Neuigkeiten: Physik der Umweltarchive Neuigkeiten der Physik der Umweltarchive
Juli 2025
3. Expedition to ERDMANNS-CAVE 2025
For several years now, the PUA teams have been investigating the Erdmannshöhle cave in southern Germany. Once a year, Dr. Sophie Warken and Dr. Andrea Schröder-Ritzrau take a group of students on an excursion to the cave, but we usually go there to collect water samples, determine the carbon dioxide content, and read the temperature and humidity loggers. Occasionally, we are also able to sample stalagmites, always keeping geotope protection in mind. Now we were back on site with a group of students and a guest from Mexico. Prof. Fernanda Lases Hernandez is a cooperation partner from Mexico with whom we share the results of our climate research and carry out joint measurements on stalagmites. She is our cooperation partner in the very successful DFG-funded project on climate development during the Maya civilization.
Juni 2025
25. Radiocarbon Conference in Krakau, Poland - 30.06 to 04.07.2025
We presented our work at the 25th Radiocarbon Conference in Krakow. We displayed a poster by Marika Hiemisch and colleagues on 14C in tropical corals from Puerto Rico and gave a presentation on 14C in stalagmites from Yucatan. Both research results were very well received and sparked numerous exciting discussions. It was a very successful conference and a wonderful city that inspired reflection thanks to its vibrant student life (170,000 students). We are now eagerly awaiting the new radiocarbon calibration curve in 2026 and hope to be able to publish some of our findings in the conference special issue of the journal Radiocarbon.
New Publication
In a new publication by Yao Wu, Dana Hölkermann, Amrei Grund, Sophie Warken, and Norbert Frank, we present our first steps toward a better understanding of isotope signals in skeletal water from cold-water corals. The investigation of isotope signals in coral skeleton fluid water remains difficult because the amount of enclosed water is very small and analytical methods lead to high variability. Advances such as encapsulation in glass capillaries improve reproducibility, but current techniques do not yet fully capture the original δ¹⁸O and δ²H values in coral aragonite. A better understanding of the calcification process and possible exchange processes with seawater is needed to better interpret these isotope signatures. More information about the publication can be found at G3.
Sampling Fossil cold-water corals at Marum, Bremen
Kathikeyan Arul, Sahra Greve, and Nils Schorndorf traveled to Bremen to sample fossil cold-water corals from the marine sediments of the Challenger Deep. Our project to investigate the origins of the Middle Pleistocene climate change involves dating the corals and examining nearby sediments for continental weathering products. Karthikeyan, Sahra, and Nils were able to successfully obtain a very large number of well-preserved fossil corals from the International Ocean Discovery Program (IODP - Expedition 307, borehole U1316). We are now very excited to date the corals.
Mai 2025
PAGES conference Shanghai 2025
We participated in organizing a session on the role of intermediate waters in the climate system. With six excellent presentations and seven posters, the meeting was a great success. Overall, the PAGES conference was once again characterized by outstanding contributions and good organization. Dr. Antao Xu's poster on Nd isotopes in the North Atlantic since the Mid-Pleistocene Transition was also a great success.
Numerous promising discussions arose during the meeting on the role of intermediate waters. We are offering to discuss a proposal for a new PAGES working group to address the question of what scientific knowledge is needed to better understand the role of intermediate waters (in the thermocline) for the climate. We made the announcement at the conference and hope that interest in such a potential group will grow. If you are interested in participating in such a new project, please contact Lélia Matos: lmmatos@ualg.pt
April 2025
EGU in Vienna - Austria
Dr. Sophie Warken and Prof. Nobert Frank represented the research team at this year's EGU in Vienna. For years, Dr. Sophie Warken has been leading a research focus on reconstructing the climate history using cave sinter, which was once again very well attended this year and featured excellent presentations and posters. We were represented at the conference with several posters and are delighted with the response to our research work. An important part of the conference was certainly the opportunity to talk to colleagues and exchange new ideas. The picture shows Sophie Warken as convenor with the invitation to attend the cave sinter dinner in the evening – a traditional meeting for all cave explorers. Dr. Kira Homola gave an excellent presentation on the activity of methane seeps in the Pacific Ocean and promoted research results on the age determination of bacterial calcareous deposits. Many thanks also to all our former students who always make this conference such an eventful occasion.
Links
New Publication and Software for Thorium-Uranium Dating
We present our stand-alone data analysis application for dating with multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The Python-based algorithm is equipped with a graphical user interface (GUI) and comprises raw data treatment, corrections, age calculation, and error estimation. Our underlying measurement protocol employs a combination of Faraday cups (FCs) and secondary electron multipliers (SEMs), and the software allows for different detector layouts for the measurement of the least abundant isotopes 234U, 230Th, and 229Th. We demonstrate the relevance of adequate data outlier treatment and generally recommend using the median instead of the mean of calculated ratios. The performance of our evaluation software is demonstrated by a case study from a Puerto Rican stalagmite with growth phases from the modern era to 40 kyr old.
März 2025
KR10 in Cape Town - South Africa
We were successfully represented at the international Karst Record 10 conference with numerous research contributions from the research groups Environmental Archives Physics, Tropical Climate Variability, and Speleothems Research. Yao Wu presented the results of his doctoral thesis, and Dr. Sophie Warken presented her research findings on the Laacher See explosion and the expansion of the SISAL database. Dr. Nils Schorndorf reported on climate change at the end of the Maya culture, and we made a big impression with two innovative contributions on machine learning strategies in paleoclimate research by master's students (Celine Kolb and Stephanie Gutmayer).
