Upper Silesian Information System about sinkhole hazards and its use in the fighting of exothermic processes in abandoned coal mines at Katowice area

Górnośląski System Informacji o Zagrożeniach Zapadliskowych ([email protected]) jest platformą internetową udostępniającą użytkownikom dane o geograficznym położeniu rejonów dokonanej i zakończonej płytkiej eksploatacji górniczej węgla kamiennego, rud cynku i ołowiu oraz obiektów górniczych (szybów, sztolni) zbudowanych w przeszłości dla udostępnienia złóż tych surowców w obszarze Górnego Śląska. Dane te można wykorzystywać do analiz, badań oraz projektowania działań zmierzających do neutralizacji zagrożeń dla użytkowania terenów zlikwidowanych kopalń węgla kamiennego. Jednym z takich zagrożeń jest utlenianie i spalanie się węgla kamiennego pozostawionego w złożach i związane z nim zmiany warunków geotermicznych w obszarach zlikwidowanych kopalń. Konsekwencją procesów egzotermicznych zachodzących w węglu jest wydzielanie się gazów do atmosfery i deformacje powierzchni. W artykule przedstawiono analizę takiego zagrożenia na terenach północnej części miasta Katowice (dzielnice Wełnowiec-Józefowiec, Dąb, Koszutka i Bogucice), w oparciu o informację geologiczną, górniczą oraz 11 udokumentowanych przypadków wystąpienia zjawisk egzotermicznych na tym obszarze. Wszystkie przypadki wystąpiły w latach 1977 - 2018 na terenach dokonanej płytkiej eksploatacji węgla kamiennego. Ich efektem było wydzielanie się toksycznych gazów do atmosfery, a w czterech przypadkach deformacje podłoża obiektów budowlanych.Upper Silesian Information System about Sinkhole Hazards ([email protected]) is an Internet platform providing users with data on the geographical location of the completed shallow coal and zinc/lead ore mining likewise about location of mining facilities (shafts, tunnels) built in the past to provide access to these deposits in the area of Upper Silesia. These data can be used for analysis, research and design of activities for the purposes of eliminating threats to the use of post-mining areas. One of such threats is the spontaneous oxidation and combustion of coal left in deposits and changes in geothermic conditions in the abandoned mines. The consequence of exothermic processes occurring in coal is the release of gases into the atmosphere and surface deformations. The paper presents such hazard analysis for the northern part of the city of Katowice (Wełnowiec-Józefowiec, Dąb, Koszutka and Bogucice quarters) based on geological and mining information as well as 11 cases of exothermic processes occurrence in this area. All these phenomena occurred in the years 1977 - 2018 in the areas of shallow coal exploitation. Their effect was the release of toxic gases into the atmosphere and in four cases the occurrence of deformation of the structures’ subsoil

Gravimetric and hydrometric system for monitoring of mining tremors in Upper Silesia

The article presents the characteristics of the gravimetric and hydrometric system for observation of mining tremors in Upper Silesia. Individual system components were installed in the years 2018-2019 as part of the European Platform Observing System -Poland project with the acronym EPOS-PL, financed from the EU program - Intelligent Development. The system records the changes in gravitational acceleration and groundwater level with a frequency of 1 Hz in the mining and post-mining areas. The analysis of the measurement data collected allows evaluating the sensitivity of the system and the possibilities of its use in the mining seismicity studies in Upper Silesia, as well as monitoring rock mass movements under the influence of seismic and geodynamic phenomena in other parts of the world

Upper Silesian Geophysical Observation System - a unit of the EPOS project

The aim of the paper is to present the structure and research potential of the newly created measurement and information system for observing dynamic phenomena occurring in the Earth's crust in the Upper Silesian Coal Basin (USCB) in Poland as a result of mining activities. The structure of the system is similar to the one developed for monitoring the movements of the European tectonic plate under the European Plate Observation System (EPOS) programme. The measurement part of the system consists of stationary devices and sensors working in monitoring mode, installed in various locations of the USCB, both on the surface and underground, as well as data sets from periodically performed measurements using land, air and satellite techniques. The IT part of the system will create a local data centre with specialized and dedicated processing and modelling software in which all measurement data will be archived and processed to a form which enables the analysis of the short and long-term impact of mining operations on the environment. As one of the elements of the system will be observations of the short and long-term gravity and morphology changes, the collected data will enable research in the field of the geodynamics of mining areas to be conducted

