Cargando…
Longitudinal ridges imparted by high-speed granular flow mechanisms in martian landslides
The presence of longitudinal ridges documented in long runout landslides across our solar system is commonly associated with the existence of a basal layer of ice. However, their development, the link between their occurrence and the emplacement mechanisms of long runout landslides, and the necessit...
Autores principales: | , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2019
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6813353/ https://www.ncbi.nlm.nih.gov/pubmed/31649236 http://dx.doi.org/10.1038/s41467-019-12734-0 |
_version_ | 1783462822889390080 |
---|---|
author | Magnarini, Giulia Mitchell, Thomas M. Grindrod, Peter M. Goren, Liran Schmitt, Harrison H. |
author_facet | Magnarini, Giulia Mitchell, Thomas M. Grindrod, Peter M. Goren, Liran Schmitt, Harrison H. |
author_sort | Magnarini, Giulia |
collection | PubMed |
description | The presence of longitudinal ridges documented in long runout landslides across our solar system is commonly associated with the existence of a basal layer of ice. However, their development, the link between their occurrence and the emplacement mechanisms of long runout landslides, and the necessity of a basal ice layer remain poorly understood. Here, we analyse the morphometry of longitudinal ridges of a martian landslide and show that the wavelength of the ridges is 2–3 times the average thickness of the landslide deposit, a unique scaling relationship previously reported in ice-free rapid granular flow experiments. We recognize en-echelon features that we interpret as kinematic indicators, congruent with experimentally-measured transverse velocity gradient. We suggest that longitudinal ridges should not be considered as unequivocal evidence for presence of ice, rather as inevitable features of rapid granular sliding material, that originate from a mechanical instability once a kinematic threshold is surpassed. |
format | Online Article Text |
id | pubmed-6813353 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-68133532019-10-28 Longitudinal ridges imparted by high-speed granular flow mechanisms in martian landslides Magnarini, Giulia Mitchell, Thomas M. Grindrod, Peter M. Goren, Liran Schmitt, Harrison H. Nat Commun Article The presence of longitudinal ridges documented in long runout landslides across our solar system is commonly associated with the existence of a basal layer of ice. However, their development, the link between their occurrence and the emplacement mechanisms of long runout landslides, and the necessity of a basal ice layer remain poorly understood. Here, we analyse the morphometry of longitudinal ridges of a martian landslide and show that the wavelength of the ridges is 2–3 times the average thickness of the landslide deposit, a unique scaling relationship previously reported in ice-free rapid granular flow experiments. We recognize en-echelon features that we interpret as kinematic indicators, congruent with experimentally-measured transverse velocity gradient. We suggest that longitudinal ridges should not be considered as unequivocal evidence for presence of ice, rather as inevitable features of rapid granular sliding material, that originate from a mechanical instability once a kinematic threshold is surpassed. Nature Publishing Group UK 2019-10-24 /pmc/articles/PMC6813353/ /pubmed/31649236 http://dx.doi.org/10.1038/s41467-019-12734-0 Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Magnarini, Giulia Mitchell, Thomas M. Grindrod, Peter M. Goren, Liran Schmitt, Harrison H. Longitudinal ridges imparted by high-speed granular flow mechanisms in martian landslides |
title | Longitudinal ridges imparted by high-speed granular flow mechanisms in martian landslides |
title_full | Longitudinal ridges imparted by high-speed granular flow mechanisms in martian landslides |
title_fullStr | Longitudinal ridges imparted by high-speed granular flow mechanisms in martian landslides |
title_full_unstemmed | Longitudinal ridges imparted by high-speed granular flow mechanisms in martian landslides |
title_short | Longitudinal ridges imparted by high-speed granular flow mechanisms in martian landslides |
title_sort | longitudinal ridges imparted by high-speed granular flow mechanisms in martian landslides |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6813353/ https://www.ncbi.nlm.nih.gov/pubmed/31649236 http://dx.doi.org/10.1038/s41467-019-12734-0 |
work_keys_str_mv | AT magnarinigiulia longitudinalridgesimpartedbyhighspeedgranularflowmechanismsinmartianlandslides AT mitchellthomasm longitudinalridgesimpartedbyhighspeedgranularflowmechanismsinmartianlandslides AT grindrodpeterm longitudinalridgesimpartedbyhighspeedgranularflowmechanismsinmartianlandslides AT gorenliran longitudinalridgesimpartedbyhighspeedgranularflowmechanismsinmartianlandslides AT schmittharrisonh longitudinalridgesimpartedbyhighspeedgranularflowmechanismsinmartianlandslides |