Subaequeous landslides analysis in lacustrine deltas (Nahuel Huapi lake, Argentina) through high-resolution bathymetry

Authors

  • D. Beigt Instituto de Investigaciones en Biodiversidad y Medioambiente (CONICET/UNCo), Quintral 1250, San Carlos de Bariloche (CP 8400), Río Negro, Argentina
  • G. Villarosa Instituto de Investigaciones en Biodiversidad y Medioambiente (CONICET/UNCo), Quintral 1250, San Carlos de Bariloche (CP 8400), Río Negro, Argentina
  • E.A. Gómez Instituto Argentino de Oceanografía (CONICET/UNS), Camino La Carrindanga km 7, Bahía Blanca (CP 8000), Buenos Aires

DOI:

https://doi.org/10.18172/cig.2472

Keywords:

Nahuel Huapi lake, mass-wasting events, subaequeous landslides, lacustrine deltas, 1960 tsunami

Abstract

The cities located along the coasts of the North-Patagonian Andean lakes are exposed to regional seismic and volcanic activities and associated tsunamigenic events developed in the lacustrine basins. Extraordinary waves, such as the 1960 tsunami in Nahuel Huapi lake that hit the coasts of the city of Bariloche, may be induced by subaequeous or subaerial landslides triggered during a strong earthquake (Villarosa et al., 2009). This article focusses on the study of mass-wasting processes that occur in the submerged portion of lacustrine deltas located at the coasts of Bariloche and Dina Huapi cities. The results presented here are an input for future hazard evaluation studies. The subaequeous morphology was surveyed using a Phase Measuring Bathymetric Sonar System. Digital Elevation Models and DEMderived maps were performed in ArcGIS. Bathymetric data show characteristic features of Gilbert-type deltas: steep delta fronts where sediments are mobilized by gravitational processes (landslides, debris flows and/or turbidity currents). Numerous landslides found in the delta fronts (~10-m high headscarps with a maximum length of ~200 m, and lateral scarps that exceed a length of 600 m) indicate that mass-wasting phenomena involving large volumes of sediment periodically develop in these environments. These events are potential generators of waves in the water surface. The proximity among these deltas and the coastal cities implies that an event of this kind triggered by a strong regional earthquake could affect their vulnerable coasts.

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Author Biographies

D. Beigt, Instituto de Investigaciones en Biodiversidad y Medioambiente (CONICET/UNCo), Quintral 1250, San Carlos de Bariloche (CP 8400), Río Negro, Argentina

Grupo de Estudios Ambientales

Investigadora Asistente CONICET

G. Villarosa, Instituto de Investigaciones en Biodiversidad y Medioambiente (CONICET/UNCo), Quintral 1250, San Carlos de Bariloche (CP 8400), Río Negro, Argentina

Grupo de Estudios Ambientales

Investigador Adjunto CONICET

E.A. Gómez, Instituto Argentino de Oceanografía (CONICET/UNS), Camino La Carrindanga km 7, Bahía Blanca (CP 8000), Buenos Aires

Oceanografía Física

Investigador Indepediente CONICET

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Published

06-03-2014

How to Cite

1.
Beigt D, Villarosa G, Gómez E. Subaequeous landslides analysis in lacustrine deltas (Nahuel Huapi lake, Argentina) through high-resolution bathymetry. CIG [Internet]. 2014 Mar. 6 [cited 2024 Mar. 29];40(1):247-60. Available from: https://publicaciones.unirioja.es/ojs/index.php/cig/article/view/2472