PostMinQuake: Seismicity of selected closed European hard coal mines during flooding

Durch den Abbau von Steinkohle entstehen große unterirdische Hohlräume, die den Untergrund und die Landoberfläche erheblich beeinträchtigen. Beobachtungen des Verhaltens der Landoberfläche nach der Schließung von Bergwerken zeigen, dass diese Gefahren nicht verschwinden. In der Nachbergbauphase kommt es zu einem Grubenwasseranstieg in untertägigen Kohlebergwerken. Hierbei fließt das Wasser in den offenen Grubenbau und andere veränderte oder durchbrochene Bereiche.In diesem Beitrag werden die ersten Erkenntnisse aus dem PostMinQuake-Projekt vorgestellt. Dieses zielt darauf ab, Mechanismen, relevante Parameter und Abhängigkeiten von bergbaulichen und geologischen Parametern zu ermitteln, die in mehreren europäischen Kohleregionen Seismizität nach dem Abbau verursachen. Außerdem wird die Korrelation zwischen Seismizität und Grundwasserspiegel in den untersuchten Gebieten dargestellt, die während der Nachbergbauphase beobachtet wurde. Dabei wird aufgezeigt, dass es notwendig ist, neue Maßnahmen zur Überwachung dieser seismischen Ereignisse einzuführenMining of hard coal creates large underground cavities, which significantly affect the subsurface and land surface. Observations of land surface behaviour after the closure of mines demonstrate that these threats do not disappear. During mine water rebound in the post-mining phase of underground coalmines, the water flows into the open mine workings and other altered or fissured areas.This paper provides early observations from the PostMinQuake project, which is designed to identify mechanisms, relevant parameters and dependencies of mining and geological parameters causing post-mining seismicity in several European coal regions. It also presents the correlation between seismicity and water table level in the studied basins that has been observed during the post-mining phase and shows the necessity of implementing new procedures to monitor these seismic event

European feedback on post-mining seismicity

Following the Paris Agreement adopted in 2015, Europe has committed to reducing its greenhouse gas emissions. In this context, the abandonment of coal as an energy source, both in terms of consumption and production, will lead to the closure of many mines in the years to come. Mine closure guidelines to manage residual mining risks already exist in European countries. However, they do not include post-mining seismic risk management due to a lack of sufficient studies and knowledge on this subject. After mining closure, the flooding of the mining works leads to hydromechanical loading of the underground and, in the longer term, to diffusion and an increase in the pore pressure. These conditions can lead, in certain situations, to the reactivation of tectonic faults, which may cause seismic events strong enough to be felt on the surface or even produce damage. Events of lower magnitudes, usually attributed to the remobilization of old mining works, are referred to as postmining seismic hazards. The European RFCS PostMinQuake project, which started in 2020, aims to study this hazard at five mining basins located in France, Germany, Poland and the Czech Republic, known to have experienced significant seismicity during their operation. This analysis, based on the feedback of the partners of the project, aims to frame an inventory of the five studied mining basins, which all encounter post-mining seismicity problem today. Three basins out of five show events with local magnitudes of the order of 3 to 3.5, which took place between nine and thirteen years after the closure of the mines. Even though the magnitudes of these earthquakes are small to moderate, they are felt on the surface as they occur at shallow depths. In all of the considered countries, a national seismological network exists, however, none of them is fully dedicated to post-mining seismic monitoring. These networks generally consist of a sparse mesh of stations, which does not allow the detection of events of magnitude less than 1 and the location of events have high spatial uncertainties. France is not an exception, but it relies on microseismic monitoring to detect early signs of instability at the level of mining structures and to anticipate the possible appearance of surface disorders. Out of the five basins that are studied, the Gardanne basin, which has been monitored since 2008, is the most documented case study of post-mining seismicity. This article also shows the difficulty in identifying the key conditions and factors that can lead to the remobilization of faults