Source: Journal of Geophysical Research: Solid Earth
The geomagnetic field shows regional changes in declination (angle with geographic north), inclination (angle with the horizontal), and intensity on centennial time scales, known as paleosecular variation (PSV). By making use of dated archeological artifacts, so-called PSV master curves have been put together tracing the field behavior for the most recent millennia for several regions on Earth, with a focus on declination and inclination trends because getting good quality intensity from archeological artifacts is considerably more tedious.
Jones et al.  have unlocked the vast USA PSV legacy database that was until now surprisingly poorly accessible. Those legacy data represent 60 years of research effort and was resting in the laboratory archives of three of America’s archeomagnetism giants: Dubois, Wolfman, and Eighmy. The authors performed a Herculean job: they had to return to the raw data archives, put all data on common and modern standards, essentially redo the data interpretation, and apply today’s reliability criteria which are much stricter than those in use in the 1960s-1990s (only 1185 out of 5377 archeological sites passed).
The result is worth the effort: A new robust regional PSV curve is established for the Four Corners region in the USA that reconciles previous partly conflicting curves, enabling precise dating of Native American structures. Further, having these data now available in accessible data bases will lead to significantly improved geomagnetic field models (both regional and global).
Citation: Jones, S. A., Blinman, E., Tauxe, L., Cox, J. R., Lengyel, S., Sternberg, R., et al. . MagIC as a FAIR repository for America’s directional archaeomagnetic legacy data. Journal of Geophysical Research: Solid Earth, 126, e2021JB022874. https://doi.org/10.1029/2021JB022874
—Mark J. Dekkers, Editor, JGR: Solid Earth