Matches in SemOpenAlex for { <https://semopenalex.org/work/W2076247669> ?p ?o ?g. }
- W2076247669 endingPage "156" @default.
- W2076247669 startingPage "145" @default.
- W2076247669 abstract "Recent studies (Ben-Yosef et al., 2009, Shaar et al., 2011) propose extreme archeomagnetic intensity changes (termed spikes) in the range ∼4–5μT/year c.a. 1000 BC in the Near East, around 40 to 50 times larger than values typical of the present-day. In order to investigate whether such extreme changes are consistent with a model of the source region of the magnetic field, namely the fluid flow at the surface of Earth's core, we construct upper bounds for instantaneous magnetic intensity change at an arbitrary site on the Earth's surface. These bounds are constrained by the amount of kinetic energy available to sustain the change, taken here to be a prescribed value for the root-mean-squared surface velocity of 13 km/yr as inferred from the current state of the core. Further, we focus attention on two end-members of optimised core surface flow structure: unrestricted and purely-toroidal. As the derivation of the bounds demands complete knowledge of the geomagnetic field at the core surface, we model the unknown field by means of a Monte Carlo approach, extending to high degree the CHAOS-4 (epoch 2010 AD) and CALS10k1.b (epoch 1000 BC) geomagnetic field models. Using 2000 realisations for each family of stochastic field models, we find that optimised core flows are always large-scale and that they tend to generate a non-dipole, quadrupole-dominated secular variation at the Earth's surface. The dependence of the upper bounds as a function of site location reflects the large-scale structure of the intensity itself: stronger field permits more rapid change. For the site in the Near East, purely-toroidal flows have upper bounds of approximately 0.62±0.02μT/year, whereas unrestricted flows increase this bound to 1.20±0.02μT/year. We favour the former as more geophysically sound, on the account of a large body of previous results from core surface flow inversions and consistency with the existence of a stratified layer at the top of the core. Even if we allow for a generous threefold increase in the prescribed rms velocity (and a concomitant threefold increase in the bound), we conclude that the reported occurrences of extreme intensity changes as suggested in the Near East are not compatible with the commonly accepted structure of core–surface flow. However, it may be that an explanation for spikes lies beyond our current perception of core-dynamics and future work would be further motivated by seeking corroborative evidence of rapid intensity change from sites elsewhere on Earth's surface; we therefore also discuss the form that the secular variation would take in the case of simultanenous archeomagnetic spikes." @default.
- W2076247669 created "2016-06-24" @default.
- W2076247669 creator A5035390538 @default.
- W2076247669 creator A5073181839 @default.
- W2076247669 creator A5079297873 @default.
- W2076247669 date "2014-02-01" @default.
- W2076247669 modified "2023-09-30" @default.
- W2076247669 title "Core-flow constraints on extreme archeomagnetic intensity changes" @default.
- W2076247669 cites W1503747008 @default.
- W2076247669 cites W1668662863 @default.
- W2076247669 cites W1893707444 @default.
- W2076247669 cites W1908995290 @default.
- W2076247669 cites W1932508272 @default.
- W2076247669 cites W1978891174 @default.
- W2076247669 cites W1979070161 @default.
- W2076247669 cites W1980373314 @default.
- W2076247669 cites W1985036388 @default.
- W2076247669 cites W2006248364 @default.
- W2076247669 cites W2019293669 @default.
- W2076247669 cites W2030702522 @default.
- W2076247669 cites W2038421862 @default.
- W2076247669 cites W2042342067 @default.
- W2076247669 cites W2050096245 @default.
- W2076247669 cites W2063753023 @default.
- W2076247669 cites W2068487300 @default.
- W2076247669 cites W2074959685 @default.
- W2076247669 cites W2083179196 @default.
- W2076247669 cites W2084972032 @default.
- W2076247669 cites W2088953091 @default.
- W2076247669 cites W2093955130 @default.
- W2076247669 cites W2094646879 @default.
- W2076247669 cites W2102485713 @default.
- W2076247669 cites W2102906969 @default.
- W2076247669 cites W2107074920 @default.
- W2076247669 cites W2111567503 @default.
- W2076247669 cites W2112275977 @default.
- W2076247669 cites W2112869411 @default.
- W2076247669 cites W2124352278 @default.
- W2076247669 cites W2140149693 @default.
- W2076247669 cites W2142589746 @default.
- W2076247669 cites W2146257251 @default.
- W2076247669 cites W2146499315 @default.
- W2076247669 cites W2156328490 @default.
- W2076247669 cites W2162525706 @default.
- W2076247669 cites W2163671534 @default.
- W2076247669 cites W2171577882 @default.
- W2076247669 cites W4234685170 @default.
- W2076247669 doi "https://doi.org/10.1016/j.epsl.2013.11.020" @default.
- W2076247669 hasPublicationYear "2014" @default.
- W2076247669 type Work @default.
- W2076247669 sameAs 2076247669 @default.
- W2076247669 citedByCount "53" @default.
- W2076247669 countsByYear W20762476692014 @default.
- W2076247669 countsByYear W20762476692015 @default.
- W2076247669 countsByYear W20762476692016 @default.
- W2076247669 countsByYear W20762476692017 @default.
- W2076247669 countsByYear W20762476692018 @default.
- W2076247669 countsByYear W20762476692019 @default.
- W2076247669 countsByYear W20762476692020 @default.
- W2076247669 countsByYear W20762476692021 @default.
- W2076247669 countsByYear W20762476692022 @default.
- W2076247669 countsByYear W20762476692023 @default.
- W2076247669 crossrefType "journal-article" @default.
- W2076247669 hasAuthorship W2076247669A5035390538 @default.
- W2076247669 hasAuthorship W2076247669A5073181839 @default.
- W2076247669 hasAuthorship W2076247669A5079297873 @default.
- W2076247669 hasBestOaLocation W20762476691 @default.
- W2076247669 hasConcept C121332964 @default.
- W2076247669 hasConcept C127313418 @default.
- W2076247669 hasConcept C13280743 @default.
- W2076247669 hasConcept C159985019 @default.
- W2076247669 hasConcept C165205528 @default.
- W2076247669 hasConcept C192562407 @default.
- W2076247669 hasConcept C2164484 @default.
- W2076247669 hasConcept C62520636 @default.
- W2076247669 hasConcept C8058405 @default.
- W2076247669 hasConcept C93038891 @default.
- W2076247669 hasConceptScore W2076247669C121332964 @default.
- W2076247669 hasConceptScore W2076247669C127313418 @default.
- W2076247669 hasConceptScore W2076247669C13280743 @default.
- W2076247669 hasConceptScore W2076247669C159985019 @default.
- W2076247669 hasConceptScore W2076247669C165205528 @default.
- W2076247669 hasConceptScore W2076247669C192562407 @default.
- W2076247669 hasConceptScore W2076247669C2164484 @default.
- W2076247669 hasConceptScore W2076247669C62520636 @default.
- W2076247669 hasConceptScore W2076247669C8058405 @default.
- W2076247669 hasConceptScore W2076247669C93038891 @default.
- W2076247669 hasLocation W20762476691 @default.
- W2076247669 hasLocation W20762476692 @default.
- W2076247669 hasLocation W20762476693 @default.
- W2076247669 hasOpenAccess W2076247669 @default.
- W2076247669 hasPrimaryLocation W20762476691 @default.
- W2076247669 hasRelatedWork W1968702681 @default.
- W2076247669 hasRelatedWork W2031573214 @default.
- W2076247669 hasRelatedWork W2092739438 @default.
- W2076247669 hasRelatedWork W2371527909 @default.
- W2076247669 hasRelatedWork W2528876452 @default.
- W2076247669 hasRelatedWork W2772196783 @default.