Centennial- to Millennial-Scale Geomagnetic Field Variations

摘要: This chapter describes the paleomagnetic data that are available for studying geomagnetic field on centennial to millennial timescales, concentrating record past 10 000 years. Various types of and their geographic temporal coverage discussed together with an assessment quality limitations imposed by age constraints commonly available. The basic methods used both regional global syntheses outlined. Regional secular variation curves provide a means assess scale often magnetic dating, is, generate materials otherwise unknown or questionable chronologies. Commonly vary widely, ranging from eyeball fits features in disparate records sophisticated Bayesian techniques. Global modeling has allowed development low-resolution time-varying spherical harmonic descriptions behavior. In geomagnetism, these evaluate persistence like high-latitude flux patches found historical field, determine extent which westward eastward drifts have contributed variations, monitor changes dipole moment over 10 ky. Predictions models compared conventional proxies virtual poles variations. current rate change lies within range variations seen Some applications millennial-scale studies other fields briefly discussed: reconstruction events, separation solar influences cosmogenic nuclide production rates, exposure high-resolution magnetostratigraphic applications. concludes prospects further developments Holocene list electronic resources models.