Ref: POSTER-2022-0033

On the Jujuy intermediate-deep seismic Nest, Chile-Argentina border

Valenzuela Malebran, Carla ; Cesca, Simone ; Lopez-Comino, Jose-Angel ; Zeckra, Martin ; Fernandez, Gonzalo ; Krüger, Frank ; Dahm, Torsten

Poster presented at AGU Fall Meeting 2021, New Orleans on 2021-12-16

Abstract: In Central Andes, the convergence of the oceanic Nazca Plate beneath the continental South American Plate, led to the formation of the Altiplano-Puna plateau, the second-largest continental plateau on Earth. The Puna plateau is 4 km high with a Moho depth of 50 km. A large seismicity cluster is observed at a depth of 200 km in the central region of the Puna plateau. This deeper band of intraplate seismicity is locally clustered and is extending North to South, parallel to the trench. It has been hypothesized that this large cluster could be a seismic nest, a compact seismogenic region characterized by a high stationary activity relative to its surroundings. We collected more than 40 years of data from different catalogs and show that the seismicity in the region (Lat -21° to -25° and Lon -68° to -65°) meets the conditions of a seismic nest. The spatial and temporal seismicity patterns of the plateau are compared to other known nests with the same or different tectonic settings. In addition, due to the availability of a large dataset between 2017-2018, we perform a detailed analysis on the large seismic sources. We use hypocentral locations, inversion of the moment tensor, finite source analysis and directivity to deduce most from the large events during the period. Our analysis shows, most events appear to occur in the oceanic plate and show vertical and horizontal rupture planes.

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The record appears in these collections:
Royal Observatory of Belgium > Seismology & Gravimetry
Conference Contributions & Seminars > Posters

 Record created 2022-06-20, last modified 2022-06-20