Millennial Variations of the Geomagnetic Field: from Data Recovery to Field Reconstruction

New directional archeomagnetic data of burned cave sediments from Switzerland and geomagnetic field variations in Central Europe

“…In contrast, archaeological artefacts have been shown to be faithfull recorders of the Holocene geomagnetic field, particularly for the last 3000 yr (cf. Donadini et al 2010;Pavón-Carrasco et al 2010). Data coming from burned archaeological structures and burned sediments are temporarily better constrained in capturing the geomagnetic field.…”

Probability uniformization and application to statistical palaeomagnetic field models and directional data

“…Reconstructing the large scales of the field over the past few millennia is also possible, thanks to archeomagnetic data (e.g. Donadini et al 2010), but going further back in time requires the use of palaeomagnetic data, that is, of palaeomagnetic field estimates reconstructed from rocks magnetized in the palaeofield. Unfortunately, age control of these rocks rarely ensures that data collected at various locations at the Earth's surface are synchronous enough (compared to the typical timescales involved in the field evolution, see, e.g.…”

Centennial to millennial geomagnetic field variations

“…One of the latest, most comprehensive data collections is described by Donadini et al (2009), to which 13 more sediment records have been added for more recent modelling work by . The past field information is gained from a variety of materials through a range of different laboratory procedures (see, e.g., Donadini et al 2010, for a recent review). Consequently, the accuracy and reliability of the data vary notably and can affect field reconstructions in different ways.…”

“…These experiments, however, often fail stringent quality checks and the uncertainties associated with paleointensity data are generally large (e.g., Donadini et al 2010). Uncertainties in the ages of these kind of data should in general be no larger than those of the dating methods, as the natural cooling process during which the magnetisation is acquired is comparatively fast.…”

“…However, missing or extremely fine layers may adulterate the results, and the experimental sample size also leads to magnetic results which are integrating over at least a couple of years. More details about sediment record characteristics and dating can be found, e.g., in the review by Donadini et al (2010). Fig.…”