Ewelina Bros / Labor für Ionenstrahlphysik, ETH Zürich, Switzerland / Faculty of Geology, Geophysics and Environmental Protection / University of Science and Technology in Krakow, Poland
Thanks to the support of the CH-QUAT I could participate in the European Geosciences Union General Assembly 2017 in Vienna, Austria. Attending this conference was a valuable experience since it gives a great choice of many interesting plenary and poster sessions and a possibility to meet scientists from all over the world. In the “Advances in Quaternary Geochronology” session I presented the poster entitled “10Be cosmogenic nuclide chronology of the latest Pleistocene glacial stages in the High Tatra Mountains”. It is a part of my PhD project which focuses on final deglaciation of the highest mountain massif in the Carpathian arc. The aim is to constrain the timing and geometry of glacier advances during the final stages of the last glaciation in the Tatra Mountains by using a combined approach of detailed geomorphological mapping, cosmogenic nuclide exposure dating and Schmidt hammer measurement. To reconstruct the chronology and extent of these stages of glaciation, the upper parts of the mountains are investigated, where two well-developed systems of moraines and relict rock glaciers are present. Both systems are enclosed in the glacial cirque but are significantly different in their geometry, reconstructed direction of glacier advance and landform freshness. The applied methods give insight into the glacial activity in the Tatra Mountains during the Lateglacial which is still a poorly understood part of the complete glacial chronology of the valley as well as the entire mountain range. The results will contribute to understanding the deglaciation of these mountains at the end of the Pleistocene.
I am very grateful for the support from the CH-QUAT which allowed me to attend one of the biggest geological conferences and present there part of my study and the first results of an ongoing work on the deglaciation history of the Tatra Mountains.
Dominik Amschwand / Master’s Thesis at the Department of Earth Science / ETH Zurich, Switzerland
10Be and 36Cl Surface Exposure Dating of an Active Rockglacier in the Val d’Err, Grison
Supervisors: PD Dr. Susan Ivy-Ochs, PD Dr. Marcel Frehner
Although surface exposure dating with cosmogenic nuclides is a well-established method to reconstruct the Quaternary history of landscapes, it has not yet been applied to active rockglaciers. The aim of this thesis is to move into the periglacial realm by determining an absolute surface exposure age pattern on a presently active rockglacier in the Val d’Err, Oberhalbstein Alps (Grisons). The rockglacier originates in a cirque below Piz Bleis Marscha at an altitude of 2700 m a.s.l and stretches down to 2400 m a.s.l, with the lower half being inactive. The variegated lithologies of the Err nappes (Err granites, dolomites and radiolarites among others) allows to trace back the boulders to their origin in the headwall. Furthermore, we can compare the exposure ages obtained from 10Be and 36Cl radionuclides, derived from the granite and dolomite boulders, respectively. Geomorphological mapping and analysis of digital elevation models puts the age distribution into a broader context within the landscape.
The second part of the thesis consists of numerical modelling, where we try to reconstruct the rockglacier development from the nucleation to its present state. To roughly constrain the present surficial creep velocity, a sequence of aerial images spanning the last 60 years is evaluated.
This work is expected to provide insights on the feasibility of surface exposure dating with cosmogenic nuclides on rockglaciers, as well as on their formation and movement.
The support of CH-QUAT allowed me to carry out a 4-day field campaign in early August 2017, where we took the samples, discussed the microrelief and mapped the morphology. I’d like to thank my field team, PD Dr. Susan Ivy-Ochs, PD Dr. Marcel Frehner, Olivia Kronig, Ueli Steinemann and Dr. Reto Grischott. Furthermore, I am grateful for the logistical support provided by Armando Janett, Carole Müller and Peter Kaiser, and the financial support by CH-QUAT.
Mischa Haas / Eawag - Swiss Federal Institute of Aquatic Science and Technology / Duebendorf, Switzerland
I am a PhD Student at the Eawag Aquatic Research Institute in Dübendorf. I am very thankful that CH-QUAT supported my participation at the PAGES 5th Open Science Meeting in Zaragoza, Spain, in May 2017. I could present 2 Posters and had countless discussions with scientists working on similar research questions. After a week of plenary sessions, talks and posters, I was also able to attend a Geoarchaeology field trip, where we visited ephemeral streams of the Huerva River (Central sector of the Ebro Basin).
In my project PALEOFARM (Paleolimnological tracers of Early Farming), I’m reconstructing the impact of early agriculture on soil degradation and lake systems. Lacustrine sediments represent sensitive and continuous archives of high resolution and are well suited for studying anthropogenic induced environmental disturbances. My study areas are Lake Murten in Western Switzerland as well as several smaller lakes in Southern Greenland (Vatnahverfi) and Russian Karelia (Lavijärvi).
