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dc.contributor.authorBramson, A. M.
dc.contributor.authorByrne, Shane
dc.contributor.authorBapst, J.
dc.date.accessioned2018-01-31T16:05:15Z
dc.date.available2018-01-31T16:05:15Z
dc.date.issued2017-11
dc.identifier.citationPreservation of Midlatitude Ice Sheets on Mars 2017, 122 (11):2250 Journal of Geophysical Research: Planetsen
dc.identifier.issn21699097
dc.identifier.doi10.1002/2017JE005357
dc.identifier.urihttp://hdl.handle.net/10150/626448
dc.description.abstractExcess ice with a minimum age of tens of millions of years is widespread in Arcadia Planitia on Mars, and a similar deposit has been found in Utopia Planitia. The conditions that led to the formation and preservation of these midlatitude ice sheets hold clues to past climate and subsurface structure on Mars. We simulate the thermal stability and retreat of buried excess ice sheets over 21Myr of Martian orbital solutions and find that the ice sheets can be orders of magnitude older than the obliquity cycles that are typically thought to drive midlatitude ice deposition and sublimation. Retreat of this ice in the last 4Myr could have contributed similar to 6% of the volume of the north polar layered deposits (NPLD) and more than 10% if the NPLD are older than 4Myr. Matching the measured dielectric constants of the Arcadia and Utopia Planitia deposits requires ice porosities of similar to 25-35%. We model geothermally driven vapor migration through porous ice under Martian temperatures and find that Martian firn may be able to maintain porosity for timescales longer than we predict for retreat of the ice.
dc.description.sponsorshipNational Science Foundation (NSF) [DGE-1143953]; NASA Earth and Space Sciences Fellowship (NESSF) [NNX16AP09H]; NASA Mars Data Analysis Program (MDAP) award [NNX15AM62G]en
dc.language.isoenen
dc.publisherAMER GEOPHYSICAL UNIONen
dc.relation.urlhttp://doi.wiley.com/10.1002/2017JE005357en
dc.rights©2017. American Geophysical Union. All Rights Reserved.en
dc.subjectMarsen
dc.subjecticeen
dc.subjectthermal stabilityen
dc.subjectmidlatitudesen
dc.subjectobliquity cyclesen
dc.subjectsublimation lagen
dc.titlePreservation of Midlatitude Ice Sheets on Marsen
dc.typeArticleen
dc.contributor.departmentUniv Arizona, Lunar & Planetary Laben
dc.identifier.journalJournal of Geophysical Research: Planetsen
dc.description.note6 month embargo; published online: 9 November 2017en
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
dc.eprint.versionFinal published versionen
dc.contributor.institutionLunar and Planetary Laboratory; University of Arizona; Tucson AZ USA
dc.contributor.institutionLunar and Planetary Laboratory; University of Arizona; Tucson AZ USA
dc.contributor.institutionLunar and Planetary Laboratory; University of Arizona; Tucson AZ USA
refterms.dateFOA2018-05-09T00:00:00Z
html.description.abstractExcess ice with a minimum age of tens of millions of years is widespread in Arcadia Planitia on Mars, and a similar deposit has been found in Utopia Planitia. The conditions that led to the formation and preservation of these midlatitude ice sheets hold clues to past climate and subsurface structure on Mars. We simulate the thermal stability and retreat of buried excess ice sheets over 21Myr of Martian orbital solutions and find that the ice sheets can be orders of magnitude older than the obliquity cycles that are typically thought to drive midlatitude ice deposition and sublimation. Retreat of this ice in the last 4Myr could have contributed similar to 6% of the volume of the north polar layered deposits (NPLD) and more than 10% if the NPLD are older than 4Myr. Matching the measured dielectric constants of the Arcadia and Utopia Planitia deposits requires ice porosities of similar to 25-35%. We model geothermally driven vapor migration through porous ice under Martian temperatures and find that Martian firn may be able to maintain porosity for timescales longer than we predict for retreat of the ice.


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