Estimating the upper limit of prehistoric peak ground acceleration using an in situ, intact and vulnerable stalagmite from Plavecka priepast cave (Detrekoi-zsomboly), Little Carpathians, Slovakia-first results

Earthquakes hit urban centres in Europe infrequently, but occasionally with disastrous effects. Obtaining an unbiased view of seismic hazard (and risk) is therefore very important. In principle, the best way to test probabilistic seismic hazard assessments (PSHAs) is to compare them with observations that are entirely independent of the procedure used to produce PSHA models. Arguably, the most valuable information in this context should be information on long-term hazard, namely maximum intensities (or magnitudes) occurring over time intervals that are at least as long as a seismic cycle. The new observations can provide information of maximum intensity (or magnitude) for long timescale as an input data for PSHA studies as well. Long-term information can be gained from intact stalagmites in natural caves. These formations survived all earthquakes that have occurred over thousands of years, depending on the age of the stalagmite. Their 'survival' requires that the horizontal ground acceleration (HGA) has never exceeded a certain critical value within that time period. Here, we present such a stalagmite-based case study from the Little Carpathians of Slovakia. A specially shaped, intact and vulnerable stalagmite in the Plavecka priepast cave was examined in 2013. This stalagmite is suitable for estimating the upper limit of horizontal peak ground acceleration generated by prehistoric earthquakes. The critical HGA values as a function of time going back into the past determined from the stalagmite that we investigated are presented. For example, at the time of Joko event (1906), the critical HGA value cannot have been higher than 1 and 1.3 m/s(2) at the time of the assumed Carnuntum event (similar to 340 AD), and 3000 years ago, it must have been lower than 1.7 m/s(2). We claimed that the effect of Joko earthquake (1906) on the location of the Plavecka priepast cave is consistent with the critical HGA value provided by the stalagmite we investigated. The approach used in this study yields significant new constraints on the seismic hazard, as tectonic structures close to Plavecka priepast cave did not generate strong earthquakes in the last few thousand years. The results of this study are highly relevant given that the two capitals, Vienna and Bratislava, are located within 40 and 70 km of the cave, respectively.Web of Science2151130111

Ověření možností využití pěnové separace pro odstranění dehtových a olejových látek z předčištěných fenolčpavkových vod

Import 20/04/2006Prezenční výpůjčkaVysoká škola báňská. Fakulta hornicko-geologická. Katedra (525) úpravnictví a technologií pro ochranu životního prostřed

A small-scale landslide susceptibility assessment for the territory of Western Carpathians

This study presented herein compares the bivariate and multivariate landslide susceptibility mapping methods and presents the landslide susceptibility map of the territory of Western Carpathians in small scale. This study also describes pioneer work for the territory of Western Carpathians, overreaching state borders, using verified sophisticated statistical methods. In the susceptibility mapping, digital elevation model was first constructed using a GIS software, and parameter maps affecting the slope stability such as geology, seismicity, precipitation, topographical elevation, slope angle, slope aspect and land cover were considered. In the last stage of the analyses, landslide susceptibility maps were produced using bivariate and multivariate analyses, and they were then compared by means of their validations. The validation of the bivariate analysis data was performed using the results of bivariate analysis for landslide areas of Slovakia containing five classes of susceptibility in scale 1:500,000. The validation area is the area of Western Carpathians within Slovakia. Eighty-two per cent of area does not differ in more than one class. The validation of the multivariate analysis data was performed using the results from the Kysuce region in the northern part of Slovakia in scale 1:10,000. The raster calculator was used to express the difference between each pair of pixels within these two layers. Seventy-seven per cent of the pixels do not differ in more than 25 %, 94 % of the pixels do not differ in more than 50 %. The maximal possible difference is 100 % (one pixel with value 0 and other with value 1, or vice versa). Receiver operating characteristic analysis was also performed, the area under curve value for bivariate model was calculated to be 0.735, while it was 0.823 for multivariate. The results of the validation can be considered as satisfactory.Web of Science6911107108

Utilization of ground subsidence caused by underground mining to produce a map of possible land-use areas for urban planning purposes

The presented work deals with a new type of map titled—a map of a possible area use for planned built-up area purposes in areas affected by underground mining-related subsidence. Generally, accepted theory of a subsidence basin must be applied to such areas, and in order to produce the map, ground subsidence isolines, land-use plan, and slope deformation distribution were considered. The map can be used by land-use planners, future developers, investors, engineering geologists, etc. to inform future development of such land. It is clear that land-use planners may not have sufficient knowledge to decide whether the ground subsidence value is acceptable or not for a particular development purpose. At the same time, it shows that the existence of slope deformations also influences the siting of new buildings in undermined areas and therefore these were included in the map compilation process. The outcome is three area categories where mining subsidence impacts surface development, namely—low influence on the planned development, economically acceptable influence on the planned development, and extreme influence with development prohibited. The research was carried out in the Darkov Region in the northeast of the Czech Republic, where black coal is mined and extensive mining impact on the surface identified. The map produced in this study will help the controlled development of the region by means of appropriate land-use planning.Web of Science8158857

