound flooding hazard under climate change

Coastal regions are dynamic areas that often lie at the junction of different natural hazards. Extreme events such as storm surges and high precipitation are significant sources of concern for flood management. As climatic changes and sea-level rise put further pressure on these vulnerable systems, there is a need for a better understanding of the implications of compounding hazards. Recent computational advances in hydraulic modelling offer new opportunities to support decision-making and adaptation. Our research makes use of recently released features in the HEC-RAS version 5.0 software to develop an integrated 1D–2D hydrodynamic model. Using extreme value analysis with the Peaks-Over-Threshold method to define extreme scenarios, the model was applied to the eastern coast of the UK. The sensitivity of the protected wetland known as the Broads to a combination of fluvial, tidal and coastal sources of flooding was assessed, accounting for different rates of twenty-first century sea-level rise up to the year 2100. The 1D–2D approach led to a more detailed representation of inundation in coastal urban areas, while allowing for interactions with more fluvially dominated inland areas to be captured. While flooding was primarily driven by increased sea levels, combined events exacerbated flooded area by 5–40% and average depth by 10–32%, affecting different locations depending on the scenario. The results emphasise the importance of catchment-scale strategies that account for potentially interacting sources of flooding.

     

Groundwater for urban water supplies in northern China – An overview

 Groundwater plays an important role for urban and industrial water supply in northern China. More than 1000 groundwater wellfields have been explored and installed. Groundwater provides about half the total quantity of the urban water supply. Complete regulations and methods for the exploration of groundwater have been established in the P.R. China. Substantial over-exploitation of groundwater has created environmental problems in some cities. Some safeguarding measures for groundwater-resource protection have been undertaken. Received, August 1997 · Revised, February 1998 · Accepted, April 1998     

“Internet+” approach to mapping exposure and seismic vulnerability of buildings in a context of rapid socioeconomic growth: a case study in Tangshan,China

This paper presents the development of an “Internet+” approach to mapping exposure and seismic vulnerability of buildings in a context of rapid socioeconomic growth. This approach is a combination of the following interdependent components: (1) extraction of footprint areas of a large number of buildings from high-resolution Google Earth images; (2) estimation of floor numbers of these buildings with an integrated use of high-resolution Google Earth images, Tencent/Baidu Street Views, crowdsourcing data, and associated building-relevant local knowledge; and (3) identification of structural types of these buildings by a combined use of crowdsourcing data and associated building-relevant local knowledge. The efficacy of this “Internet+” approach was demonstrated through an application in Tangshan, China. Field-based verification indicated that the overall mean absolute percentage error of the proposed “Internet+” approach in assessing the total floor area of the addressed buildings was 4.64 %. The verification also showed that the overall consistency between the estimated structural types using the proposed approach and the actual structural types of the buildings with structural type uncertainties could reach 97.54 %, with a kappa coefficient of 0.94. Because of its good accuracy, noteworthy speed, substantial labor savings, negligible cost and distinctive capability in covering large areas in near real time, this “Internet+” approach might have promising prospects in actual seismic loss risk reduction challenges.

     

Discussion on “An analytical approach for the prediction of single pile and pile group behaviour in clay”

In the paper of Sheil and McCabe (2016), the ‘t–z method’ was used to capture the nonlinear response of single pile and pile group. However, some key questions on the skin friction and end resistance were not clearly addressed in their paper. In the present paper, analyses of the load transfer functions of the skin friction and end resistance are discussed in detail.     

An overview of the city of Gweru,Zimbabwe’s water supply chain capacity: towards a demand-oriented approach in domestic water service delivery

Following complaints about water shortages in some areas of Gweru, the paper assessed the availability of enabling capacities to efficiently and sufficiently deliver water to the residents of Gweru in line with the existing level of demand. The key inspected capacity aspects were infrastructure, human resources, finances and physical availability of raw water at source. Purposively selected informants from Zimbabwe National Water Authority (ZINWA) and Gweru city council (GCC) provided data on the infrastructural, financial and human resources situation of GCC. Dam levels data for Gweru’s three supply dams were obtained from ZINWA records through the assistance of Sanyati Catchment Hydrologist. The raw water availability was assessed with the aid of Mann–Kendall test using a 10 years period data set from 2003 to 2012 for trend analysis. Findings revealed that the water sources were not experiencing major changes in water levels, to be precise, the changes were insignificant. However, given the increase in population and demand, any slightest negative change in the supply chain would further widen the gap between supply and demand. The study also uncovered that GCC had challenges in terms of the infrastructure, mainly due to financial constraints. Notably, GCC was not experiencing high staff turnover, but it was however, seriously under staffed and failing to effectively monitor water use in the city. Therefore, strong financial injection is required to support staff and resuscitate the reticulation system. Given the perpetual water shortages in Gweru and the status quo in the supply chain, water demand management strategies, wastewater use and consumer education are consequently proposed as measures that would ensure continuous water supply for all needs in the city.     

