Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole Today
Abstract Recent analysis of radar data from the Mars Express spacecraft has interpreted bright subsurface radar reflections as indicators of local liquid water at the base of the south polar layered deposits (SPLD). However, the physical and geological conditions required to produce melting at this...
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| Format: | Article |
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Wiley
2019-02-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1029/2018GL080985 |
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| author | Michael M. Sori Ali M. Bramson |
| author_facet | Michael M. Sori Ali M. Bramson |
| author_sort | Michael M. Sori |
| collection | DOAJ |
| description | Abstract Recent analysis of radar data from the Mars Express spacecraft has interpreted bright subsurface radar reflections as indicators of local liquid water at the base of the south polar layered deposits (SPLD). However, the physical and geological conditions required to produce melting at this location were not quantified. Here we use thermophysical models to constrain parameters necessary to generate liquid water beneath the SPLD. We show that no concentration of salt is sufficient to melt ice at the base of the SPLD in the present day under typical Martian conditions. Instead, a local enhancement in the geothermal heat flux of >72 mW/m2 is required, even under the most favorable compositional considerations. This heat flow is most simply achieved via the presence of a subsurface magma chamber emplaced 100 s of kyr ago. Thus, if the liquid water interpretation of the observations is correct, magmatism on Mars may have been active extremely recently. |
| format | Article |
| id | doaj-art-e2e9b1e227d1467f887c66f50eda6779 |
| institution | OA Journals |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2019-02-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-e2e9b1e227d1467f887c66f50eda67792025-08-20T01:51:45ZengWileyGeophysical Research Letters0094-82761944-80072019-02-014631222123110.1029/2018GL080985Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole TodayMichael M. Sori0Ali M. Bramson1Lunar and Planetary Laboratory University of Arizona Tucson AZ USALunar and Planetary Laboratory University of Arizona Tucson AZ USAAbstract Recent analysis of radar data from the Mars Express spacecraft has interpreted bright subsurface radar reflections as indicators of local liquid water at the base of the south polar layered deposits (SPLD). However, the physical and geological conditions required to produce melting at this location were not quantified. Here we use thermophysical models to constrain parameters necessary to generate liquid water beneath the SPLD. We show that no concentration of salt is sufficient to melt ice at the base of the SPLD in the present day under typical Martian conditions. Instead, a local enhancement in the geothermal heat flux of >72 mW/m2 is required, even under the most favorable compositional considerations. This heat flow is most simply achieved via the presence of a subsurface magma chamber emplaced 100 s of kyr ago. Thus, if the liquid water interpretation of the observations is correct, magmatism on Mars may have been active extremely recently.https://doi.org/10.1029/2018GL080985basal meltingwatermagmatismthermal modelingMarssalts |
| spellingShingle | Michael M. Sori Ali M. Bramson Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole Today Geophysical Research Letters basal melting water magmatism thermal modeling Mars salts |
| title | Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole Today |
| title_full | Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole Today |
| title_fullStr | Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole Today |
| title_full_unstemmed | Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole Today |
| title_short | Water on Mars, With a Grain of Salt: Local Heat Anomalies Are Required for Basal Melting of Ice at the South Pole Today |
| title_sort | water on mars with a grain of salt local heat anomalies are required for basal melting of ice at the south pole today |
| topic | basal melting water magmatism thermal modeling Mars salts |
| url | https://doi.org/10.1029/2018GL080985 |
| work_keys_str_mv | AT michaelmsori wateronmarswithagrainofsaltlocalheatanomaliesarerequiredforbasalmeltingoficeatthesouthpoletoday AT alimbramson wateronmarswithagrainofsaltlocalheatanomaliesarerequiredforbasalmeltingoficeatthesouthpoletoday |