The aim of the research is to quantify weathering in the form of cavity formation, cavity filling and surface denudation in karst.
Quantitative climate reconstruction for Marine Isotope Stage 3
DFG Project: Quantitative climate reconstruction for MIS 3MIS 3 "MIS" ist die Abkürzung für "marine isotope stage", übersetzt also "Isotopenstadium mariner Sedimente". Da sich beim Wechsel von Warm- zu Kaltzeiten (und umgekehrt) die Isotopenverhältnisse in den Kalkschalen kleiner Einzeller (Foraminiferen) auf dem Meeresboden ändern, werden diese zur Datierung herangezogen und lassen sich zur Eingruppierung verschiedener Klimazustände in der Vergangenheit nutzen. "MIS 3" bedeutet dabei eine kurzzeitige Warmphase (beginnend vor 57 Tausend Jahren) während der letzten Eiszeit. in Central Europe based on multi-proxyProxy Umwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. data from precisely dated speleothems (flowstones) from Bleßberg Cave, Germany
Project lead
- Johannes Gutenberg University Mainz, Institute of Geosciences – Isotope-geochemical Palaeoclimatology/Speleothem Research
Involved Partners
- Northumbria University Newcastle, Geography and Environmental Sciences – Cold and Palaeo Environments Group
- Potsdam Institute for Climate Impact Research (PIK) – Group Development of advanced time series analysis techniques
- Geoforschungszentrum Potsdam (GFZ) – Group stable isotopes (sediments and water)
Content
The last glacial period and in particular the Marine 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. Stage (MISMIS "MIS" ist die Abkürzung für "marine isotope stage", übersetzt also "Isotopenstadium mariner Sedimente". Da sich beim Wechsel von Warm- zu Kaltzeiten (und umgekehrt) die Isotopenverhältnisse in den Kalkschalen kleiner Einzeller (Foraminiferen) auf dem Meeresboden ändern, werden diese zur Datierung herangezogen und lassen sich zur Eingruppierung verschiedener Klimazustände in der Vergangenheit nutzen. Die MIS werden rückwärts nummeriert (also größere Zahl = älter) und ungerade Zahlen stehen für Warmzeiten, gerade für Kaltzeiten.) 3 (ca. 57 to 27 kaka BP Mit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr.) is, compared to the recent warm phase, the Holocene, characterised by larger climate oscillations. These are detectable in δ18O records from Greenland ice cores and other climate archives in Europe, such as pollen or tree ring records. Unfortunately, little direct proxyProxy Umwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. evidence is available from central Europe, and the climatic and environmental conditions during MIS 3 remains largely enigmatic. Speleothem records from central Europe during MIS 3 are limited due to cold climate conditions and mainly restricted to the warmer southern or alpine regions, where meltwater enabled speleothem growth.
Preliminary 230Th/UU/Th-Datierung Die U/Th-Datierung ist eine sehr präzise radiometrische Altersbestimmung auf Basis der Uran-Thorium-Zerfallsreihe. Das Uran zerfällt mit bekannten Halbwertszeiten (245.500 Jahre) zum Tochterelement Thorium. Stalagmiten bauen bei ihrem Wachstum (fast) nur das wasserlösliche Uran ein, während das schlecht bewegliche Thorium zum größten Teil im Boden und Epikarst über der Höhle verbleibt. Das kann man nutzen, um die Zeit zu berechnen, die seit der Ausfällung der untersuchten Karbonatprobe vergangen ist. Moderne massenspektrometrische Verfahren erlauben Altersbestimmungen mit der U/Th-Methode bis zu 700.000 Jahren vor Heute.-dating of further speleothems from Bleßberg Cave (Germany) revealed two flowstones, which grew during MIS 3 and the Late Glacial. Therefore, these flowstones are the most northern continental growth of speleothems during MIS 3 in central Europe.
The main objective of this project is to construct a precisely dated multi-proxy climate record for MIS 3 and the Late Glacial based on the flowstones from Bleßberg Cave. This will provide the unique opportunity to obtain precisely dated information on terrestrial climate variability during selected phases of the last glacial period, which is currently not available for Central Europe based on speleothems. With the combination of several different proxiesProxy Umwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet., such as stable isotopes and trace elements, the results from a cave monitoring program, the analysis of the δD and δ18O values of inclusions of fossil water, and isotope-enabled climate modelling, we will be able to obtain detailed insights into environmental conditions in central Europe during MIS 3 and the Late Glacial.
Potsdam Institute for Climate Impact Research (PIK) – Group Development of advanced time series analysis techniques
The Potsdam Institute is a non-university research institute primarily concerned with questions about the causes and effects of climate change and with developing policy options to mitigate climate risks. It was founded in 1992 and is a member of the Leibniz Association.
The group “Development of advanced time series analysis techniques” of the department “Complex Systems” is involved in the research at Bleßberg Cave. Here, together with the partners, the age models for the stalagmites are calculated and complex statistical evaluations of the palaeoclimate data are carried out.
Contact
Web site
Publications
Isothermal thermoluminescence dating of speleothem growth – A case study from Bleßberg cave 2, Journal Article
In: Quaternary Geochronology, vol. 85, pp. 101628, 2024.
Poster, 2023, (Summer School on Speleothem Sciences 2023, Sao Paulo).
