Geomorphology characterization of Ica basin and its influence on the dynamic response of soils for urban seismic hazards in Ica, Peru

• Autores: Bernal Esquia, Yesenia Isabel, Tavera, Hernando, Sulla Huillca, Wilfredo, Arredondo García, Luz Mercedes, Oyola, Javier
• Formato: artículo
• Fecha de Publicación: 2018
• Institución: Instituto Geofísico del Perú
• Repositorio: IGP-Institucional
• Lenguaje: inglés
• OAI Identifier: oai:repositorio.igp.gob.pe:20.500.12816/2285
• Enlace del recurso: http://hdl.handle.net/20.500.12816/2285; https://doi.org/10.1155/2018/9434251
• Nivel de acceso: acceso abierto
• Materia: Geomorphology; Geology; Geologic engineering; Seismic risk; Earthquake engineering; http://purl.org/pe-repo/ocde/ford#1.05.00; http://purl.org/pe-repo/ocde/ford#1.05.04; http://purl.org/pe-repo/ocde/ford#1.05.06; http://purl.org/pe-repo/ocde/ford#2.07.01

We evaluated the influence of the geomorphology of Peru’s Ica Basin on the dynamic response of soils of the city of Ica. We applied five geophysical methods: spectral ratio (H/V), frequency-wavenumber (F-J), multichannel analysis of surface waves (MASW), multichannel analysis of microtremor (MAM), and Gravimetric Analysis. Our results indicate that the soils respond to two frequency ranges: FO (0.4–0.8 Hz) and F1 (1.0–3.0 Hz). The F-K, which considers circular arrays, shows two tendencies with a jump between 1.0 and 2.0 Hz. MASW and MAM contribute to frequencies greater than 2.0 Hz. The inversion curve indicates the presence of three layers of 4, 16, and 60 m with velocities of 180, 250, and 400 m/s. The Bouguer anomalies vary between −17.72 and −24.32 mGal and with the spectral analysis we identified two deposits, of 60 m and 150 m of thickness. Likewise, the relationship between the velocities of 400 and 900 m/s, with the frequency = 1.5 Hz, allows us to determine the thickness for the layers of 60 (slightly alluvial to moderately compact) and 150 m (soil-rock interface). These results suggest that the morphology of the Ica Basin plays an important role in the dynamic behavior of the soils to low frequency.