Abstract

SABBIONE, Juan I; ROSA, María Laura; VELIS, Danilo R  and  SABBIONE, Nora C. Análisis comparativo de diferentes métodos de picado automático de fases en terremotos registrados en la Estación Sismológica de La Plata (LPA). Geoacta [online]. 2011, vol.36, n.2, pp.189-209. ISSN 1852-7744.

We analyzed eight methods of detection and automatic body phase picking. Three of them are conventional methods, two are new methods developed from improvements to conventional methods, and the other three are methods originally designed for first-break picking of seismic exploration data. To analyze the methods, we selected eleven one-hour records obtained at La Plata Seismological Station (LPA) corresponding to regional and teleseismic earthquakes with magnitudes greater than 6 (Mw) and diverse epicentral distances and focus depths. The records were previously manually picked by an analyst. We attempted to pick a total of 30 phases automatically, 25 of which had originally been observed by the analyst. The other 5 phases, were identified from the application of the automatic methods, and then corroborated by using the IASP91 model. The efficiency of the methods was studied based on the detection percentage obtained and the false phase percentage generated. The picking errors were also analyzed from a statistical point of view in order to estimate the accuracy and precision of the proposed methods. This analysis allowed us to make a relative assessment of the eight automatic picking methods proposed. The results show that some of the methods exhibit significant advantages over the others. These methods that show better performance would be appropriate to systematically carry out the automatic picking, both for global seismology studies and seismicity studies, especially when a large volume of data is available.

Keywords : Event detection; Earthquake phases; Automatic picking; False alarms.

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