Meet QUEST at EGU 2018

7. March 2018EGU, Meeting, News, Outreach

With the EGU General Assembly coming up next month, we have rounded up the first-author presentations from the people involved in QUEST. Most of the action takes place during Thursday and Friday (barring David Hodell’s presentation on Tuesday) and in Hall X5 and Room F2. Be sure to note this down in your calendar for the EGU week!

The topics are many, interesting, and diverse — they are sure to spark off interesting discussions and debate. Share this post with your colleagues and spread the word!

CL 1.11

Novel and quantitative methods for continental palaeoenvironmental reconstruction.

Orals: Thu, 12 Apr, 10:30–12:00 / Room 0.14
Posters: Attendance Thu, 12 Apr, 17:30–19:00 / Hall X5

ID	TITLE & QUEST AUTHORS	TYPE & LOCATION
13780	Towards a quantitative proxy of cave dripwater hydrology Adam Hartland, Beth Fox, Sebastian Breitenbach	Poster, X5.251
12744	Local and distant Pacific climate signals in cave hydrochemistry: Waipuna cave, New Zealand Cinthya Nava, Adam Hartland, Bethany Fox, Sebastian Breitenbach	Poster, X5.250
9793	35,000 years of hydrological variability in northern New Zealand from speleothem magnetism Bethany Fox, Ioan Lascu, Sebastian Breitenbach, Adam Hartland	Poster, X5.246
9046	Tracing past shifts of the boundary between maritime and continental climate over Central Europe Sebastian Breitenbach, Norbert Marwan	Poster, X5.245
15956	Is this an event? - Detecting abrupt changes in palaeoclimate records Bedartha Goswami, Sebastian Breitenbach, Norbert Marwan	Poster, X5.244

NP 2.4

New model and data-based approaches to study climate behavior

Orals: Fri, 13 Apr, 08:30–12:00 / Room M1
Posters: Attendance Fri, 13 Apr, 13:30–15:00 / Hall X4

ID	TITLE & QUEST AUTHORS	TYPE & LOCATION
6190	Detecting abrupt transitions during the Late Quaternary in southern Ethiopia using Recurrence Quantification Analyses Hauke Krämer, Norbert Marwan	Oral, Room M1
15457	Identifying sudden dynamical shifts in time series with uncertainties Bedartha Goswami, Sebastian Breitenbach, Norbert Marwan	Poster, X4.277

CL 1.17

The speleothem archive: understanding processes and interpreting Quaternary climate change

Orals: Thu, 12 Apr, 13:30–17:00 / Room 0.14
Posters: Attendance Thu, 12 Apr, 17:30–19:00 / Hall X5

ID	TITLE & QUEST AUTHORS	TYPE & LOCATION
16111	Application of lignin analysis to flowstone, stalagmite and drip water samples – potentials of a new proxy Inken Heidke, Denis Scholz, Thorsten Hoffmann	Poster, X5.286

CL1.06/GM8.12/HS1.19

Tackling past hydrological cycles – from local and regional to global scales (co-organized)

Orals: Fri, 13 Apr, 08:30–10:00 / Room F2
Posters: Attendance Fri, 13 Apr, 17:30–19:00 / Hall X5

ID	TITLE & QUEST AUTHORS	TYPE & LOCATION
19020	Last Glacial Period hydrology of Lake Peten Itza (Guatemala) constrained with triple oxygen and hydrogen isotopes Thomas Bauska, David Hodell	Oral,Room F2

CL 1.31

Climate response to orbital forcing (including Milutin Milankovic Medal Lecture)

Orals: Tue, 10 Apr, 13:30–17:00 / Room F2
Posters: Attendance Tue, 10 Apr, 17:30–19:00 / Hall X5

ID	TITLE & QUEST AUTHORS	TYPE & LOCATION
3858	Integrating suborbital climate variability with classical Milanković theory David Hodell	Oral, Room F2

During her scientific stay in New Zealand, Cinthya published her experiences in her “The Cave Journey” blog: https://thecavejourney.wordpress.com/

Novel numerical method to analyse multivariate proxy records

25. January 2018News, Paper

Members of the QUEST team have published a new approach for analysing multivariate proxy records with recurrence networks. The idea is to first consider each proxy separately as a recurrence network, then combine them as layers of a multiplex network, and derive a similarity measure from this resulting multiplex recurrence network. This approach can be used to reveal periods of converging dynamics or very disperse variability, as demonstrated on an example of palaeo vegetation development during the last 16 ka in East Asia.