My first Poster that I presented had the title “Of Pile dwellers, Roman and Medieval Farmers – Early human impact on Lake Murten, Switzerland” and the co-authors were Franziska Baumann, Anna Reusch, Michael Strasser, Timothy Ian Eglinton and Nathalie Dubois.
In this study we investigated the sedimentary record from Lake Murten (Swiss Foreland Basin), whose region witnessed several phases of human occupation starting already thousands of years ago during the Neolithic Period. We applied a multi proxy approach including several geophysical, geochemical and biological methods on a 10 m sediment core from the deepest part of the lake. Interestingly, our paleolimnological data show that human impact only started to be recorded in the sediments during Roman times. Although Pile dwellers occupied Lake Murten for almost 3000 years, the Romans were the first who left visible traces in the sedimentary record, the deposition of varves being the most obvious one.
My second Poster had the title “How politics shape agricultural landscapes: The plant wax record of Lake Lavijärvi, Russia Karelia”. My co-authors were Natalya Belkina, Dimitry Subetto and Nathalie Dubois. We investigating lacustrine sediments from Lake Lavijärvi (Russia Karelia) to reconstruct past soil loss and soil degradation in the catchment, with a focus on soil carbon dynamics.
The region of Sortavala in the Russian Republic of Karelia has witnessed severe changes in land-use in the last century. During World War II, intensive field cultivation with regular ploughing occurred in the catchment of Lake Lavijärvi, initiating soil erosion and consequently lake eutrophication. In the post-war period, the arable fields were mostly converted to pastures as the land was ceded to the Soviet Union by Finland. Shifts in pollen and diatom assemblages revealed that the lake became eutrophic in the 1920s-30s, with the mechanization of agriculture, and oligotrophic again following the relaxation of human pressure in the post-war-period. I presented preliminary results of the n-alkane and n-carboxylic acid homologue patterns in comparison with the grainsize distribution, magnetic susceptibility, concentration of detrital elements (i.e. Ti, Fe, Mn) as well as the CaCO3, total organic carbon (TOC), and total nitrogen (TN) content.
EAWAG - Sedimentology (Surf Dept.)
Benjamin Bellwald/ University of Bergen, Bergen, Norway / Volcanic Basin Petroleum Research, Oslo, Norway
Geological structures revealed by High-Resolution P-Cable 3D Seismic Data in the SW Barents Sea
High-resolution 3D seismic data have significantly increased our knowledge about petroleum reservoirs and submarine geohazards. However, little effort has been undertaken to evaluate the potential of such data for mapping subglacial landforms. The Barents Sea has been subjected to repeated Pleistocene glaciations, which intensively eroded the region, resulting in a generally thin (<100 m) Quaternary sediment cover. The Quaternary sediment packages of different P-Cable 3D seismic cubes in the SW Barents Sea are used to study subglacial expressions and the correlation with the subsurface geology. We compare different geophysical technologies commonly used by the offshore industry, and discuss benefits and limitations of data collected by multibeam echosounder, sub-bottom profiler, 2D/3D seismic and P-Cable 3D. We conclude that the mapped seabed morphologies are strongly dependent on the sub-bottom geology. Besides linking seabed expressions with the subsurface geology, P-Cable 3D includes information about seismic amplitudes. Combining different seismic volume attributes allow to improve the visualization and characterization of subglacial features. Glacial surfaces, such as the contemporary seabed and paleo-seabeds, are imaged in multibeam-echosounder quality using P-Cable 3D seismic data. Surfaces of prominent intra-glacial reflections reveal moraines, mass transport deposits and soft beds, which cannot be identified in conventional seismic data. Therefore high-resolution seismic data are beneficial in identifying and analyzing small-scale glacial structures and their expression in the underlying strata in great detail, contributing to the understanding of processes involved in paleo-ice stream dynamics.
I am very grateful for the support from the Swiss Society for Quaternary Research (CH-QUAT), which allowed me to present my latest results at EGU Vienna in the session “Subglacial landform genesis and (palaeo) glaciological significance”. The discussions link to my poster presentation have been very beneficial and inspiring for my future research.
Elena Bruni/ Master’s Thesis at the Department of Earth Science at ETH Zürich
Supervisors: Dr. Sean Gallen, Richard Ott
The aim of my Master’s thesis is to understand the timing and depositional regime of the Kladou River fan sequence in Domata, southwestern Crete. It has been proposed that deposition occurred in the Late Pleistocene and linked to climate change, but several researchers have questioned the methods used to obtain this age and the proposed fan genesis model. My hypothesis is that the depositional age of the fan is Holocene and the result of catastrophic events (e.g. large-scale mass-wasting), which will be tested by a detailed stratigraphic study of the sequence and by performing geochronology on the deposits. Methods involve stratigraphic logging, soil characterizations, Radiocarbon dating and OSL dating. Also, a drone has been used to scan the fan sequence and obtain a detailed surface model of the deposit. The information obtained by working on the fan sequence is expected to lead to a better understanding of extreme erosion events on geomorphology, sediment transport and deposition processes in coastal streams in the Mediterranean. Additionally, the results are used to support research on uplift rates in Crete.
