Modelling of karstification

Kaufmann, Georg; Romanov, Douchko

Modelling long-term and short-term evolution of karst in vicinity of tunnels Journal Article

Journal of Hydrology, 581 , pp. 124282, 2020.

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Kaufmann, Georg; Romanov, Douchko

Karst and trains: The challenge of railway tunneling Inproceedings

Geophysical Research Abstracts, pp. EGU2019-3554, 2019.

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The strength and speed of karstification depends on various parameters, such as water balance or the existing rocks. A karstification model was used to model how karstification had developed in the area of the Schalkauer Platte and how it will develop in the future.

The model shows regional differences in the karstification potential. Especially in the areas where the model calculated increased karstification, there are, indeed, more caves, including the Blessberg cave. The modelling of future karst development, especially in the area of the cave part under the tunnel that was blocked during tunnel construction, showed a substantial increase in karstification in this area, i.e., a faster widening of fissures and crevices (in the time frame of 100 to 200 years).

Biomineralisation of calcite by bacterial isolates

Keiner, Robert; Frosch, Torsten; Hanf, Stefan; Rusznyak, Anna; Akob, Denise M; Küsel, Kirsten; Popp, Jürgen

Raman Spectroscopy—An Innovative and Versatile Tool To Follow the Respirational Activity and Carbonate Biomineralization of Important Cave Bacteria Journal Article

Analytical Chemistry, 85 (18), pp. 8708–8714, 2013.

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Rusznyák, Anna; Akob, Denise M; Nietzsche, Sándor; Eusterhues, Karin; Totsche, Kai Uwe; Neu, Thomas R; Frosch, Torsten; Popp, Jürgen; Keiner, Robert; Geletneky, Jörn; Katzschmann, Lutz; Schulze, Ernst-Detlef; Küsel, Kirsten

Calcite Biomineralization by Bacterial Isolates from the Recently Discovered Pristine Karstic Herrenberg Cave Journal Article

Applied and Environmental Microbiology, 78 (4), pp. 1157–1167, 2012.

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Using stalactite material and fluvial sediments from the Blessberg cave, the diversity and activity of the occuring bacteria and their formation of carbonate minerals were investigated. For this purpose, various techniques such as phylogenetic analyses, bacterial cultivation, electron microscopy, X-ray spectroscopy, confocal laser scanning microscopy, and Raman spectroscopy were used.

Bacteria were found on the surface and inside the stalactites using confocal laser scanning microscopy. Phylogenetic analyses showed that Proteobacteria were most abundant in the bacterial communities on and inside the stalactites and also in the fluvial sediments, but also other groups such as Actinobacteria or FirmicutesFirmicutes Eine artenreiche Gruppe innerhalb der Bakterien. Unterscheiden sich von den Actinobakterien unter anderem durch ihren niedrigeren Gehalt an Nukleinbasen in der Bakterien-DNS.. Many of the detected bacteria have not yet been cultivated.

A total of nine new bacterial cultures were isolated from the cave sediments, growing on alkaline carbonate-precipitating medium and belonging to the bacterial genera Arthrobacter, Flavobacterium, Pseudomonas, Rhodococcus, Serratia and Stenotrophomonas. Of these, the two with the most intense precipitate formation were selected for further research: Arthrobacter sulfonivorans SCM3 and Rhodococcus globerulus SCM4. Both produced extracellular polymeric substances (EPS) and grew as cell aggregates.

Scanning electron microscopy of cell aggregates and extracellular polymeric substance (EPS) of the isolates Arthrobacter sulfonivorans SCM3 and Rhodococcus globerulus SCM4
Scanning electron microscopy of cell aggregates and extracellular polymeric substance (EPS) of the isolates Arthrobacter sulfonivorans SCM3 (left) and Rhodococcus globerulus SCM4 (right) (Image: Elektronenmikroskopisches Zentrum Jena, Sándor Nietzsche and Anna Rusznyak).

The carbonate minerals formed were mixtures of calcite, vaterite, and monohydrocalcite. Arthrobacter sulfonivorans SCM3 formed xenomorphic spherical crystals, and Rhodococcus globerulus SCM4 idiomorphic crystals with rhombohedral morphology.