Multiplex recurrence network

Further reading:
https://journals.aps.org/pre/abstract/10.1103/PhysRevE.97.012312

New study on short time series published

8. January 2018Paper

The “inner composition alignment approach” (IOTA) has been suggested in the past for detecting interdependencies between short time series. QUEST members have now published a new study with a modification of this approach (called mIOTA). The new extension overcomes the drawbacks that IOTA is unable to distinguish between positive and negative correlations, and that the null distribution for IOTA is biased towards higher values. Although the new method cannot detect the direction of the interdependencies (unlike IOTA), it outperforms standard tools for detecting interdependencies (Pearson correlation, Spearman correlation, Kendall’s τ). The method is used to derive econo-climatic networks of interdependencies between economic indicators and climatic variability for Sub-Saharan Africa and South Asia including India.

Further reading:
http://www.ias.ac.in/describe/article/conf/001/01/0051-0060

Important step forward to recurrence analysis of data with uncertainties

4. January 2018Paper

In a new publication we propose a novel approach for analysing data with uncertainties, which is typical, e.g., in palaeoclimate observations. A time series of single values is replaced by a time series of probabilities; the binary matrix representation of recurrences is then replaced by a matrix of probability values, which represent that a recurrence at a certain time appears. This approach is the base for a novel transition test, applying concepts from recurrence and complex network analysis. We demonstrate the potentials on examples from present-day climate (ENSO), palaeoclimate (Indian summer monsoon), and stock markets.

Time series of probability distributions of proxy values, allowing for uncertainty analysis.

Open access: https://www.nature.com/articles/s41467-017-02456-6

EGU 2018 Session SC1.10/CL6.06/GM12.4/SSP2.20

19. December 2017EGU, Meeting, News

We´d like to invite everybody interested in innovative and quantitative methods for continental palaeoenvironmental reconstructions to attend our short course (details below) at the General Assembly of the European Geosciences Union, 8-13 April 2018.

SC1.10/CL6.06/GM12.4/SSP2.20
Age Models and geochronology: An introductory course to different age-depth modelling approaches (co-organized)

Convener: Carole Nehme
Co-Conveners: Sebastian F.M. Breitenbach , Michael Dietze , Annegret Larsen

Abstract:
In an era of science that uses numerical models to better understand physical processes occurring on Earth, there is an increasing demand for robust empirical datasets to constrain these simulations. Generating robust datasets, especially data sets that express stratigraphic positions of sedimentary deposits as ages, often involves the use of multiple, independent geochronological techniques (e.g. different kinds of radioisotopic dating, magneto-, bio-, cyclostratigraphy and sedimentologic relationships along the succesion). The integration of these different kinds of geochronological information often poses challenges.

Age-depth models are the ultimate result of the integration of different geochronological techniques, and range from linear interpolation to more complex Bayesian techniques. Invited speakers Christian Zeeden and David De Vleeschouwer will share their experience in several modelling concepts and their application in a range of paleoenvironmental and paleoclimatic records. The Short Course will provide an introduction to the field of (Bayesian) age-depth models and will highlight the assumptions, benefits and limitations of different model approaches. It will prepare the participants from CL, GM and SSP divisions for independent application of suitable age-depth models to their data.

We hope you will enjoy this short course.
Please feel free to contact us if you have any questions.
Hope to see you in Vienna and

Merry Christmas!
Seb, Carole, Michael and Annegret

Short course page at the EGU website:
http://meetingorganizer.copernicus.org/EGU2018/session/28970

EGU 2018 Session CL1.11

19. December 2017EGU, Meeting, News

We´d like to invite everybody interested in innovative and quantitative methods for continental palaeoenvironmental reconstructions to submit abstracts for our session (details below) at the General Assembly of the European Geosciences Union, 8-13 April 2018.

CL1.11 
Novel and quantitative methods for continental palaeoenvironmental reconstruction.

Convener: Jessica Oster 
Co-Conveners: Sebastian F.M. Breitenbach , Bethany Fox , Adam Hartland

Abstract:
In recent decades, quantitative methods have become increasingly important in the field of palaeoenvironmental and palaeoclimatic reconstruction, due to the need for comparison between different records and to provide boundary conditions for computational modelling. Continental environmental archives (e.g. speleothems, lake sediments, ice, or land snails) are often highly temporally resolved (subdecadal to seasonal) and may provide more direct information about atmospheric processes than marine archives. The wide variety of archive types available on land also allows for intercomparison and ground-truthing of results from different techniques and different proxies, and multi-proxy reconstructions from the same archive can disentangle local and supra-regional environmental conditions.

