About - Paleointensity.org

Team

Annemarieke Béguin ¹
Greig A. Paterson ²
Andrew J. Biggin ²
Lennart V. de Groot ¹
Simon Lloyd ²
Alexander W. Tully ²
Joren Paridaens ³

¹

²

¹ Paleomagnetic Laboratory Fort Hoofddijk, Department of Earth Sciences, Utrecht University, Netherlands
² Geomagnetism Laboratory, Oliver Lodge Labs, School of Environmental Sciences, University of Liverpool, United Kingdom
³ Coöperatie 9de online

Source code

Thellier selection criteria statistics are based on the Standard Paleointensity Definitions v1.1 (Paterson et al., 2014). The calculations for the Multispecimen protocol are based on the VBA-based software tool presented by Monster et al., (2015).

The Python source code used for all calculations are publicly available on GitHub and the source code for version 1.0.0 can be accessed through the Zenodo repository

Demo data

The demo data for Thermal Thellier consist of a sub-set of the calibration data set presented along the SPD.
The Microwave Thellier demo data shows two specimens from the East Eifel, Germany (Monster et al., 2018).
For pseudo-Thellier the demo data consists of four sediment specimens from the Taranto Gulf in the Mediterranean, providing relative intensity values (Béguin et al., 2019).
For the Multispecimen protocol the demo data comprises a sub-set of the test data for the VBA-based MSP-Tool (Monster et al., 2015) and two sites from Hawaii (de Groot et al., 2013).

Input formats

The different analyzing methods support different input formats. Below an explanation of the currently available input formats. Requests for a specific input format can be sent to: paleointensity@uu.nl

Microwave Thellier MagIC format (v3.0) example | definition Liverpool format (csv) example | definition

pseudo-Thellier MagIC format (v3.0) example | definition Utrecht format (AF) example | definition pTh format example | definition Modified PmagPy format example | definition

Shaw method Liverpool PTSD RAPID .rmg RAPID .sam RAPID .xls

Multispecimen protocol MagIC format (v3.0) example | definition JR6 output files example | definition MSP generic format example | definition

References

Béguin, A., Paterson, G. A., Biggin, A. J., & de Groot, L. V. ( 2020). Paleointensity org: an online, open source, application for the interpretation of paleointensity data. Geochemistry, Geophysics, Geosystems, 21, e2019GC008791.
https://doi.org/10.1029/2019GC008791 Béguin, A., Paterson, G. A., Biggin, A. J., & de Groot, L. V. ( 2020). Paleointensity org: an online, open source, application for the interpretation of paleointensity data - source codes (Version V1.0.0). Geochemistry, Geophysics, Geosystems. Zenodo.
http://doi.org/10.5281/zenodo.3744224 de Groot, L. V, Biggin, A. J., Dekkers, M. J., Langereis, C. G., & Herrero-Bervera, E. (2013). Rapid regional perturbations to the recent global geomagnetic decay revealed by a new Hawaiian record. Nature Communications, 4, 1–7.
http://dx.doi.org/10.1038/ncomms3727 Leonhardt, R., Heunemann, C., & Krása, D. (2004). Analyzing absolute paleointensity determinations: Acceptance criteria and the software ThellierTool4.0. Geochemistry, Geophysics, Geosystems, 5(12)
http://doi.wiley.com/10.1029/2004GC000807 Paterson, G. A., Tauxe, L., Biggin, A. J., Shaar, R., & Jonestrask, L. C. (2014). On improving the selection of Thellier-type paleointensity data. Geochemistry, Geophysics, Geosystems, 15(4), 1180–1192.
https://doi.org/10.1002/2013GC005135 Shaar, R., & Tauxe, L. (2013). Thellier GUI: An integrated tool for analyzing paleointensity data from Thellier-type experiments. Geochemistry, Geophysics, Geosystems, 14(3), 677–692.
http://doi.wiley.com/10.1002/ggge.20062 Monster, M. W. L., Langemeijer, J., Wiarda, L. R., Dekkers, M. J., Biggin, A. J., Hurst, E. A., & Groot, L. V. de. (2018). Full-vector geomagnetic field records from the East Eifel, Germany. Physics of the Earth and Planetary Interiors, 274, 148–157.
https://doi.org/10.1016/j.pepi.2017.11.009 Monster, M. W. L., de Groot, L. V, & Dekkers, M. J. (2015). MSP-Tool: A VBA-Based Software Tool for the Analysis of Multispecimen Paleointensity Data. Frontiers in Earth Science, 3, 3–9.
https://doi.org/10.3389/feart.2015.00086 Tully, A. W., & Paterson, G. A. (2025). Another simple test for the presence of multidomain behavior during paleointensity experiments. Journal of Geophysical Research: Solid Earth, 130, e2025JB031608.
https://doi.org/10.1029/2025JB031608

Changelog

V1.1.3 18/08/2026
Fixed - The δt* tail check now uses the angle between the NRM and the applied field direction in radians instead of degrees. Previously the correction term was skipped for almost all specimens.

V1.1.2 09/06/2026
Fixed - The Ziggie criterion no longer crashes on certain Thermal Thellier data points.
Fixed - Auto-interpret no longer crashes when pTRM checks fall outside the selected temperature range.
Fixed - Removing a site or specimen in the Manage section no longer throws a runtime error.

V1.1.1 15/05/2026
Added - The 'Ziggie' selection criterion (Tully and Paterson, 2025).
Added - The 'RMS' selection criterion, the root mean square error of the Arai plot fits.
Fixed - Exports of .csv files now always use the correct file extension, also when a specimin name contains a .
Fixed - The value of the pseudo-Thellier criterions b_AA and b_DD can now be set.

V1.1.0 25/10/2024
Released V1.1.beta as version 1.1.0 🎉

V1.1.beta2 30/08/2024
Added - Added the Shaw method, including input formats and calculation engine.
Added - Automatic file format detection, where possible.
Added - The possibility to export plots to a high resolution .png or a .csv file.
Added - Plot customization.
Fixed - Font issues with the .svg export.

V1.1.beta1 07/02/2024
Fixed - When the anisotropy tensor cannot be calculated because of a lack of data, an error message is shown.
Fixed - In some cases data of a previous calculation was used when not present in the current specimen.
Fixed - Measurements without IZZI pair where not correctly ignored when calculating Tmin and Tmax.
Fixed - Steps with only anisotropy measurements will no longer be shown in the stepselector or as Tmin or Tmax.
Added - More robust validation of the calculation results, with appropriate error messages.
Added - Ability to zoom in graphs
Changed - Color and font styling

V1.0.1 23/12/2020
Fixed - Removing 'all interpretations' of a specimen would remove all interpretations of the sample.
Fixed - Hovering over MSP specimens did not trigger the highlight effect in the two graphs.
Added - 'Initializing' feedback for the first load of the Analyses page.
Added - An "Are you sure" dialog when removing all interpretations.
Added - The favicon.
Added - This changelog.

V1.0.0 08/04/2020
Initial release 🎉