Widespread Exposures of Extensive Clean Shallow Ice in the Mid-Latitudes of Mars
International audience Although ice in the Martian midlatitudes is typically covered by a layer of dust or regolith, it is exposed in some locations by fresh impact craters or in erosional scarps. In both cases, the exposed ice is massive or excess ice with a low lithic content. We find that erosion...
Published in: | Journal of Geophysical Research: Planets |
---|---|
Main Authors: | , , , , , , , , , , , , , , , |
Other Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2021
|
Subjects: | |
Online Access: | https://hal.science/hal-03186594 https://hal.science/hal-03186594/document https://hal.science/hal-03186594/file/Dundas_etal_ice_exposures_v11_revised5_4HAL.pdf https://doi.org/10.1029/2020JE006617 |
id |
ftunivnantes:oai:HAL:hal-03186594v1 |
---|---|
record_format |
openpolar |
spelling |
ftunivnantes:oai:HAL:hal-03186594v1 2023-11-12T04:27:22+01:00 Widespread Exposures of Extensive Clean Shallow Ice in the Mid-Latitudes of Mars Dundas, Colin, M Mellon, Michael, T Conway, Susan J. Daubar, Ingrid, J Williams, Kaj, E Ojha, Lujendra Wray, James, J Bramson, Ali, M Byrne, Shane Mcewen, Alfred, S Posiolova, Liliya, V Speth, Gunnar Viola, Donna Landis, Margaret, E Morgan, Gareth, A Pathare, Asmin, V US Geological Survey Flagstaff United States Geological Survey Reston (USGS) Laboratoire de Planétologie et Géodynamique UMR 6112 (LPG) Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST) Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) 2021 https://hal.science/hal-03186594 https://hal.science/hal-03186594/document https://hal.science/hal-03186594/file/Dundas_etal_ice_exposures_v11_revised5_4HAL.pdf https://doi.org/10.1029/2020JE006617 en eng HAL CCSD Wiley-Blackwell info:eu-repo/semantics/altIdentifier/doi/10.1029/2020JE006617 hal-03186594 https://hal.science/hal-03186594 https://hal.science/hal-03186594/document https://hal.science/hal-03186594/file/Dundas_etal_ice_exposures_v11_revised5_4HAL.pdf doi:10.1029/2020JE006617 info:eu-repo/semantics/OpenAccess ISSN: 2169-9097 EISSN: 2169-9100 Journal of Geophysical Research. Planets https://hal.science/hal-03186594 Journal of Geophysical Research. Planets, 2021, 126 (3), pp.e2020JE006617. ⟨10.1029/2020JE006617⟩ [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology info:eu-repo/semantics/article Journal articles 2021 ftunivnantes https://doi.org/10.1029/2020JE006617 2023-10-24T22:41:13Z International audience Although ice in the Martian midlatitudes is typically covered by a layer of dust or regolith, it is exposed in some locations by fresh impact craters or in erosional scarps. In both cases, the exposed ice is massive or excess ice with a low lithic content. We find that erosional scarps occur between 50° and 61° north and south latitude and that they are concentrated in and near Milankovič crater in the northern hemisphere and southeast of the Hellas basin in the southern hemisphere. These may represent locations of particularly thick or clean bodies of ice. Pits created by retreat of the scarps represent sublimation‐thermokarst landforms that evolve in a manner distinct from other ice‐loss landforms on Mars. New impact craters reveal that clean subsurface ice is widespread at middle‐ and high‐latitudes in both hemispheres at depths less than 1 m. Both the depth to ice and the ice content appear to exhibit significant variability over tens to hundreds of meters. The lowest‐latitude exposed ice is near 39°N and is at the edge of a region where impact exposures between 40° and 50°N are common, consistent with other indications of a high ice content. This lowest‐latitude ice may be currently unstable and subliming. Impact craters on lineated valley fill excavate ice blocks that may represent the top of debris‐covered glacial ice. Together, these landforms indicate widespread, clean subsurface ice at middle‐latitudes on Mars. The distribution and properties of this ice could provide information about past climate conditions. Article in Journal/Newspaper Thermokarst Université de Nantes: HAL-UNIV-NANTES Journal of Geophysical Research: Planets 126 3 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology |
spellingShingle |