The support of CH- QUAT allowed me to carry out research in Crete in June 2017 with the appropriate material and tools. I am very grateful for the support!
Jonas von Wartburg / Master’s Thesis at the Department of Earth Science / ETH Zurich, Switzerland
Constraining the age and source area of the Molveno landslide deposits in the Brenta Group, Trentino Dolomites
Supervisors: PD Dr. Susan Ivy-Ochs, Dr. Kerry Leith and Prof. Dr. Silvana Martin
The aim of this master project is to constrain the age and source area of the Molveno rock avalanche(s) and to determine if one or several events were necessary to form the present deposits. The project includes two weeks of fieldwork for geomorphological mapping, structural analysis and rock sampling. Afterwards surface exposure dating will be performed in the Ion Beam laboratory at ETH to constrain the age of the deposits. Runout modelling, using DAN3D or DAN flex, on a reconstructed landscape will be used to test the plausibility of hypothetical source areas and volumes. Structural analysis will help to reconstruct the landscape and to develop an understanding of the controlling mechanism. So far only radiocarbon dates from logs in lake Molveno exist, which do not necessarily represent the age of the landslide. Over source areas of the landslide, heretofore several contradictory opinions have been published. Until now, no runout simulations have been performed to constrain the different hypothesis.
The support of CHQUAT allowed to carry out intense field work around Lake Molveno during one week in July 2017. Several days in September and November 2017 will follow. Fieldwork includes mapping of the morphology, sampling boulders in the deposition area and source area for surface exposure dating and thin-section analysis, taking structural measurements and taking sketches and photographs of morphological features and outcrops.
Jonas von Wartburg
Loren Eggenschwiler/Master thesis at ETH Zurich and at the Swiss Federal Institute for Forest, Snow and Landscape Research WSL/ Switzerland
In April 2017, I attended my first EGU conference with the support of CH-QUAT. Through their support I was able to attend and present my poster at this international conference held in Vienna, Austria each year. This year EGU had 107 countries in attendance. This included 4,849 oral presentations, 11,312 posters, 1, 238 PICO presentations and 14,496 scientists (www.EGU2017.eu). I presented a poster on “Radiocarbon dating and Dendrochronology for Stratigraphic Units near Tebano, Senio Northern Apennines – Times frame of Climatic Fluctuation at the onset of the Younger Dryas”. I presented the motivation and work done during my thesis work and as well as results that will be used to publish a paper in the future.
Abstract: The presence of Pinus [sylvestris] provides an insight into dramatic events due to climatic changes. Several major and minor climatic fluctuations have had a strong impact on terrestrial and marine environments since the last glacial period to present day (Ravazzi et al. 2006). This study aims to describe the response of a fluvial environment through the use of dendrochronology and stratigraphy. Here, we intend to get a better understanding of how these climatic fluctuations affect the behavior of the Senio River (Lotter et al. 1992). In Tebano, Italy, several Pinus sylvestris subfossil trunks were discovered during excavation for an irrigation pool. Subfossil samples were collected to analyze the climate during the Younger Dryas (11,000 years BP) in detail. Charcoal samples from the Bubano clay quarry extend our research to further to 35,500 cal. years BP. The combination of dendrochronology along with stratigraphy allowed us to examine the climate at a detailed local and apply it to a broader spectrum. Tree-ring measurements and cross dating provided a better understanding and verification of extreme events that occurred during the lifespans of the trees. The use of stable isotopes indicates the extreme conditions that occurred. Radiocarbon dating validates the age of the samples and what geological period they come from. Along with stratigraphy, we were able to compile depth data to create a sediment curve. Using various methods throughout this study, we discovered the climatic situation of Pinus 11,000 years BP and are able to compare them with samples from today. These present day samples mark two of the southernmost extents of the Pinus population. We were then able to comprehend the magnitude of sediment supply and precipitation. Through this collection of methods and data, we are able to understand the influence of climate change in the past and the potential changes of the future.
REFERENCES Lotter, A. F.; Eicher, U.; Siegenthaler, U.; Birks, H. J. B. (1992): Late-glacial climatic oscillations as recorded in Swiss lake sediments. In Journal of Quaternary Science 7. DOI: 10.1002/jqs.3390070302. Ravazzi, Cesare; Donegana, Marta; Vescovi, Elisa; Arpenti, Enrico; Caccianiga, Marco; Kaltenrieder, Petra et al. (2006): A new Late-glacial site with Picea abies in the northern Apennine foothills. An exception to the model of glacial refugia of trees. In Veget Hist Archaeobot 15 (4), pp. 357–371. DOI: 10.1007/s00334-006-0055-9.
