Seismic activity beneath the Iglesia Valley between the Andean Frontal Cordillera and the northern Precordillera, Argentina

ORTIZ, G.; ALVARADO, P.; RIVAS, C.; PODESTA, M.; PEREZ, I.; SAEZ, M.

Quito

Congreso; 8th International Symposium on Andean Geodynamics (ISAG); 2019

International Symposium on Andean Geodynamics (ISAG)

In this work we analyze the seismicity of the northern Precordillera of Argentina lying above the flat slab subduction of the Nazca plate beneath South America. This region of about 110 km by 280 km is located between the Frontal Andean Cordillera and the western thin-skinned Precordillera fold and thrust belt. The same region has been the epicentral area of the 1894 damaging earthquake (Bodenbender, 1894), which caused maximum Modified Mercalli intensities of IX. Although, little is known of its seismic source because of the unavailability of instrumental records at that time, it is possible to characterize present earthquake deformation. In this work we integrate seismic records from permanent (e.g. INPRES) and temporary stations (e.g. CHARGE and SIEMBRA experiments) to analyze crustal seismicity. We obtain seismic location (focal depth, with a concentration range between 10 and 30 km), magnitude (1.2