The biomineralisation process of Arthrobacter sulfonivorans SCM3 was further investigated using a combination of Raman macro- and microspectroscopy to obtain a spatially resolved chemical representation of the different types of calcium carbonate minerals. The cell surface of Arthrobacter sulfonivorans SCM3 served as a nucleus for the biomineralisation of vaterite precipitates. These were initially spherical and then continued to grow as chemically stable, rock-forming calcite crystals with rough edges.

Scanning electron microscopy of precipitates of the isolates Arthrobacter sulfonivorans SCM3 and Rhodococcus globerulus SCM4
Scanning electron microscopy of precipitates of the isolates Arthrobacter sulfonivorans SCM3 (left) and Rhodococcus globerulus SCM4 (right) (Image: Elektronenmikroskopisches Zentrum Jena, Sándor Nietzsche and Anna Rusznyak).

First Reconstruction of the Holocene Climate

Breitenbach, Sebastian F. M.; Plessen, Birgit; Wenz, Sarah; Leonhardt, Jens; Tjallingii, Rik; Scholz, Denis; Jochum, Klaus-Peter; Marwan, Norbert

A multi-proxy reconstruction of Holocene climate change from Blessberg Cave, Germany Inproceedings

Geophysical Research Abstracts, pp. EGU2016-14213, 2016.

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The first results of the geochemical analyses of the three stalagmites BB-1 to BB-3 already allow conclusions about the climatic changes of the last 14,000 years. A detailed interpretation can be found in the article Climate zone shift in Central Europe.

First results of analyses of BB-1 to BB-3

Novel methods for studying palaeoclimate dynamics

Marwan, Norbert; Kraemer, Kai Hauke; Wiesner, Karolin; Breitenbach, Sebastian F. M.; Leonhardt, Jens

Recurrence based entropies Presentation

07.05.2019, (Fourth International Conference on Recent Advances in Nonlinear Mechanics, Łódz (Poland)).

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Marwan, Norbert; Kraemer, Kai Hauke; Wiesner, Karolin; Breitenbach, Sebastian F. M.; Leonhardt, Jens

Recurrence based entropies Inproceedings

Geophysical Research Abstracts, pp. EGU2019-2817, 2019.

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At PIK, among other things, new methods are being developed that, on the one hand, can be used to investigate new aspects in palaeoclimate data, but on the other hand can also cope with the difficulties usually associated with palaeoclimate analyses – such as gaps in data series, uncertainties in the dating, or irregularities in the data sampling. Although this is basic research, it is also immediately applied to interesting questions.

In this example, a method was developed to determine the regularity of certain recurring pattern in the data. The technical terms here are “recurrence” and “entropy” (a measure of disorder). Methods that look for recurring patterns are used in various disciplines, not only in the geosciences, but also in medicine, mechanical engineering, finance, and so on. Besides finding abrupt changes, they are also used for comparing different data sets or for classification (e.g. for machine learning).

The newly developed method was applied to the carbon isotopeIsotop Chemische Elemente können aus verschieden aufgebauten Atomen gebildet sein. Die Anzahl Protonen im Atomkern ist zwar dabei gleich, aber die Anzahl der Neutronen kann variieren. Man spricht dann von Isotopen, deren Massen kleine, aber messbare Unterschiede aufweisen. Der Atomkern des Sauerstoffs besteht z. B. aus 8 Protonen und in der Regel aus 8 Neutronen. Es gibt aber auch Sauerstoff, dessen Kerne aus 8 Protonen und 9 oder 10 Neutronen bestehen (neben selteneren, instabilen Sauerstoffisotopen). Um das zu kennzeichnen, gibt man zusätzlich zum chemischen Symbol noch die Massenzahl (Summe aus Protonen und Neutronen) an, also 16O, 17O oder 18O. Die unterschiedlichen Isotope verhalten sich zwar chemisch identisch, physikalisch aber - aufgrund ihres unterschiedlichen Gewichtes - leicht unterschiedlich. Damit stellen sie äusserst wertvolle Marker dar, die uns wichtige Hinweise zur Änderung des Klimas, der Umgebungsvegetation, Bodenaktivität und vielem mehr geben. data from BB-1 and BB-3 (for this purpose, the data from both stalagmites were combined into one long data series using a special procedure). Interestingly, there are regular differences during the influence of the maritime climate (Atlantic influence) and during the influence of the continental climate. During the Atlantic influence, the climate seems to have changed more regularly than during the dominant continental climate (this may be related to the regular change of cold events in the North Atlantic, so-called “Bond events”, or to the North Atlantic Oscillation). This could be used to extend our knowledge about the migration of the climate zone boundary, as known for the last 4,000 years (see Climate Zone Shift in central Europe), further into the past. Whenever the new measure indicates that there were more regular climate dynamics, the climate zone boundary was further east of the Bleßberg Cave.

