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Unbiased analysis of geomagnetic data sets and comparison of historical data with paleomagnetic and archeomagnetic records
- Source :
- Reviews of Geophysics. 55:5-39
- Publication Year :
- 2017
- Publisher :
- American Geophysical Union (AGU), 2017.
-
Abstract
- Reconstructions of the past geomagnetic field provide fundamental constraints for understanding the dynamics of the Earth's interior, as well as serving as basis for magnetostratigraphic and archeomagnetic dating tools. Such reconstructions, when extending over epochs that precede the advent of instrumental measurements, rely exclusively on magnetic records from archeological artifacts, and, farther in the past, from rocks and sediments. The most critical component of such indirect records is field intensity because of possible biases introduced by material properties and by laboratory protocols, which do not reproduce exactly the original field recording conditions. Large biases are usually avoided by the use of appropriate checking procedures; however, smaller ones can remain undetected in individual studies and might significantly affect field reconstructions. We introduce a new general approach for analyzing geomagnetic databases in order to investigate the reliability of indirect records. This approach is based on the comparison of historical records with archeomagnetic and volcanic data, considering temporal and spatial mismatches with adequate weighting functions and error estimation. A good overall agreement is found between indirect records and historical measurements, while for several subsets systematic bias is detected (e.g, inclination shallowing of lava records). We also demonstrate that simple approaches to analyzing highly inhomogeneous and internally correlated paleomagnetic datasets can lead to incorrect conclusions about the efficiency of quality checks and corrections. Consistent criteria for selecting and weighting data are presented in this review and can be used to improve current geomagnetic field modeling techniques.
- Subjects :
- Paleomagnetism
Field intensity
010504 meteorology & atmospheric sciences
010502 geochemistry & geophysics
Geodesy
01 natural sciences
Field (computer science)
Weighting
Geophysics
Earth's magnetic field
Paleointensity
Geology
Reliability (statistics)
Historical record
0105 earth and related environmental sciences
Subjects
Details
- ISSN :
- 87551209
- Volume :
- 55
- Database :
- OpenAIRE
- Journal :
- Reviews of Geophysics
- Accession number :
- edsair.doi...........06f3f174e9440f13637b3b6947d1f8e4