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dc.contributor.authorOliveira, Joana S.
dc.contributor.authorHood, Lon L.
dc.contributor.authorLanglais, Benoit
dc.date.accessioned2019-11-07T19:10:53Z
dc.date.available2019-11-07T19:10:53Z
dc.date.issued2019-09-09
dc.identifier.citationOliveira, J. S., Hood, L. L., & Langlais, B. (2019). Constraining the early history of Mercury and its core dynamo by studying the crustal magnetic field. Journal of Geophysical Research: Planets, 124, 2382–2396. 2382. https://doi.org/10.1029/2019JE005938en_US
dc.identifier.issn2169-9097
dc.identifier.doi10.1029/2019je005938
dc.identifier.urihttp://hdl.handle.net/10150/635027
dc.description.abstractLow‐altitude magnetic field data acquired by MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) over a small portion of Mercury's surface revealed weak crustal magnetic field signatures. Here we study the crustal magnetic anomalies associated with impact craters on Mercury. We assume that the sources of these anomalies consist of impact melt, enriched in impactor iron. We assume that the subsurfaces of Mercury's impact craters have cooled in the presence of a constant global magnetic field, thus becoming thermoremanently magnetized. We invert for the crustal magnetization direction within five craters using a unidirectional magnetization model which assumes that the melt impact rocks recorded the constant core magnetic field present when the crater was formed and that the crater's magnetization has not been altered since its formation. From the best fitting magnetization direction we then obtain the corresponding north magnetic paleopole position assuming a centered core dipolar field. Results show that all five magnetic paleopoles lie in the southern hemisphere but are not required to be located near the present‐day magnetic pole, which lies near the south geographic pole. Accounting for the uncertainties, we show that our results all agree in a common small region that excludes the current magnetic pole. This strongly suggests that the dynamo has evolved with time. Our results represent valuable information for understanding the evolution of Mercury and emphasize the importance of including more anomaly analyses to complete and refine our conclusions.en_US
dc.description.sponsorshipESA Research Fellowship programme in Space Science; ANR Project MARMITE French National Research Agency (ANR) [ANR-13-BS05-0012]; University of Arizona, NASA DDAP; Region Pays de la Loire [2016-10982]en_US
dc.language.isoenen_US
dc.publisherAMER GEOPHYSICAL UNIONen_US
dc.rightsCopyright © 2019. American Geophysical Union. All Rights Reserved.en_US
dc.subjectMercuryen_US
dc.subjectmagnetic anomaliesen_US
dc.subjectParker's methoden_US
dc.titleConstraining the Early History of Mercury and Its Core Dynamo by Studying the Crustal Magnetic Fielden_US
dc.typeArticleen_US
dc.contributor.departmentUniv Arizona, Lunar & Planetary Laben_US
dc.identifier.journalJOURNAL OF GEOPHYSICAL RESEARCH-PLANETSen_US
dc.description.note6 month embargo; published online: 9 September 2019en_US
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en_US
dc.eprint.versionFinal published versionen_US
dc.source.volume124
dc.source.issue9
dc.source.beginpage2382-2396


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