Abrupt Climate Change

Marwan, Norbert; Breitenbach, Sebastian F. M.; Plessen, Birgit; Scholz, Denis; Leonhardt, Jens

Recurrence properties as signatures for abrupt climate change Inproceedings

Geophysical Research Abstracts, pp. EGU2014-8893, 2014.

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Among other things, new methods are being developed at PIK that, on the one hand, investigate new aspects in palaeoclimate data, but also cope with the difficulties usually associated with palaeoclimate analyses – such as gaps in the data, age uncertainties, or irregularities in the data sampling. While this is basic research, it is also immediately applied to interesting research questions.

One focus is the development and application of methods that specifically investigate recurring patterns. These methods are very successful for finding abrupt changes, but also for comparing different data sets, e.g., to detect mutual influences.

In one of our first analyses of the three stalagmites BB-1 to BB-3, we had looked at the oxygen isotopes of BB-1 with recurrence based methods. Thereby we had explicitly considered dating uncertainties. Due to the dating uncertainties there are small shifts of the time series along the x-axis. Therefore, within the uncertainties, different realizations of the course of the measured oxygen isotopes are possible.

Sauerstoffisotope von BB-1
Oxygen isotopes of BB-1. Due to the dating uncertainties, there are several possibilities when changes in this climate archive happened. The stalagmite grew from about 6,000 years ago to about 400 years ago.

The recurrence patterns are examined with a special analysis tool, the so-called “recurrence plot”. This can be used to plot times when similar states have occurred. The patterns seen in such a recurrence plot have a deeper meaning and can be further analyzed and quantified to find changes in the dynamics of the underlying process.

Recurrence plot der Sauerstoffisotope von BB-1
Recurrence plot of one realization of the measured oxygen isotopes in BB-1.

The numerical analysis of recurrence plots yields various results that shed light on different aspects of climate dynamics. Two such results are briefly presented here: on the one hand, the complexity of climate variability (“transitivityTransitivity Ein Maß aus der Netzwerktheorie, welches quantifiziert, wie stark sich Zustände zu kleinen Gruppen zusammenfinden.”) and, on the other hand, how well such a climate signal would be predictable (“determinismDeterminism Ein Maß aus der Wiederkehr-Analyse, welches beschreibt, wie gut sich die Veränderung eines Systems vorhersagen läßt.”). Both results show a general tendency towards greater complexity and lower predictability for younger ages. However, they also show short-lived increases to better predictability for certain time points, namely about 4,200, 2,800, and 1,400 years ago. It was precisely at these times that short-lived and rapid glaciations occurred in the North Atlantic, the so-called “Bond events.” Moreover, there are variations in the complexity of the climate signal (“transitivity”), but these variations are within the range of uncertainty (confidence interval), so we cannot really interpret them.

Recurrence quantification der Sauerstoffisotope von BB-1
Quantitative analysis of recurrence patterns in oxygen isotopeIsotop Chemische Elemente können aus verschieden aufgebauten Atomen gebildet sein. Die Anzahl Protonen im Atomkern ist zwar dabei gleich, aber die Anzahl der Neutronen kann variieren. Man spricht dann von Isotopen, deren Massen kleine, aber messbare Unterschiede aufweisen. Der Atomkern des Sauerstoffs besteht z. B. aus 8 Protonen und in der Regel aus 8 Neutronen. Es gibt aber auch Sauerstoff, dessen Kerne aus 8 Protonen und 9 oder 10 Neutronen bestehen (neben selteneren, instabilen Sauerstoffisotopen). Um das zu kennzeichnen, gibt man zusätzlich zum chemischen Symbol noch die Massenzahl (Summe aus Protonen und Neutronen) an, also 16O, 17O oder 18O. Die unterschiedlichen Isotope verhalten sich zwar chemisch identisch, physikalisch aber - aufgrund ihres unterschiedlichen Gewichtes - leicht unterschiedlich. Damit stellen sie äusserst wertvolle Marker dar, die uns wichtige Hinweise zur Änderung des Klimas, der Umgebungsvegetation, Bodenaktivität und vielem mehr geben. measurements of BB-1.

