How the Martian Residual South Polar Cap Develops Quasi-Circular and Heart-Shaped Pits, Troughs, and Moats
The martian Residual South Polar Cap (RSPC) is a 1-10 m thick deposit of permanent CO_2 ice perched on the much larger H_2O ice cap. The CO_2 ice is dissected into mesas by erosional landforms that can be broadly classified as (i) quasi-circular pits, (ii) heart-shaped pits, (iii) linear troughs, an...
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ftcaltechauth:oai:authors.library.caltech.edu:73535 2023-05-15T16:38:18+02:00 How the Martian Residual South Polar Cap Develops Quasi-Circular and Heart-Shaped Pits, Troughs, and Moats Buhler, Peter B. Ingersoll, Andrew P. Ehlmann, Bethany L. Fassett, Caleb I. Head, James W. 2017-04 application/pdf https://authors.library.caltech.edu/73535/ https://authors.library.caltech.edu/73535/2/1-s2.0-S0019103516304171-main.pdf https://resolver.caltech.edu/CaltechAUTHORS:20170118-154814373 en eng Elsevier https://authors.library.caltech.edu/73535/2/1-s2.0-S0019103516304171-main.pdf Buhler, Peter B. and Ingersoll, Andrew P. and Ehlmann, Bethany L. and Fassett, Caleb I. and Head, James W. (2017) How the Martian Residual South Polar Cap Develops Quasi-Circular and Heart-Shaped Pits, Troughs, and Moats. Icarus, 286 . pp. 69-93. ISSN 0019-1035. doi:10.1016/j.icarus.2017.01.012. https://resolver.caltech.edu/CaltechAUTHORS:20170118-154814373 <https://resolver.caltech.edu/CaltechAUTHORS:20170118-154814373> cc_by_nc_nd CC-BY-NC-ND Article PeerReviewed 2017 ftcaltechauth https://doi.org/10.1016/j.icarus.2017.01.012 2021-11-18T18:40:25Z The martian Residual South Polar Cap (RSPC) is a 1-10 m thick deposit of permanent CO_2 ice perched on the much larger H_2O ice cap. The CO_2 ice is dissected into mesas by erosional landforms that can be broadly classified as (i) quasi-circular pits, (ii) heart-shaped pits, (iii) linear troughs, and (iv) moats. We use HiRISE (25-50 cm/px) images taken at a cadence of days to months to track meter-scale changes in the RSPC in order to investigate the mechanisms that lead to the development of these four distinct morphologies. For the first time, we report the development of dark fans on the sides of the CO_2 mesas and the fracturing and deterioration of the initially smooth upper surface of CO_2 mesas. We interpret these features as indicating the sublimation and subsequent escape of CO_2 from the interiors of mesas, which undermines structural support of mesa tops, causing them to collapse. The collapse of mesa tops, along with uneven deposition of CO_2 ice, creates steep scarps that erode during the summer due to preferential sunlight absorption. During the winter, CO_2 deposition acts to smooth topography, creating gently sloping ramps. We propose that the interplay between the steep scarps and gentle slopes leads to either quasi-circular pits, heart-shaped pits, linear troughs, or moats, depending on local conditions. Article in Journal/Newspaper Ice cap Caltech Authors (California Institute of Technology) Icarus 286 69 93 |
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Caltech Authors (California Institute of Technology) |
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English |
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The martian Residual South Polar Cap (RSPC) is a 1-10 m thick deposit of permanent CO_2 ice perched on the much larger H_2O ice cap. The CO_2 ice is dissected into mesas by erosional landforms that can be broadly classified as (i) quasi-circular pits, (ii) heart-shaped pits, (iii) linear troughs, and (iv) moats. We use HiRISE (25-50 cm/px) images taken at a cadence of days to months to track meter-scale changes in the RSPC in order to investigate the mechanisms that lead to the development of these four distinct morphologies. For the first time, we report the development of dark fans on the sides of the CO_2 mesas and the fracturing and deterioration of the initially smooth upper surface of CO_2 mesas. We interpret these features as indicating the sublimation and subsequent escape of CO_2 from the interiors of mesas, which undermines structural support of mesa tops, causing them to collapse. The collapse of mesa tops, along with uneven deposition of CO_2 ice, creates steep scarps that erode during the summer due to preferential sunlight absorption. During the winter, CO_2 deposition acts to smooth topography, creating gently sloping ramps. We propose that the interplay between the steep scarps and gentle slopes leads to either quasi-circular pits, heart-shaped pits, linear troughs, or moats, depending on local conditions. |
format |
Article in Journal/Newspaper |
author |
Buhler, Peter B. Ingersoll, Andrew P. Ehlmann, Bethany L. Fassett, Caleb I. Head, James W. |
spellingShingle |
Buhler, Peter B. Ingersoll, Andrew P. Ehlmann, Bethany L. Fassett, Caleb I. Head, James W. How the Martian Residual South Polar Cap Develops Quasi-Circular and Heart-Shaped Pits, Troughs, and Moats |
author_facet |
Buhler, Peter B. Ingersoll, Andrew P. Ehlmann, Bethany L. Fassett, Caleb I. Head, James W. |
author_sort |
Buhler, Peter B. |
title |
How the Martian Residual South Polar Cap Develops Quasi-Circular and Heart-Shaped Pits, Troughs, and Moats |
title_short |
How the Martian Residual South Polar Cap Develops Quasi-Circular and Heart-Shaped Pits, Troughs, and Moats |
title_full |
How the Martian Residual South Polar Cap Develops Quasi-Circular and Heart-Shaped Pits, Troughs, and Moats |
title_fullStr |
How the Martian Residual South Polar Cap Develops Quasi-Circular and Heart-Shaped Pits, Troughs, and Moats |
title_full_unstemmed |
How the Martian Residual South Polar Cap Develops Quasi-Circular and Heart-Shaped Pits, Troughs, and Moats |
title_sort |
how the martian residual south polar cap develops quasi-circular and heart-shaped pits, troughs, and moats |
publisher |
Elsevier |
publishDate |
2017 |
url |
https://authors.library.caltech.edu/73535/ https://authors.library.caltech.edu/73535/2/1-s2.0-S0019103516304171-main.pdf https://resolver.caltech.edu/CaltechAUTHORS:20170118-154814373 |
genre |
Ice cap |
genre_facet |
Ice cap |
op_relation |
https://authors.library.caltech.edu/73535/2/1-s2.0-S0019103516304171-main.pdf Buhler, Peter B. and Ingersoll, Andrew P. and Ehlmann, Bethany L. and Fassett, Caleb I. and Head, James W. (2017) How the Martian Residual South Polar Cap Develops Quasi-Circular and Heart-Shaped Pits, Troughs, and Moats. Icarus, 286 . pp. 69-93. ISSN 0019-1035. doi:10.1016/j.icarus.2017.01.012. https://resolver.caltech.edu/CaltechAUTHORS:20170118-154814373 <https://resolver.caltech.edu/CaltechAUTHORS:20170118-154814373> |
op_rights |
cc_by_nc_nd |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1016/j.icarus.2017.01.012 |
container_title |
Icarus |
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286 |
container_start_page |
69 |
op_container_end_page |
93 |
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1766028573193273344 |