Modelo de velocidades sísmicas de Cuba Oriental

Abstract

This study determines a one-dimensional seismic velocity model to be used in the daily routine analysis of earthquake data. This is useful for the geographical localization of the seismic events as well as an initial model for 3D seismic tomography studies. In order to calculate the velocity model, the Cuban earthquake catalogue from 1998 until the 2004 was used. The chosen area for the study is located in the eastern part of the Cuban Island, specifically between 19.80-21.00 north latitude and 74.33-77.00 west longitude. From a total of 209 local events, 117 events with RMS between 0 and 1 seconds, GAP between 0-180° and recorded for 3 or more stations were selected. The obtained velocity model has mainly three layers. A shallow layer 1 km-thick and P-wave velocity of 3.6 km/s, an intermediate layer 6 km-thick and P-wave velocity of 5.8 km/s and a bottom layer 13 km-thick and P-wave velocity of 6.9 km/s. The results suggest a transitional crust with an average thickness of 20 km.

Crustal structure of eastern Cuba, derived by constrained 3D gravity inversion

“…Otero et al (1998) based on re-interpreted seismic and gravity data proposed that the crust southward of Cauto-Nipe (Figure 1) is oceanic, ~20 km thickness, and below the basin there is a fine-transitional crust with 20 to 30 km thick and northward continental crust. Through teleseismic data, Palau et al (2006) determined the presence of a 1 km thick shallow layer with P velocity of 3.6 km/s, underneath a 6 km thick layer with P of 5.8 km/s and a deeper 13 km thick layer with 6.9 km/s for P. Recently, Gonzalez et al (2011) defined a 16 to 30 km earth crust thickness for eastern Cuba, through joint inversion of Rayleigh waves dispersion and receptor functions. All these models are assumed onedimensional or horizontal stratified.…”

Nuevo catálogo macrosísmico de terremotos perceptibles en Cuba 2017 – 2020

“…Estos dos parámetros son muy importantes para el cálculo del campo macrosísmico y en ellos influye directamente la calidad de la detección de los sismos, específicamente los parámetros hipocentrales del foco. Los que se garantizan con alta precisión al contar con modelos de velocidades propios para la región (Moreno, Grandison, Atakan, 2002;Palau, Moreno y Blanco, 2006), un umbral de detección efectiva de la red sismológica (cualquier sismo de una Mw ≥ 3 puede ser registrado por al menos tres estaciones) (Palau et al, 2018) y la determinación de la magnitud por momento (Mw) como rutina para todos los eventos, lo que facilita el trabajo con el catálogo cubano en cuanto a estudios de peligrosidad sísmica (Villalón y Palau, 2018).…”