Forensic Geology Applied to Decipher the Landslide Dam Collapse and Outburst Flood of the Santa Cruz River (12 November 2005), San Juan, Argentina
A well-known landslide dam that collapsed and generated a large outburst flood is used to show the importance of forensic geology analysis, which is the on-site multidisciplinary study of geohazards carries out as soon as possible after their occurrence; this study is focused on understanding the co...
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ftmdpi:oai:mdpi.com:/2624-795X/3/2/14/ 2023-08-20T04:07:09+02:00 Forensic Geology Applied to Decipher the Landslide Dam Collapse and Outburst Flood of the Santa Cruz River (12 November 2005), San Juan, Argentina Juan Pablo Milana Philipp Geisler agris 2022-05-12 application/pdf https://doi.org/10.3390/geohazards3020014 EN eng Multidisciplinary Digital Publishing Institute https://dx.doi.org/10.3390/geohazards3020014 https://creativecommons.org/licenses/by/4.0/ GeoHazards; Volume 3; Issue 2; Pages: 252-276 jökulhlaup natural dam landslide avalanche governance Text 2022 ftmdpi https://doi.org/10.3390/geohazards3020014 2023-08-01T05:01:36Z A well-known landslide dam that collapsed and generated a large outburst flood is used to show the importance of forensic geology analysis, which is the on-site multidisciplinary study of geohazards carries out as soon as possible after their occurrence; this study is focused on understanding the complete spectrum of all mechanisms that caused the disaster. Diagnostic elements of all natural processes fade with time, allowing for progressively divergent interpretations that may impact the appropriateness of potential mitigation actions, as we demonstrate. The multidisciplinary field control of the abrupt rupture of a natural dam on the Santa Cruz River on 12 November 2005, that released c. 37 million m3 of water and sediment, can radically change the interpretation of how this dam collapsed. In situ sedimentological, geomorphological and topographical analyses of the remains of the collapsed natural dam suggest it was built in two mass-wasting episodes instead of one, as previously interpreted, involving different slide materials. The first episode matches previous interpretations; a landslide that evolved into a rock avalanche, generating an initial dam of high stability due to its density, and observed angles of repose. This dam was not removed completely during the rupture, but rather suffered minor erosion at its top by the flood drag effect. The second episode is interpreted as a snow-dominated mixed avalanche, reaching much greater heights on the opposite side of the valley. This avalanche is estimated to be 85% snow, 8% debris and 7% ice-cemented permafrost fragments, and is evidenced by a thin residual deposit draping the valley sides, as most of this deposit melted out before any field control was undertaken. The growth of the lake level, along with the dam weight loss due to ablation, generated the hydrostatic instability that caused the floating of the central sector of this second dam and the violent evacuation of the water, similar to a jökulhlaup. This analysis explains the partial dam collapse, ... Text Ice permafrost MDPI Open Access Publishing Argentina San Juan GeoHazards 3 2 252 276 |
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Open Polar |
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MDPI Open Access Publishing |
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English |
topic |
jökulhlaup natural dam landslide avalanche governance |
spellingShingle |
jökulhlaup natural dam landslide avalanche governance Juan Pablo Milana Philipp Geisler Forensic Geology Applied to Decipher the Landslide Dam Collapse and Outburst Flood of the Santa Cruz River (12 November 2005), San Juan, Argentina |
topic_facet |
jökulhlaup natural dam landslide avalanche governance |
description |
A well-known landslide dam that collapsed and generated a large outburst flood is used to show the importance of forensic geology analysis, which is the on-site multidisciplinary study of geohazards carries out as soon as possible after their occurrence; this study is focused on understanding the complete spectrum of all mechanisms that caused the disaster. Diagnostic elements of all natural processes fade with time, allowing for progressively divergent interpretations that may impact the appropriateness of potential mitigation actions, as we demonstrate. The multidisciplinary field control of the abrupt rupture of a natural dam on the Santa Cruz River on 12 November 2005, that released c. 37 million m3 of water and sediment, can radically change the interpretation of how this dam collapsed. In situ sedimentological, geomorphological and topographical analyses of the remains of the collapsed natural dam suggest it was built in two mass-wasting episodes instead of one, as previously interpreted, involving different slide materials. The first episode matches previous interpretations; a landslide that evolved into a rock avalanche, generating an initial dam of high stability due to its density, and observed angles of repose. This dam was not removed completely during the rupture, but rather suffered minor erosion at its top by the flood drag effect. The second episode is interpreted as a snow-dominated mixed avalanche, reaching much greater heights on the opposite side of the valley. This avalanche is estimated to be 85% snow, 8% debris and 7% ice-cemented permafrost fragments, and is evidenced by a thin residual deposit draping the valley sides, as most of this deposit melted out before any field control was undertaken. The growth of the lake level, along with the dam weight loss due to ablation, generated the hydrostatic instability that caused the floating of the central sector of this second dam and the violent evacuation of the water, similar to a jökulhlaup. This analysis explains the partial dam collapse, ... |
format |
Text |
author |
Juan Pablo Milana Philipp Geisler |
author_facet |
Juan Pablo Milana Philipp Geisler |
author_sort |
Juan Pablo Milana |
title |
Forensic Geology Applied to Decipher the Landslide Dam Collapse and Outburst Flood of the Santa Cruz River (12 November 2005), San Juan, Argentina |
title_short |
Forensic Geology Applied to Decipher the Landslide Dam Collapse and Outburst Flood of the Santa Cruz River (12 November 2005), San Juan, Argentina |
title_full |
Forensic Geology Applied to Decipher the Landslide Dam Collapse and Outburst Flood of the Santa Cruz River (12 November 2005), San Juan, Argentina |
title_fullStr |
Forensic Geology Applied to Decipher the Landslide Dam Collapse and Outburst Flood of the Santa Cruz River (12 November 2005), San Juan, Argentina |
title_full_unstemmed |
Forensic Geology Applied to Decipher the Landslide Dam Collapse and Outburst Flood of the Santa Cruz River (12 November 2005), San Juan, Argentina |
title_sort |
forensic geology applied to decipher the landslide dam collapse and outburst flood of the santa cruz river (12 november 2005), san juan, argentina |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2022 |
url |
https://doi.org/10.3390/geohazards3020014 |
op_coverage |
agris |
geographic |
Argentina San Juan |
geographic_facet |
Argentina San Juan |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
GeoHazards; Volume 3; Issue 2; Pages: 252-276 |
op_relation |
https://dx.doi.org/10.3390/geohazards3020014 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/geohazards3020014 |
container_title |
GeoHazards |
container_volume |
3 |
container_issue |
2 |
container_start_page |
252 |
op_container_end_page |
276 |
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1774718611218235392 |