Resumen

LEYTON, Felipe; MONTALVA, Gonzalo  y  RAMIREZ, Paola. A preliminary study of seismic microzonation of Concepción based on microtremors, geology and damages patterns. Obras y Proyectos [online]. 2012, n.11, pp. 40-46. ISSN 0718-2813.  doi: 10.4067/S0718-28132012000100004.

We perform microtremors measurements at Concepción and compute the predominantfrequency using horizontal-to-vertical spectral ratio (HVSR). We compare these results with the surface geology and several geotechnical surveys existing in the region, enabling a general characterization of the area. We present and complement these results with observations of damage produced by the M_w 8.8 Maule 2010 earthquake. Preliminary results show the presence of fine-grained materials in the area characterized by very low predominant frequency (lower than 1.5 Hz), which might explain the extensive damage observed at Concepción and surroundings.

Palabras clave : seismic microzonation; Concepción geology; microtremors' HVSR.