Outlook: It was a very exciting opportunity to see work done from all corners of the world. It was additionally exciting to see colleagues and friends present their work via posters and presentations as well as meeting many new people with similar interests. It was inspiring to see the various projects and potential work that can be done. EGU was a wonderful and stimulating experience.
Eidg. Forschungsanstalt WSL
Katarzyna Marcisz / Paleoecology Section, Institute of Plant Sciences / University of Bern, Switzerland
CH-QUAT supported my participation in the 5th Open Science Meeting of PAGES, Past Global Changes in Zaragoza (Spain) from 9-13 May 2017. PAGES OSMs are one of the biggest palaeoecological conferences worldwide. In Zaragoza, more than 900 scientists from all over the world took part in the meeting.
At the conference I presented my work entitled “Tiny but powerful – the use of functional traits of testate amoebae as disturbance indicators in palaeoecological studies of peatlands” co-authored by Daniele Colombaroli, Vincent E. J. Jassey, Willy Tinner, Piotr Kołaczek, Mariusz Gałka, Monika Karpińska-Kołaczek, Michał Słowiński and Mariusz Lamentowicz.
Peat cores retrieved from peatlands are commonly used for various palaeoecological investigations, i.e. to reconstruct past vegetation changes or human impact. Additionally, analysis of testate amoebae is often used because those microorganisms provide information about past hydrological changes – using testate amoeba data transfer functions can be applied for quantitative reconstruction of past water table depth. Such analysis focus on changes in testate amoeba species composition over time.
In our study, we focused on morphological traits (such as body size, aperture size and position) and physiological traits (such as metabolic status or hydrological preferences) of testate amoeba species to find out if any of those traits could be regarded as indicators of disturbances. We analysed traits of testate amoebae from two peatlands in Poland that were disturbed in the past – one of them was disturbed by fire and the other one by substantial peat extraction. We found out that two of analysed traits (mixotrophy and plagiostomic apertures) were connected with disturbances. We therefore think that species traits could be regarded as indicators and could be used in palaeoecological studies to support conventional analysis of testate amoeba communities.
Marcisz K., Colombaroli D., Jassey V.E.J., Tinner W., Kołaczek P., Gałka M., Karpińska-Kołaczek M., Słowiński M., Lamentowicz M., 2016. A novel testate amoebae trait-based approach to infer environmental disturbance in Sphagnum peatlands. Scientific Reports 6, 33907.
Dr. Katarzyna Marcisz
Paleoecology Section, Institute of Plant Sciences, University of Bern
Altenbergrain 21, 3013 Bern, Switzerland
Marie-Eve Monchamp /PhD thesis at ETH Zurich and at the Department of Aquatic Ecology, Eawag/ Switzerland
I am a PhD student at Eawag in the field of aquatic ecology and I am interested in the impact of humans on the biodiversity and distribution of cyanobacteria in lakes. The main aim of my PhD thesis is to reconstruct the past dynamics of cyanobacterial diversity and relate the changes to human-induced alteration in the local (e.g. nutrient availability) and regional (e.g. climate warming) environmental conditions.
Thesis title: Sedimentary DNA reveals centuries of hidden diversity in lake cyanobacterial communities
Supervisors: PD Dr. Piet Spaak, and Dr. Francesco Pomati
CH-QUAT supported my participation to the PAGES 5th Open Science Meeting in Zaragoza, Spain, May 2017 where I presented my work entitled "Impact of eutrophication and climate change on cyanobacterial diversity across European pre-alpine lakes over 150 years". (Authors: Marie-Eve Monchamp, Piet Spaak, Isabelle Domaizon, Nathalie Dubois, Francesco Pomati)
Human activities have impacted terrestrial and aquatic ecosystems over the last few centuries. Climate change and eutrophication have had profound effects on lakes, which stimulated phytoplankton growth and increased the frequency and strength of harmful cyanobacterial blooms. The mitigation of phosphorus loading has contributed to the return of some lakes to a lower trophic state. However, cyanobacteria often continue to dominate the phytoplankton community, impairing ecosystem functioning and water quality. Due to the scarcity of long-term lake data (both biotic and abiotic), the state of past ecosystems and the phytoplankton response to warming and rapid changes in local conditions remain poorly understood. With the aim of bridging this gap, we investigated the dynamics of cyanobacterial communities across 10 European pre-alpine lakes over the last 150 years using sedimentary records. More specifically, we used high throughput amplicon sequencing to explore temporal changes in the regional distribution and the phylogenetic diversity of cyanobacteria.