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Scenarios for the formation of Chasma Boreale, Mars
| Title: | Scenarios for the formation of Chasma Boreale, Mars |
| Authors: | Greve, Ralf Browse this author →KAKEN DB |
| Keywords: | Mars | | Polar cap | | Chasma Boreale | | Geothermal heat flux | | Jökulhlaup |
| Issue Date: | Aug-2008 |
| Publisher: | Academic Press |
| Journal Title: | Icarus |
| Volume: | 196 |
| Issue: | 2 |
| Start Page: | 359 |
| End Page: | 367 |
| Publisher DOI: | 10.1016/j.icarus.2007.10.020 |
| Abstract: | The Martian polar caps feature large chasmata and smaller trough systems which have no counterpart in terrestrial ice sheets. Chasma Boreale cuts about 500 km into the western part of the north-polar cap, is up to 100 km wide and up to 2 km deep. One possible formation mechanism is by a temporary heat source under the ice due to tectonothermal or volcanic activity, which melts the ice from below. It is demonstrated by model simulations that this process is feasible, a moderately increased heat flux of 0.5–1Wm−2, sustained over at least tens of thousands of years, producing a topographic depression which resembles the real chasma. Associated meltwater discharge rates are small (< 1km3 a−1), but can exceed 10km3 a−1 if a stronger heat flux of 10Wm−2 is assumed. Local ice-flow velocities during the process of chasma formation can exceed 1ma−1 at the head and scarps of the chasma. However, if the thermal anomaly shuts down, glacial flow quickly decreases, so that the chasma can stay open for an indefinite amount of time without an ongoing, sustaining process under the climate conditions of the most recent millions of years. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/34403 |
| Appears in Collections: | 低温科学研究所 (Institute of Low Temperature Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: Greve Ralf
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