Intrinsic paleointensity bias and the long-term history of the geodynamo.

ABSTRACT: Many geodynamo models predict an inverse relationship between geomagnetic reversal frequency and field strength. However, most of the absolute paleointensity data, obtained predominantly by the Thellier method from bulk volcanic rocks, fail to confirm this relationship. Although low paleointensities are commonly observed during periods of high reversal rate (notably, in the late Jurassic), higher than present-day intensity values are rare during periods of no or few reversals (superchrons). We have identified a fundamental mechanism that results in a pervasive and previously unrecognized low-field bias that affects most paleointensity data in the global database. Our results provide an explanation for the discordance between the experimental data and numerical models, and lend additional s

SUBMITTER: Smirnov AV 

PROVIDER: S-EPMC5310827 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature