{"@context":{"@vocab":"https://cir.nii.ac.jp/schema/1.0/","rdfs":"http://www.w3.org/2000/01/rdf-schema#","dc":"http://purl.org/dc/elements/1.1/","dcterms":"http://purl.org/dc/terms/","foaf":"http://xmlns.com/foaf/0.1/","prism":"http://prismstandard.org/namespaces/basic/2.0/","cinii":"http://ci.nii.ac.jp/ns/1.0/","datacite":"https://schema.datacite.org/meta/kernel-4/","ndl":"http://ndl.go.jp/dcndl/terms/","jpcoar":"https://github.com/JPCOAR/schema/blob/master/2.0/"},"@id":"https://cir.nii.ac.jp/crid/1361699993384595328.json","@type":"Article","productIdentifier":[{"identifier":{"@type":"DOI","@value":"10.1186/bf03352728"}},{"identifier":{"@type":"URI","@value":"https://link.springer.com/content/pdf/10.1186/BF03352728.pdf"}},{"identifier":{"@type":"URI","@value":"https://link.springer.com/article/10.1186/BF03352728/fulltext.html"}},{"identifier":{"@type":"URI","@value":"http://link.springer.com/content/pdf/10.1186/BF03352728"}}],"dc:title":[{"@value":"Geomagnetic constraints on stratification at the top of Earth’s core"}],"description":[{"type":"abstract","notation":[{"@value":"<jats:title>Abstract</jats:title>\n          <jats:p>The geodynamo requires that at least part of the Earth’s liquid core be convecting so vigorously as to mix it thoroughly to uniform composition and adiabatic temperature. It is possible, however, that part of liquid core is stably stratified, either thermally because of a low temperature gradient or compositionally because light material has separated out. The top of the outer core is the most likely site for stability because the adiabat is steepest there and because light material will rise to the surface. Here I show that part of the observed secular variation, that associated with flux expulsion in the southern hemisphere, can only be caused by fluid upwelling in the electromagnetic boundary layer at the top of the core or by very strong poloidal field gradients at the top of the core. Any stratified layer is limited to roughly the uppermost 100 km if flux expulsion is the mechanism; if the layer is any thicker the region in the southern hemisphere where reverse flux patches are growing must also be the site of very strong field gradients caused by very strong near-surface shear flows.</jats:p>"}]}],"creator":[{"@id":"https://cir.nii.ac.jp/crid/1381699993384595328","@type":"Researcher","foaf:name":[{"@value":"David Gubbins"}]}],"publication":{"publicationIdentifier":[{"@type":"EISSN","@value":"18805981"}],"prism:publicationName":[{"@value":"Earth, Planets and Space"}],"dc:publisher":[{"@value":"Springer Science and Business Media LLC"}],"prism:publicationDate":"2007-07","prism:volume":"59","prism:number":"7","prism:startingPage":"661","prism:endingPage":"664"},"reviewed":"false","dc:rights":["https://creativecommons.org/licenses/by/4.0/","https://creativecommons.org/licenses/by/4.0/"],"url":[{"@id":"https://link.springer.com/content/pdf/10.1186/BF03352728.pdf"},{"@id":"https://link.springer.com/article/10.1186/BF03352728/fulltext.html"},{"@id":"http://link.springer.com/content/pdf/10.1186/BF03352728"}],"createdAt":"2014-08-15","modifiedAt":"2021-09-02","relatedProduct":[{"@id":"https://cir.nii.ac.jp/crid/1360002216113773440","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"The high conductivity of iron and thermal evolution of the Earth’s core"}]},{"@id":"https://cir.nii.ac.jp/crid/1360004236296920704","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Composition and State of the Core"}]},{"@id":"https://cir.nii.ac.jp/crid/1360565166067204736","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"An implication for the origin of stratification below the core–mantle boundary region in numerical dynamo simulations in a rotating spherical shell"}]},{"@id":"https://cir.nii.ac.jp/crid/1360567182379075072","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"On the thermo-chemical origin of the stratified region at the top of the Earth’s core"}]},{"@id":"https://cir.nii.ac.jp/crid/1360849946243345536","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Ab Initio Study on the Lower Mantle Minerals"}]},{"@id":"https://cir.nii.ac.jp/crid/1360865816786642944","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Assessment of a Stable Region of Earth's Core Requiring Magnetic Field Generation over Four Billion Years"}]},{"@id":"https://cir.nii.ac.jp/crid/2050870367075051904","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Effect of core electrical conductivity on core surface flow models"}]}],"dataSourceIdentifier":[{"@type":"CROSSREF","@value":"10.1186/bf03352728"},{"@type":"CROSSREF","@value":"10.1146/annurev-earth-050212-124007_references_DOI_Q1s10TFwimHkbtRBWpSbdpVtREx"},{"@type":"CROSSREF","@value":"10.1016/j.pepi.2017.05.011_references_DOI_Q1s10TFwimHkbtRBWpSbdpVtREx"},{"@type":"CROSSREF","@value":"10.1186/s40623-020-01269-0_references_DOI_Q1s10TFwimHkbtRBWpSbdpVtREx"},{"@type":"CROSSREF","@value":"10.1146/annurev-earth-071719-055139_references_DOI_Q1s10TFwimHkbtRBWpSbdpVtREx"},{"@type":"CROSSREF","@value":"10.1002/9781119526919.ch9_references_DOI_Q1s10TFwimHkbtRBWpSbdpVtREx"},{"@type":"CROSSREF","@value":"10.1016/j.pepi.2015.02.007_references_DOI_Q1s10TFwimHkbtRBWpSbdpVtREx"},{"@type":"CROSSREF","@value":"10.1016/j.pepi.2013.07.010_references_DOI_Q1s10TFwimHkbtRBWpSbdpVtREx"}]}