Poster, 2022, (KR9 Konferenz in Innsbruck).
Bleßberghöhle – Schatzkammer für die Wissenschaft Presentation
15.06.2022, (VdHK-Symposium: Wissenschaft unter Tage – Höhlenforschung im Dialog, Truckenthal (Germany)).
Die Bleßberghöhle – ein Glücksfall für die Klimaforschung Book Section
In: Thüringer Höhlenverein, e. V. (Ed.): Nächster Halt: Bleßberghöhle, Suhl, 2022.
Recurrence based entropies Presentation
07.05.2019, (Fourth International Conference on Recent Advances in Nonlinear Mechanics, Łódz (Poland)).
Recurrence based entropies Proceedings Article
In: Geophysical Research Abstracts, pp. EGU2019-2817, 2019.
Holocene interaction of maritime and continental climate in Central Europe: New speleothem evidence from Central Germany Journal Article
In: Global and Planetary Change, vol. 176, pp. 144–161, 2019.
Tracing past shifts of the boundary between maritime and continental climate over Central Europe Proceedings Article
In: Geophysical Research Abstracts, pp. EGU2018-9046, 2018.
A multi-proxy reconstruction of Holocene climate change from Blessberg Cave, Germany Proceedings Article
In: Geophysical Research Abstracts, pp. EGU2016-14213, 2016.
Recurrence properties as signatures for abrupt climate change Proceedings Article
In: Geophysical Research Abstracts, pp. EGU2014-8893, 2014.
Leibniz Institute for Applied Geophysics Hannover (LIAG) – Section 3: Geochronology
The LIAG is a non-university research institute in Hanover, which is concerned with the exploration of the usable subsurface as well as the development of geophysical measurement and evaluation methods. The institute looks back on more than 50 years of experience in geophysical research.
The section Geochronology is specialised in Quaternary geochronology using luminescence and electron spin resonance (ESRElektronenspinresonanz-Datierung Eine physikalische Datierungsmethode, die darauf beruht, daß die Menge magnetischer Anomalien im Probenmaterial proportional zur Lagerungszeit im Sediment ist.) methods. For Blessberg Cave the group is testing thermoluminescence (TL) dating of speleothems, which has a potential to date calcite up to ~2 million years. It is also planned to contribute in dating cave sediments.
Contact
Web Site
Publications
Isothermal thermoluminescence dating of speleothem growth – A case study from Bleßberg cave 2, Journal Article
In: Quaternary Geochronology, vol. 85, pp. 101628, 2024.
Isothermal thermoluminescence (ITL) dating of a speleothem from Bleßberg Cave Presentation
29.06.2023, (17th International Luminescence and Electron Spin Resonance Dating conference (LED2023), Copenhagen (Denmark)).
Insights in Bleßberg cave: Speleothem chronology and geochemical research Proceedings Article
In: 75. Jahrestagung der Deutsche Geophysikalische Gesellschaft in Hannover, 2015.
Novel methods for studying palaeoclimate dynamics
Recurrence based entropies Presentation
07.05.2019, (Fourth International Conference on Recent Advances in Nonlinear Mechanics, Łódz (Poland)).
Recurrence based entropies Proceedings Article
In: Geophysical Research Abstracts, pp. EGU2019-2817, 2019.
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
Poster, 2023, (Summer School on Speleothem Sciences 2023, Sao Paulo).
Timing and progression of Dansgaard-Oeschger events in Central Europe based on three precisely dated speleothems from Bleßberg Cave, Germany Proceedings
Poster, 2023, (XXI INQUA Conference, Rome (Italy)).
Poster, 2022, (KR9 Konferenz in Innsbruck).
Bleßberghöhle – Schatzkammer für die Wissenschaft Presentation
15.06.2022, (VdHK-Symposium: Wissenschaft unter Tage – Höhlenforschung im Dialog, Truckenthal (Germany)).
Die Bleßberghöhle – ein Glücksfall für die Klimaforschung Book Section
In: Thüringer Höhlenverein, e. V. (Ed.): Nächster Halt: Bleßberghöhle, Suhl, 2022.
Recurrence properties as signatures for abrupt climate change Proceedings Article
In: Geophysical Research Abstracts, pp. EGU2014-8893, 2014.
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.
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.
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.
Climate Zone Shift in central Europe
Bleßberghöhle – Schatzkammer für die Wissenschaft Presentation
15.06.2022, (VdHK-Symposium: Wissenschaft unter Tage – Höhlenforschung im Dialog, Truckenthal (Germany)).
Die Bleßberghöhle – ein Glücksfall für die Klimaforschung Book Section
In: Thüringer Höhlenverein, e. V. (Ed.): Nächster Halt: Bleßberghöhle, Suhl, 2022.
Holocene interaction of maritime and continental climate in Central Europe: New speleothem evidence from Central Germany Journal Article
In: Global and Planetary Change, vol. 176, pp. 144–161, 2019.
A multi-proxy reconstruction of Holocene climate change from Blessberg Cave, Germany Proceedings Article
In: Geophysical Research Abstracts, pp. EGU2016-14213, 2016.
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.
The temporal changes in isotope ratios were compared with palaeoclimate data from the Bunker Cave in North Rhine-Westphalia and from Greenland.
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).