Monitoring and analysis of burning in coal tailing dumps: a case study from the Czech Republic

The tailings are significant geological environments in mining and industrial regions. They represent special engineering-geological zones of anthropogenic sediments that require specific engineering-geological investigation. In particular, it is important to examine the sites in detail with regard to their potential heterogeneity. The article deals with an important engineering-geological issue of burning in coal mine and coal tailing dumps. A case study was implemented in a tailing dump in Heřmanice located in Ostrava which is a major industrial city of the Czech Republic. In this urban agglomeration, anthropogenic sediments form 20 % of all foundation soils. Thermometric monitoring in Heřmanice detected a thermally active coal tailing dump with burning as deep as 9 m. The burning is predominantly related to the content of oxygen in the body of the tailing. It belongs to the limiting conditions of the pyrophoric and consequently self-sustained burning. Other factors are sufficient contents and quality of coal mass and capacity to accumulate thermal energy of exothermal reactions. Dynamics of changes in the burning processes were identified in dependence on time, depth and distribution. There was a considerable heterogeneity of thermal activity as for all parameters, and changes were observed from the point of view of time. Considering the depth, burning gradually spread deeper. However, in the depth of 12 m, no significant thermal activity was observed within the overall studied locality. It may be stated that thermal activity is observed as much as 40 % of the studied area. Directionally, there was a progression of the process from west to east. The identified facts may be applied in final designed levels of coal tailing dumps where observational experiences identified intense cooling up to the height of 5 m preventing higher stages of self-ignition process (best situation). Tailing dumps from 5 to 12 m may already be thermally active (meeting other boundary conditions), and in tailing dumps over 12 m, it is clear that there is no thermal activity below 12 m.Web of Science73106612660

In-situ remediation of the contaminated soils in Ostrava city (Czech Republic) by steam curing/vapor

This study deals with an application of vapor in the remediation of soils in an extensive part of the Ostrava city center (Czech Republic) needed to be decontaminated from abundant tar (wash oil). The source of contamination was the Karolína Coking Plant (operating between 1842 and 1985), which was situated in the center of the Ostrava City, the largest industrial center of the Czech Republic and former Czechoslovakia. The problem was that a large part of the contaminated ground could not be remediated by extraction and soil treatment, but the area needed to be remediated without disrupting its structure by reason of impossibility of the changes to the important Road of 28 Října and Na Karolíně Street and historical buildings in the city center. The main scientific contribution of this article is to point at a possible application of this unique solution in localities where no soils/rocks can be extracted during remediation. The remediation process in this study was successfully completed and the monitoring results confirmed that the unsuitable conditions were improved. Successful application of the vapor in remediation of contaminated soils in this study may expand new horizons in applications for numerous contaminated city quarters world-wide.Web of Science154554

Monitoring of heat transmission from buildings into geological environment and evaluation of soil deformation consequences in foundation engineering

In engineering geology a number of factors affecting foundation conditions are taken into consideration during engineering-geological investigations. This article deals with the factor of heat sourced from a structure (brick kiln) as a restrictive factor in foundation engineering in clay soils and introduces a documentation of soil deformation observations as an impact of the heat transmission into the geological environment. It was carried out in Southern Moravia in the Czech Republic, where the dominant foundation soils are Neogeneous clays where differential settlements of a tunnel kiln structure occurred as a result of ignoring the boundary conditions of temperature changes in the soil environment. The brick kilns caused heterogeneous spatial changes in the subsoil temperatures. This consequently resulted in differential settlements due to temperature changes originating from the kilns. The differential settlements reached as much as 150 mm. The major objective of the article is to highlight the importance of the heat transmission from buildings into the geological environment as a factor which should be considered in engineering geology and its application in planning. A new procedure for reducing or elimination of ground movements sourced from underlying clayey soils depending on the heat changes was also suggested in this context.Web of Science7282955294

Unique documentation, analysis of origin and development of an undrained depression in a subsidence basin caused by underground coal mining (Kozinec, Czech Republic)

This article aims to explain and demonstrate the origin and development of a subsidence basin caused by coal mining as well as to point out important aspects of this phenomenon in engineering geology. Engineering geology needs to deal with a number of issues related to the origin and development of subsidence basins in areas affected by deep coal mining. An interesting case study from the Upper-Silesian Basin in the northeast of the Czech Republic near the Polish border is presented in this paper. There is a clear time chronological succession in the ground surface changes manifested by a ground subsidence gradation, both in their absolute values as well as in their spatial distribution. The phenomenon is documented by aerial photo time series, which optimally depict the origin and development of the subsidence. In the study area, there are changes in the landscape elements and it is essential to be considered in future land use plans. The marginal conditions of the Quaternary geological structure and hydrogeological conditions are responsible for an unconfined aquifer which manifests there as a water body in an undrained depression in the course of the ground subsidence.Web of Science721201