Climate Zone Shift in central Europe

Breitenbach, Sebastian F. M.; Plessen, Birgit; Waltgenbach, Sarah; Tjallingii, Rik; Leonhardt, Jens; Jochum, Klaus-Peter; Meyer, Hanno; Goswami, Bedartha; Marwan, Norbert; Scholz, Denis

Holocene interaction of maritime and continental climate in Central Europe: New speleothem evidence from Central Germany Journal Article

Global and Planetary Change, 176 , pp. 144–161, 2019.

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Breitenbach, Sebastian F. M.; Plessen, Birgit; Wenz, Sarah; Leonhardt, Jens; Tjallingii, Rik; Scholz, Denis; Jochum, Klaus-Peter; Marwan, Norbert

A multi-proxy reconstruction of Holocene climate change from Blessberg Cave, Germany Inproceedings

Geophysical Research Abstracts, pp. EGU2016-14213, 2016.

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BB-1, BB-2 and BB-3.
BB-1, BB-2 and BB-3.

The three stalagmites BB-1 to BB-3 were geochemically investigated by GFZ Potsdam, Ruhr-Uni Bochum, PIK Potsdam, Uni Mainz and Northumbria University.

The dating was done at the University of Mainz. Stalagmite BB-1 grew 5,600 to 600 years ago, BB-2 6,200 to 3,700 years ago, and BB-3 (although the shortest) 11,200 to 5,300 years ago. At GFZ, carbon and oxygen isotopes (δ13C and δ18O) were measured in over 1,000 samples in BB-1, and about 400 and 540 samples each in BB-2 and BB-3. In parallel, the distribution of various elements was measured by X-ray analysis. Age modelling and statistical analysis were carried out at Ruhr-Uni Bochum, PIK Potsdam and Northumbria University.

In the age models of stalagmites BB-1 and BB-3, abrupt changes from slow to fast growth are evident at about 5,900 BC and from fast to more slow growth at about 2,600 BC.

Age model of BB-1 and BB-3
Age models of stalagmites BB-1 and BB-3. Changes in growth rates at around 6,200 BC and between 5,900 and 2,600 BC can clearly be seen, for which climatic changes are responsible.

The temporal changes in isotope ratios were compared with palaeoclimate data from the Bunker Cave in North Rhine-Westphalia and from Greenland.

Carbon and oxygen istotopes of BB-1 and BB-3
Isotope ratios in stalagmites BB-1 and BB-3 (combined). The longer-term trends probably reflect a change in solar influence. The short-term climate cooling around 6,200 BC is clearly visible in the isotope ratios. The abrupt drop in δ18O values around 900 to 1,200 AD coincides with the Medieval Warm Period.

This comparison allows an estimation of the spatial distribution of the influence of the maritime, humid and warm Atlantic climate in Central Europe. The Blessberg cave is located at the border between the influence of the Atlantic climate and the continental, drier and colder climate from the east. From the alternation between stronger similarities and greater differences in the regional climate at the Blessberg Cave and the Bunker Cave it can be determined when the climate zone boundary was east or west of the Bleßberg Cave, i.e. when the Atlantic, wetter and warmer climate and when the colder and drier continental climate prevailed over the Bleßberg Cave. This analysis could be carried out back to about 4,000 years ago (i.e. about 2050 BC). Before this time, due to the lack of data from Greenland, it is not yet possible to make conclusions regarding the location of the climate zone boundary, but at least around this time the Bleßberg Cave was probably under the influence of the Atlantic climate. Around 1850 BC it then changed to a continental climate (in the late Aunjetitz culture, known from the Nebra sky disc). Between 950 and 850 BC, the Atlantic influence became more dominant again (towards the end of the Urnfield Culture).

Karte der Verlagerung der Klimazonengrenze.
Shift of the climate zone boundary (dashed) to the east with hypothetical course (dotted) at the time of the Urnfield Culture (BU – Bunker Cave, BBH – Blessberg Cave).