The GEOMAGIA50 database for sediments complements data available from the Magnetics Information Consortium (Mag IC) database (), which has not been updated since 1999.
All data within SECVR00 will be transferred to GEOMAGIA50 and augmented with additional metadata.
The web query form is hosted at Unlike GEOMAGIA50 for archeological and volcanic materials, where data are primarily organized by age, the most important link between results from the same core, or between cores from the same location, is depth.
Ideally, the original core depth will be documented.
The period between 50 ka and the present contains a wealth of geomagnetic variability that we understand only in part.
Sediments deposited over this time have the advantage of being within the limits of radiocarbon dating, as well as being suitable for dating by other chronological methods (e.g., The power spectrum of geomagnetic dipole moment variations allows us to investigate the time necessary to average the geomagnetic field to obtain a stable time-average (if this exists).
Encouragingly, Holocene geomagnetic field models generate globally consistent time-averaged structures; however, in some studies, low-quality paleomagnetic data from sediments and/or erroneous age models can result in temporal ambiguities between records and therefore a distorted picture of the time-varying geomagnetic field.
The first step to understanding the evolution of the geomagnetic field over this time is the compilation and assessment of all available sediment records.
At least two geomagnetic field excursions (Mono Lake/Auckland and Laschamp) have been recorded at a number of globally distributed locations between 10 and 50 ka (e.g., Laj and Channell ) have revealed an ever more detailed picture of surface field changes.
Furthermore, additional excursion-like behavior has been noted at distinctly different times, e.g., the Hilina Pali/Tianchi excursion (Coe et al.
The GEOMAGIA50 database for sediments builds upon the principles described in Korhonen et al.
(’ section) has been significantly expanded to accommodate the greater diversity of magnetic measurements made on lake and marine sediments and the large number of dating methods applicable.