Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - QUEST (QUantitative paleoEnvironments from SpeleoThems)

Teaser

Speleothems (cave deposits, e.g. stalagmites) represent unique terrestrial archives that allow for accurately dated, high-resolution (often annual), continuous and long (many millennia) climate reconstructions. Such records are vital for understanding how climate varies and...

Summary

Speleothems (cave deposits, e.g. stalagmites) represent unique terrestrial archives that allow for accurately dated, high-resolution (often annual), continuous and long (many millennia) climate reconstructions. Such records are vital for understanding how climate varies and how our environments respond on seasonal to millennial timescales.
However, current speleothem studies can only make qualitative inferences about climate parameters – i.e. they can tell us the direction of change (warmer, drier, etc.) but not the amount of change (how warm? how dry?). Quantitative information is crucial to make speleothem-based data more useful to climate modellers and policy makers.

QUEST (QUantitative palaeoEnvironments from SpeleoThems) will develop new techniques for extracting quantitative information from speleothems and link field and laboratory experiments on water/mineral chemistry with innovative physical and numerical analyses on speleothems. The combination of these techniques, based on physical and chemical properties and statistical methods, will allow us to deliver quantitative reconstructions of two key parameters: hydrology and temperature.

We will test our methods using speleothems from Australasia, a region vulnerable to El Niño-Southern Oscillation (ENSO) variability. At present, there is a relative dearth of millennial-scale palaeoclimate data from this region.ENSO governs rainfall distribution across the Pacific, including New Zealand, and even affects weather pattern in North America and Europe. Deeper understanding of past ENSO changes (best in a quantitative sense) is vital to assess risks posed by near-future ENSO variations.

Our team members come from a variety of backgrounds including environmental chemistry, environmental mineral magnetism, and numerical data analysis. Each group within the team has already begun developing innovative methods for palaeoclimate reconstruction within their own subfield, but this project will be the first time these methods are combined and applied collectively to speleothems. Our combination of interdisciplinary expertise, state-of-the-art instrumentation, and novel techniques means that we are ideally placed to develop quantitative climate records from speleothems.

Work performed

RISE project 691037 “QUEST” began in March 2016 with the first meeting held at Cambridge, including Fox and Hartland from UOW, NZ. The aim at hands-on training in the laboratory at Cambridge was done over two consecutive days and follow-up experiments were planned in bilateral discussions amongst all beneficiaries and partners. This meeting served for internal knowledge transfer, to align the different goals of QUEST and to plan the initial laboratory and field experiments. In the following months multiple virtual training and discussion sessions were conducted (using Skype). Breitenbach took a post at Ruhr-University Bochum (RUB) from April 2016, which resulted in the amendment to include RUB into the QUEST consortium. RUB has decade-long expertise with carbonate geochemistry and petrography, constituting a great pool of information now available to QUEST.

In preparation for field-related sampling and experiments Breitenbach visited Waikato in October 2016. This secondment was of major importance as it included knowledge transfer (Breitenbach to Hartland, Fox and students and technical support team), fieldwork in Waitomo cave including a detailed survey of the study area and sampling sites, installation of monitoring equipment in various field sites inside the cave and at the surface. A meteorological station was established to record changes in important climatic parameters, including temperature, humidity, wind speed and precipitation. Inside the cave, existing drip loggers were downloaded and new equipment installed, drip- and stream water collected for stable isotope and element analyses, and various readings taken (e.g., temperature of cave air and water, humidity, drip interval etc.). The cave was surveyed for future sampling and for the field-based experiments. Furthermore, a soil profile was opened above the cave for soil analyses. The water samples were analysed by the QUEST team in Cambridge, which gives a first baseline on the stable isotope signature (d18O, d2H). Besides the field work, the autosampling device was tested and ways to improve it in the Waikato workshop were discussed and planned with experts from the Mechanical Engineering Department at Waikato. An advanced prototype is currently built in Waikato and will be tested in 2018. Breitenbach lectured and presented QUEST in the Department at Waikato. Archive work at Waikato resulted in identification of unique sample material, which is currently being incorporated into the QUEST sample collection. Parallel to the fieldwork activities, Breitenbach (RUB) and Marwan (PIK) were able to link and publish 6 scientific publications in high-ranked journals, which discuss topics directly related to QUEST.
During their secondments from Waikato to Mainz and to Cambridge, Hartland and Fox conducted first experiments (DGT and magnetics). Multiple speleothems supplied by UOW and RUB have been tested by Lascu (UoC) for their suitability for the QUEST project and for quantitative reconstructions of past environmental conditions, some of which suggest potential as high quality archives.

The QUEST project, and especially its field component, received a welcome amount of public interest and has been explained to non-experts via different channels. Hartland (UOW) appeared in the local TV and presented the climate study, while Fox (UOW) took responsibility as science commentator for Radio NZ. Breitenbach (RUB) presented the QUEST project to the German caving community at the annual assembly, and to the general public via a popular science article in the Speleo-Berlin Newsletter (http://www.speleo-berlin.de/en_aktuell.php). Breitenbach participated in the RUB GMG Science Day, which is a platform to convey the message and goals of QUEST to specialists and non-experts alike. Given the positive feedback from the participants and organizers, we decided to partake in this event also in future.
Many presentations have been submitted to the international scientific community at

Final results

For the first period, the impact of QUEST to the scientific community is already felt, and six publications result from collaborations between different beneficiaries already. The impact for both society and scientific communities will be felt mostly after the project is concluded.

The public takes a lively interest in QUEST, with newsletters in Germany and New Zealand, radio interviews and TV broadcasts linked to our work in New Zealand. A great interest in the monitoring and climate research is seen from the audience during public lectures. Most people are interested in the impact of climate change and if and how we can measure this change in caves.
We will participate in more public outreach events in order to inform society and to keep the interested community updated on our progress.

Website & more info

More info: http://quest.pik-potsdam.de.