Study of subsurface structures using seismic reflection data for Kalar–Khanaqin area/Kurdistan region,Iraq

The study is carried out to detect the subsurface structures that have geological and economic importance by interpreting the available seismic reflection data of an area estimated to be about 1,752 km². The study comprises of the Kalar–Khanaqin and surrounding area, which is located at Zagros folded zone. Twenty-five seismic sections had been interpreted. The total length of all the seismic lines is about 650.4 km. Interpretation of the seismic data is focused on two reflectors, lower Fars and Jeribe formation. The lower Fars reflector picked at the two-way time ranging from 0.1 to 2.6 second, while the Jeribe reflector picked at the two-way time ranging from 1.0 to 2.7 second. The constructed maps denote to the existence of many closed and nose structures, in addition, to numerous fault types. All these features were detected in the area having the NW–SE trend. The depth of the lower Fars formation is ranging from 100.0 to 4,800.0 m, while the depth of the Jeribe formation is ranging from 1,700.0 to 5,000.0 m. The depth maps for the two formations also refer to the similarity of the major geological structures. These structures appear in both formations with existence of slight variation in dimensions. The closed structure no. (1) is located at the north of the study area. The nose structure no. (2) is located at the south of the area. At the west of the area, the elongated structure no. (3). The longitudinal reveres fault intersects the SW limb of the structure. The SW limb of elongated structure no. (4), intersect by longitudinal reveres fault, is located at the east of the area. There is also the semi-closed structure no. (5), which appears at the west of the area around the Qr-1 well. Most of detected faults are of reverse and thrust types having a variable amount of throws and horizontal displacements. Some seismic sections explained the existence of the decollement surface within lower Fars formation, which caused the thrusting and faulting of the overlaying beds.     

Uncertainty Estimation for Resource Assessment—An Application to Coal

The U.S. Geological Survey is conducting a national assessment of coal resources. As part of that assessment, a geostatistical procedure has been developed to estimate the uncertainty of coal resources for the historical categories of geological assurance: measured, indicated, inferred, and hypothetical coal. Data consist of spatially clustered coal thickness measurements from coal beds and/or zones that cover, in some cases, several thousand square kilometers. Our procedure involved trend removal, an examination of spatial correlation, computation of a sample semivariogram, and fitting a semivariogram model. This model provided standard deviations for the uncertainty estimates. The number of sample points (drill holes) in each historical category also was estimated. Measurement error in the thickness of the coal bed/zone was obtained from the fitted model or supplied exogenously. From this information approximate estimates of uncertainty on the historical categories were computed. We illustrate the methodology using drill hole data from the Harmon coal bed located in southwestern North Dakota. The methodology will be applied to approximately 50 coal data sets.     

A model for multiphase flow and transport in porous media including a phenomenological approach to account for deformation—a model concept and its validation within a code intercomparison study

Multiphase flow processes in unsaturated cohesive soils are often affected by deformation due to swelling and shrinking as a result of varying water contents. This paper presents a model concept which is denoted ‘phenomenological’ in terms of the processes responsible for soil deformation, since the effects of deformation on flow and transport are only considered by constitutive relations that allow an adaptation of the hydraulic properties. This new model is validated in a detailed intercomparison study with two state-of-the-art models that are capable of explicitly describing the processes relevant for the deformation. A ‘numerical experiment’ with a state-of-the-art reference model is used to produce ‘measurement data’ for an inverse-modelling-based estimation of the model input parameters for the phenomenological concept.     

A multiphase approach to the stability analysis of reinforced earth structures accounting for a soil–strip failure condition

A multiphase model, developed in the context of elastoplasticity, is applied to the simulation and design of reinforced earth retaining structures. The main feature of this model is to combine the advantage of a homogenization approach, as regards its computational efficiency, with the ability to account for a specific failure condition at the interface between the soil and the reinforcing strips, which may have a decisive influence on the behavior of the structure. A particular emphasis is put on the stability analysis of this kind of reinforced soil structures, formulated within the framework of the yield design theory. Making use of a generalized rigid block failure mechanism, the stability of a reinforced earth retaining wall is investigated by means of the kinematic approach, leading to upper bound estimates for the stability factor of the structure, which are then favorably compared with the results of an elastoplastic analysis. Special attention is paid to assessing in a quantitative way how a specific soil–strip failure condition affects the stability of the reinforced earth structure as a whole.     

Croatia — “a small country for a great vacation”

Croatia is a country of tourism, and this is primarily due to its position by the warm Adriatic Sea, its varying and picturesque landscapes, its diverse and generally favorable climate for tourism, its rich Mediterranean and Central European cultural heritage and its proximity to the leading European consumer countries.In the international tourism market, Croatia presents itself with the slogan A Small Country for a Great Vacation, because its 4.8 million inhabitants and surface area of 56,538 km² place Croatia in the ranks of the world's smaller countries. Its significance is increased by an additional 33,200 km² of territorial waters, of which a large part is considered internal waters because of its location within the limits of a series of islands.The tourism offering of Croatia is very diverse, but its basis is formed by three differing and mutually complimentary regions, through their natural characteristics and cultural heritage: coastal, montane and Pannonian and peri-Pannonian Croatia. The total tourism offering of Croatia includes 900,000 beds, of which over one-fifth are in hotels or similar places, two-fifths are in private rooms and one-third in camps.The tradition of tourism in Croatia is over one hundred years old, and according to the number of foreign tourists it is ranked as the fifth country for tourism in southern Europe.     

