Data stewardship scholarship project

SISAL was awarded a Data Stewardship Scholarship in November 2021.

Data steward

We have identified and confirmed commitment from two researchers (Micah Wilhelm and Peter Tanos) to work on:
(1) new trace element database;
(2) stable isotope database update; and
(3) the app.

Goals

1. Synthesise speleothem data of multiple novel proxies, in addition to the more traditionally measured oxygen and carbon isotopic data currently available in the SISAL database. The novel proxies include trace element ratios of Sr/Ca, Mg/Ca, Ba/Ca, U/Ca, P/Ca, and Sr isotope ratios. 167 speleothem trace element records have been identified by the SISAL WG.

Sr/Ca, Mg/Ca and Ba/Ca are sensitive to aridity, when carbonate precipitates prior to reaching the speleothem (Prior Carbonate Precipitation; PCP), resulting in increased speleothem Sr/Ca, Mg/Ca and Ba/Ca due to preferential incorporation of Ca. During times of past aridity, the drip water can degas in the air pockets in the overlying karst, resulting in increased amounts of PCP.
The concentration of these elemental ratios in speleothems can be impacted by other processes such as water-rock residence time and multiple sources of the elements (e.g. dust and sea spray) and their importance will be evaluated (e.g., using carbon isotopes already available in the SISAL database).
P/Ca has been linked to soil humic material and is thought to provide information of vegetation changes above the cave.
This multi-proxy approach will also allow us to test non-isotope enabled climate models and improve our understanding of climate processes encoded by the different proxies.

2. Add valuable new speleothem isotope records to the existing SISAL database.
3. Create a simple, user friendly app to mine the database.

Repository

The SISAL database updates with the additional proxy data will be publicly available from the University Research Data Archives and from NOAA/NCEI Paleo as previous versions of the SISAL database. We provide the database in SQL and CSV format. The University Research Data Archives allow us to keep track of database versions in a way that other platforms do not.
The standardised Excel input datasheet will be made available as supplementary material to the first database-related paper and on Zenodo. The codes will be made available on Github or Zenodo.

Final products

DSS (Data Stewardship Scholarship) product 1 - Trace element database:
This database will be interoperable with, and linked to the SISALv2 database. It will contain ~ 167 trace element records. To enable direct comparison with the isotopic data in SISALv2, we will provide standardised down-sampled datasets where necessary, and store the original high-resolution data on a repository such as FigShare.
In addition, we will store scans of the sampled speleothem sections in FigShare as ‘speleothem core stewardship’.

DSS product 2 - Update to SISAL stable isotope database:
SISALv2 will be updated with ~40 records of stable isotope data, and additional carbon isotope data, that have been published after the last SISAL database update.

DSS product 3 - Ease of database access:
Currently the SISAL database is available as a sql flatfile. Feedback from the research community suggests that database usage would increase with a more easily accessible front-end. We will develop an online app written in Java. A supporting paper is planned, aimed for open access publication in a journal such as SoftwareX.

> Access the SISAL webApp here: https://geochem.hu/SISAL_webApp/
> Access the description paper which has been published in Quaternary Research here.
> Download the paper as a pdf here.

These database products will directly feed into the SISAL WG Phase 2 goals of:

(i) assessing how trace elements can strengthen climatic interpretations of speleothem isotopic data in addition to providing independent palaeoenvironmental information;
(ii) to explore the use of proxy-system and process-based modeling to explain changes in speleothem isotopic records through time; and
(iii) to reconstruct the regional climatic response to global forcing mechanisms indicated by speleothem oxygen isotopic records.