Intraplate seismicity recorded by a local network in the Neuquén Basin, Argentina

Abstract

Intraplate seismicity in the Southern Central Andes has been mostly documented to the north of 35°S, while similar phenomenon south of these latitudes is not known so far. In order to contribute to this issue, we analysed seismicity in the Andean back-arc region between 38°S and 39°S through a seismological experiment using a local broadband seismic network in the Neuquén Basin. In this study, we aim to determine the background (base) seismicity of the region, and integrate the results with gravimetric data and previous geological knowledge to identify potential sources of the seismic activity. In addition to low-grade seismicity we recorded a Ml = 3.78 strike-slip earthquake ∼ 100 km west of Neuquén city on November 19, 2015. Seismicity location could be controlled by thermo-mechanical properties of the lithosphere linked to the previous tectonic evolution. On the other hand, the triggering factor could be related to E-W Andean stress-field or to human-induced activity.