An overview of the pegmatitic landscape from the pole to the equator – Applied geomorphology and ore guides

Pegmatites and aplites share the common major constituents with the granitoid suite as well as various gneissic lithologies, e.g., orthogneisses, aplitic gneisses. Not surprising, the pegmatitic landscape has landforms resembling some found in landscapes derived from metamorphic and granitic rocks that genetically next of kin of pegmatites. The wealth of rare minerals, the peculiar shape, the zonation into a rim extremely vulnerable to weathering and a hard silica core renders pegmatites strikingly different from the afore-mentioned crystalline rocks and account for a landscape type of its own. The primary features of pegmatites, shape and composition, the key elements of the CMS classification scheme (Chemical composition-Mineral assemblage-Structural geology) also are critical for the secondary alteration of these rocks and the evolution of a pegmatitic landscape. The 1st order landscape formation, involving geomorphology sensu stricto and weathering contributes to the built-up of five morphological types (erosional type I, alteration type II, mixed type III, composite type IV (erosion-transport-deposition), hidden type V (under an intact roof rock or under clastic overburden)). The minerals produced by chemical weathering are accountable for type II and III, whereas the relic minerals are accountable for type I, III, IV and V. Morphological type IV leads to different placer deposits. The 2nd order landscape formation is governed by the climate giving rise to discrete zones arranged from the pole to the equator and two genetic types, the plain and valley types. Both types can genetically be correlated with the wet-and-dry and the tropical humid climates. Placers developed a clastic apron around pegmatites abundant in relic minerals whereas minerals newly formed during chemical weathering lead to clay deposits resting immediately on top of pegmatites. In terms of applied geomorphology, reading and understanding a pegmatitic landscape means creating an “ore guide” to the pegmatites, to their argillaceous supergene deposits in the apical part and their cogenetic placer deposits around. The current overview is a supplement to the review Dill (2015a).     

Regional vulnerability assessment for debris flows in China—a CWS approach

Based on former conceptual models of vulnerability, this paper aims to improve the quantitative model for regional vulnerability assessment by analyzing in-depth the relation between vulnerability, exposure, coping capacity, and resilience. Taking the mountain settlements in the upper reaches of Min River, China, as a case study, the method of Contributing Weight Superposition (CWS) is applied in establishing both a model and a system for the vulnerability assessment of elements at risk. The CWS approach consists of 13 index factors including population, economic and road densities, building and farmland coverage, hazard-affected areas, urbanization rate, and GDP per capita. Accordingly, a debris flow hazard vulnerability zoning map was obtained and the assessment results show that the distribution of high and comparatively high vulnerability zones, where economic activities are considerably high, has a close correlation to the topography of the catchment and population characteristics. The results thus may serve as a pertinent guidance for settlement relocation, population distribution readjustment, and management to prevent and reduce hazards in the upper reaches of Min River and beyond.     

Deterministic approach to the seismic hazard of dam sites in Kızılırmak basin,Turkey

Dams constructed on the seismically active regions have a high-risk potential for downstream life and property. Strong ground motion can result in instability of the dam and strength loss of foundation. Active faults within the foundation of dam have the potential to cause damaging displacement of the structures. Appropriate design measures should be considered to obtain rational solution to the problem of catastrophic release of water from the reservoir, and especially to resist earthquake loads. Safety concerns for dams under the earthquake loads involve the seismic hazard evaluation of dam site for the overall stability of structure. Various types of analyses can be used, ranging from a simplified analysis to more complex procedures based on ground motion parameters and response spectra. This paper briefly evaluates seismic hazard analyses for dam structures, and introduces the analyses for thirty-six dams with height ranging from 15 to 195 m in Kızılırmak basin, Turkey. The seismic hazard analyses have indicated that peak ground acceleration varies within a wide range (0.09–0.45 g) for the dam sites of the basin.     

Groundwater of Egypt: “an environmental overview”

Although Egypt has the great Nile River, which is the main supply of water, Egypt’s water is limited to 55.5 billion m³ per annum. Owing to the rapid growth of the population and the increasing consumption of water in agriculture, industry, domestic use, etc., it is expected that Egypt will rely to some extent on groundwater to develop the new projects such as Tushka in Upper Egypt and East Oweinat. Issues related to groundwater in Egypt are identified with the common geological features associated with formation of the aquifers and demonstrating the location of the main resources of groundwater, followed by the main objective of this paper, which is addressing the environmental issues related to groundwater in Egypt. Several studies have been reviewed and personal communication made with the authorities to introduce this work and provide an overview of the groundwater quality problems in Egypt with examples from different parts of the country.     

Erratum to: “Mantle depth facies of high-pressure pyroxene in the Kola region”

Doklady Earth Sciences -     

Linking earthquake-triggered paleolandslides to their seismic source and to the possible seismic event that originated them in a portion of the Argentine Precordillera (31°–33°S)

Natural Hazards - A total of 36 rock slides were selected for analysing a probable seismic source in the active Andean Precordillera (31°–33°S), the most seismic region of...