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology Dundas, Colin, M Mellon, Michael, T Conway, Susan J. Daubar, Ingrid, J Williams, Kaj, E Ojha, Lujendra Wray, James, J Bramson, Ali, M Byrne, Shane Mcewen, Alfred, S Posiolova, Liliya, V Speth, Gunnar Viola, Donna Landis, Margaret, E Morgan, Gareth, A Pathare, Asmin, V Widespread Exposures of Extensive Clean Shallow Ice in the Mid-Latitudes of Mars |
topic_facet |
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology |
description |
International audience Although ice in the Martian midlatitudes is typically covered by a layer of dust or regolith, it is exposed in some locations by fresh impact craters or in erosional scarps. In both cases, the exposed ice is massive or excess ice with a low lithic content. We find that erosional scarps occur between 50° and 61° north and south latitude and that they are concentrated in and near Milankovič crater in the northern hemisphere and southeast of the Hellas basin in the southern hemisphere. These may represent locations of particularly thick or clean bodies of ice. Pits created by retreat of the scarps represent sublimation‐thermokarst landforms that evolve in a manner distinct from other ice‐loss landforms on Mars. New impact craters reveal that clean subsurface ice is widespread at middle‐ and high‐latitudes in both hemispheres at depths less than 1 m. Both the depth to ice and the ice content appear to exhibit significant variability over tens to hundreds of meters. The lowest‐latitude exposed ice is near 39°N and is at the edge of a region where impact exposures between 40° and 50°N are common, consistent with other indications of a high ice content. This lowest‐latitude ice may be currently unstable and subliming. Impact craters on lineated valley fill excavate ice blocks that may represent the top of debris‐covered glacial ice. Together, these landforms indicate widespread, clean subsurface ice at middle‐latitudes on Mars. The distribution and properties of this ice could provide information about past climate conditions. |
author2 |
US Geological Survey Flagstaff United States Geological Survey Reston (USGS) Laboratoire de Planétologie et Géodynamique UMR 6112 (LPG) Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST) Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Dundas, Colin, M Mellon, Michael, T Conway, Susan J. Daubar, Ingrid, J Williams, Kaj, E Ojha, Lujendra Wray, James, J Bramson, Ali, M Byrne, Shane Mcewen, Alfred, S Posiolova, Liliya, V Speth, Gunnar Viola, Donna Landis, Margaret, E Morgan, Gareth, A Pathare, Asmin, V |
author_facet |
Dundas, Colin, M Mellon, Michael, T Conway, Susan J. Daubar, Ingrid, J Williams, Kaj, E Ojha, Lujendra Wray, James, J Bramson, Ali, M Byrne, Shane Mcewen, Alfred, S Posiolova, Liliya, V Speth, Gunnar Viola, Donna Landis, Margaret, E Morgan, Gareth, A Pathare, Asmin, V |
author_sort |
Dundas, Colin, M |
title |
Widespread Exposures of Extensive Clean Shallow Ice in the Mid-Latitudes of Mars |
title_short |
Widespread Exposures of Extensive Clean Shallow Ice in the Mid-Latitudes of Mars |
title_full |
Widespread Exposures of Extensive Clean Shallow Ice in the Mid-Latitudes of Mars |
title_fullStr |
Widespread Exposures of Extensive Clean Shallow Ice in the Mid-Latitudes of Mars |
title_full_unstemmed |
Widespread Exposures of Extensive Clean Shallow Ice in the Mid-Latitudes of Mars |
title_sort |
widespread exposures of extensive clean shallow ice in the mid-latitudes of mars |
publisher |
HAL CCSD |
publishDate |
2021 |
url |
https://hal.science/hal-03186594 https://hal.science/hal-03186594/document https://hal.science/hal-03186594/file/Dundas_etal_ice_exposures_v11_revised5_4HAL.pdf https://doi.org/10.1029/2020JE006617 |
genre |
Thermokarst |
genre_facet |
Thermokarst |
op_source |
ISSN: 2169-9097 EISSN: 2169-9100 Journal of Geophysical Research. Planets https://hal.science/hal-03186594 Journal of Geophysical Research. Planets, 2021, 126 (3), pp.e2020JE006617. ⟨10.1029/2020JE006617⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2020JE006617 hal-03186594 https://hal.science/hal-03186594 https://hal.science/hal-03186594/document https://hal.science/hal-03186594/file/Dundas_etal_ice_exposures_v11_revised5_4HAL.pdf doi:10.1029/2020JE006617 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2020JE006617 |
container_title |
Journal of Geophysical Research: Planets |
container_volume |
126 |
container_issue |
3 |
_version_ |
1782340991406047232 |