This session aims to highlight recent advances in the use of innovative and quantitative proxies to reconstruct past environmental change on land. We welcome studies of any continental archive, including but not limited to carbonates (caves, paleosols, snails), sediments (lakes, rivers, alluvial fans), ice, and biological proxies (tree rings, fossil assemblages, plant biomarkers). We particularly encourage studies involving the calibration of physical and chemical proxies that incorporate modern transfer functions, forward modeling and/or geochemical modeling to predict proxy signals, and quantitative estimates of past temperature and precipitation amounts. We also welcome reconstructions of temperature and hydrologic variability over large spatial scales, including paleoclimate data assimilation studies. This session will provide a forum for discussing recent innovations and future directions in the development of terrestrial palaeoenvironmental proxies on seasonal to multi-millennial timescales.

We hope you will enjoy this session.
Please feel free to contact us if you have any questions.
Hope to see you in Vienna and

Merry Christmas!
Seb, Beth, Jessica and Adam

Session page at the EGU website:
http://meetingorganizer.copernicus.org/EGU2018/session/28897

A very active southern hemisphere team!

1. December 2017Fieldwork, News

At the end of November, Beth and Cinthya had a very fruitful time while participating at the annual conference 2017 of the Geoscience Society of New Zealand, presenting preliminary findings of speleothem magnetism and cave monitoring in and around Waipuna cave.

In the meantime, Adam, Inken, and Cinthya had an intense work in the field visiting Waipuna cave to carry out the SH summer monitoring collecting water samples from the drip points and taking measurements of the physicochemical properties. Additionally, the team installed the first sampling device for the analysis of cave organic aerosols, with the objective of characterizing the cave´s response to external conditions. After, 5 field trips and a lot of hours of intense work underground, the team returned home tired but very happy, with many samples and a bunch of data ready to be analyzed at the Waikato University, University of St Andrews, and Johannes Gutenberg-Universität laboratories. Now, all of us are looking forward to the next adventure.

Sampling in the Waipuna cave

Workshop on palaeoclimate time series analysis and statistics in Potsdam

7. November 2017Meeting, News, Outreach

Last week, representatives of all QUEST collaborators met on the Telegrafenberg in Potsdam for the QUEST Workshop on palaeoclimate time series analysis and statistics to disseminate our results, first among ourselves, and then to a public audience. We would like to thank all participants for their contributions and lively discussions.

The workshop was very nicely organized by Bedartha and Norbert. Beth came all the way from New Zealand, while David came from Great Britain, Inken from Mainz, and Seb and Cinthya from Bochum. We started with a short summary of ongoing work and activities in the different laboratories. An important point raised and discussed were the planned secondments (Cinthya and Inken had aleady packed for their secondments to Waikato!) and under which conditions Thomas can actively participate to QUEST. We then got quick updates from the different laboratories, all make good progress with respect to quantification of proxy data. A cosy workshop dinner in Old Town Potsdam facilitated more discussions of ideas and thoughts.

On Thursday and Friday we had several lectures and hand-on sessions, open to the public. Colleagues from as far as Australia learned about agemodeling, recurrence analysis and other innovative statistical tools developed at PIK Potsdam. Hands-on sessions gave the opportunity to discuss the complexities of unpublished data and the subtilities hidden inside the obvious.

The workshop also served as a platform to strike new collaborations and to exchange ideas how to extract a wealth of information from multi-proxy data.

The next workshop will take us to the Antipodes.

Public outreach at the 20th anniversary of the Speleo Club Berlin

24. September 2017News, Outreach

The Speleo Club Berlin is a small caving club of cavers from Germany’s capital and surrounding region. At the 20th anniversary of this club in the assembly hall of the “Radfahrer-Kirche” in Kienitz at September 23rd 2017, Norbert gave a public talk on several scientific aspects of cave research, including speleothem based palaeoclimate studies as performed within QUEST. The audience, consisting not only of speleologists but also of the curious public, has been very interested and enquiring.

Norbert presenting at the 20th anniversary of the Speleo Club Berlin.