Age constraints and paleoseismic implication of rock avalanches in the northern Patagonian Andes, Argentina

Landslides and rock avalanches are far more common features than once believed in the glacial valleys of the northern Patagonian Andes of Argentina. We describe three rock avalanches located in northwestern Neuquén province that generated landslide-dammed lakes. Cosmogenic radionuclide 36Cl dating c...

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Autores principales: Costa, C.H., Díaz, E.F.G.
Formato: JOUR
Materias:
Landslide-dammed lakes
Neuquén
Paleoseismicity
Rock avalanches
cosmogenic radionuclide
earthquake
flood
landslide
outburst
paleoseismicity
Pleistocene
rock avalanche
valley glacier
Argentina
Neuquen
South America
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_08959811_v24_n1_p48_Costa
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_08959811_v24_n1_p48_Costa
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spelling todo:paper_08959811_v24_n1_p48_Costa2023-10-03T15:42:44Z Age constraints and paleoseismic implication of rock avalanches in the northern Patagonian Andes, Argentina Costa, C.H. Díaz, E.F.G. Landslide-dammed lakes Neuquén Paleoseismicity Rock avalanches cosmogenic radionuclide earthquake flood landslide outburst paleoseismicity Pleistocene rock avalanche valley glacier Argentina Neuquen South America Landslides and rock avalanches are far more common features than once believed in the glacial valleys of the northern Patagonian Andes of Argentina. We describe three rock avalanches located in northwestern Neuquén province that generated landslide-dammed lakes. Cosmogenic radionuclide 36Cl dating constrains their average ages as Late Pleistocene for the Lagunas de Varvarco rock avalanches (79.0 ± 3.0-63.0 ± 3.0 ka and 37.0 ± 1.8-29.0 ± 1.5 ka) and Holocene (2.2 ± 0.6 ka) for the Barrancas avalanche. The landslide dam originated by the Barrancas rock avalanche became unstable on December 29, 1914, causing a devastating outburst flood. These phenomena indicate rock volumes greater than 5 × 105 m3 each, and the Varvarco Campos rock avalanche (3.51 × 109 m3) is the largest rock avalanche recognized in Argentina. The rock avalanches described here occurred after the glacial retreat. The volume of the landslides and the matching of these gravitational phenomena with current seismicity data, as well as other morphometric, lithologic, and structural characteristics, suggest that these rock avalanches likely were triggered by earthquakes. On the basis of empirical relations, we postulate that the Varvarco Campos rock avalanche testifies to a paleoearthquake of magnitude (M > 8), much larger than the events recorded by instrumental seismicity (M ≤ 5.8). © 2007 Elsevier Ltd. All rights reserved. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_08959811_v24_n1_p48_Costa
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Landslide-dammed lakes
Neuquén
Paleoseismicity
Rock avalanches
cosmogenic radionuclide
earthquake
flood
landslide
outburst
paleoseismicity
Pleistocene
rock avalanche
valley glacier
Argentina
Neuquen
South America
spellingShingle Landslide-dammed lakes
Neuquén
Paleoseismicity
Rock avalanches
cosmogenic radionuclide
earthquake
flood
landslide
outburst
paleoseismicity
Pleistocene
rock avalanche
valley glacier
Argentina
Neuquen
South America
Costa, C.H.
Díaz, E.F.G.
Age constraints and paleoseismic implication of rock avalanches in the northern Patagonian Andes, Argentina
topic_facet Landslide-dammed lakes
Neuquén
Paleoseismicity
Rock avalanches
cosmogenic radionuclide
earthquake
flood
landslide
outburst
paleoseismicity
Pleistocene
rock avalanche
valley glacier
Argentina
Neuquen
South America
description Landslides and rock avalanches are far more common features than once believed in the glacial valleys of the northern Patagonian Andes of Argentina. We describe three rock avalanches located in northwestern Neuquén province that generated landslide-dammed lakes. Cosmogenic radionuclide 36Cl dating constrains their average ages as Late Pleistocene for the Lagunas de Varvarco rock avalanches (79.0 ± 3.0-63.0 ± 3.0 ka and 37.0 ± 1.8-29.0 ± 1.5 ka) and Holocene (2.2 ± 0.6 ka) for the Barrancas avalanche. The landslide dam originated by the Barrancas rock avalanche became unstable on December 29, 1914, causing a devastating outburst flood. These phenomena indicate rock volumes greater than 5 × 105 m3 each, and the Varvarco Campos rock avalanche (3.51 × 109 m3) is the largest rock avalanche recognized in Argentina. The rock avalanches described here occurred after the glacial retreat. The volume of the landslides and the matching of these gravitational phenomena with current seismicity data, as well as other morphometric, lithologic, and structural characteristics, suggest that these rock avalanches likely were triggered by earthquakes. On the basis of empirical relations, we postulate that the Varvarco Campos rock avalanche testifies to a paleoearthquake of magnitude (M > 8), much larger than the events recorded by instrumental seismicity (M ≤ 5.8). © 2007 Elsevier Ltd. All rights reserved.
format JOUR
author Costa, C.H.
Díaz, E.F.G.
author_facet Costa, C.H.
Díaz, E.F.G.
author_sort Costa, C.H.
title Age constraints and paleoseismic implication of rock avalanches in the northern Patagonian Andes, Argentina
title_short Age constraints and paleoseismic implication of rock avalanches in the northern Patagonian Andes, Argentina
title_full Age constraints and paleoseismic implication of rock avalanches in the northern Patagonian Andes, Argentina
title_fullStr Age constraints and paleoseismic implication of rock avalanches in the northern Patagonian Andes, Argentina
title_full_unstemmed Age constraints and paleoseismic implication of rock avalanches in the northern Patagonian Andes, Argentina
title_sort age constraints and paleoseismic implication of rock avalanches in the northern patagonian andes, argentina
url http://hdl.handle.net/20.500.12110/paper_08959811_v24_n1_p48_Costa
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