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Departamento de Geografía, Universidad del Valle, Cali, Colombia
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- PublicationOpen AccessAnalisis complementario entre parametros instrumentales y macrosismicos: terremoto de mayo 24, 2008 en Quetame, ColombiaThe earthquake of May 24th, 2008, occurred in the municipality of Quetame (Colombia), is a recent event detected by the RSNC and the World Seismological Network, which reported their seismological parameters: epicenter, depth, magnitude, scalar seismic moment and focal mechanism, among others. Based on the damages and effects caused, INGEOMINAS (Colombian Geological Survey) evaluated the macroseismic field, preparing the map of intensities with data in various populations of the departments of Cundinamarca, Tolima and Meta, mainly. Based on this macroseismic information, in this work some macroseismic analysis methods are applied to obtain the corresponding focal parameters. The results show strong correlations or similarities between instrumental and macroseismic parameters. Instrumentally reported: Epicenter 4.4°N and 73.81°W; h=14.7 km, 5.9 Mw, 5.9 Ms, 5.6 mb, 5.7 ML; M0=7.95*1024 dynes-cm. While macroseismically it was obtained: Epicenter 4.34°N and 73.86°W; 5.94 Mw, 5.5 Ms, 5.6±0.2 mb, 5.63 ML; hn=12.1 km, hl=2.23 km; E=4.57*1020 erg, M0=9.14*1024 dynes-cm; the parameters of the dimensions of the seismic focus and the seismotectonic deformation expressed by the seismic flow of the rock mass were also determined. The applied procedures show the character of complementarity between instrumental and macroseismic data.
372 18 - PublicationRestrictedEstudio macrosismico del terremoto del 18 octubre del 1743 en la region central de Colombia(2013-06)
; ; ;Salcedo-Hurtado, E.; Universidad del Valle (Cali, Colombia) ;Gomez Capera, A. A,; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; On October 18, 1743 a great earthquake hit in Colombian central region. This seismic event caused severe damage in Santa Fe de Bogota that since 1740 had just been reinstated again as the capital of the “Nuevo Reino de Granada”. The churches of “Monserrate” and “Guadalupe” were destroyed and other suffered heavy damage. Damages were extended in surrounding areas as the towns of Fómeque, Chia, Usaquén Cáqueza, among others. In these towns, the churches were destroyed, and subsidence phenomena were noted, large cracks, fissures and landslides that clogged roads and some rivers and caused the death several people and animals. Applying the 1998 European Macroseismic Scale (EMS- 98), in the present work reassessing the macroseismic intensity in each affected town. We present a new macroseismic map with 18 intensity data points. We have proposed as maximum intensity equal to VIII in Fómeque, Guachavita and Cáqueza. In Santa Fe de Bogota the instensity is VII. The Bakun and Wentworth (1997) method is applied, using the intensity data points obtained in the present study and macroseismic intensity attenuation relationship given by Gómez Capera and Salcedo Hurtado (2002), to estimate earthquake parameters to 1743 event. We have proposed a macroseismic magnitude that equals 6.30±0.35 and the epicenter location in (4.43N, 73.91W) between the townships of Cáqueza and Guachavita.595 32 - PublicationRestrictedInventario de Daños y Efectos Geológicos Co y/o Post-Sísmicos del Sismo Ocurrido el 18 de mayo de 1875, en la Frontera entre Colombia y Venezuela(2015-09)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; On the border between Colombia and Venezuela, have occurred seismic events with important records of damage in both countries. In this paper, we study the historical earthquake that took place on May 18, 1875 between 11.15 and 11.30 in the morning (the time was the same for communities in both countries since there was no time zone difference), which is catalogued as a border earthquake due to the report of damages in the cities of both nations. The community of San José de Cúcuta, current capital of the Northern State of Santander, Colombia, registered the greatest number of deaths and damage to buildings. An inventory of the geological damage and co -seismic and postseismic effects was created based on information of previous studies and data obtained from archival primary sources from Colombia and Venezuela. The result is a bi-national database, which includes the summaries of historical descriptions with the effects in the persons and objects, the geological damages and effects observed during the seismic event. These data has led to the creation of a table of MM and EMS-98 intensities, which enables the identification and delimitation of the regions of greater damages. The maximum level intensity is I=10 in the cities of San José de Cúcuta, Villa del Rosario, Pueblo de Cúcuta (San Luis) in Colombia and San Antonio, San Juan de Ureña in Venezuela. Moreover, we formulated a table of intensities using the ESI-2007 INQUA scale, based on the information of geological observations described in historical documents. These data are related to the epicentral zone with an approximate radius of 30 km.614 8 - PublicationOpen AccessSismicidad y sismotectónica para el sector norte del ámbito del Sistema de Fallas de Algeciras, Cordillera Oriental, ColombiaAl Sistema de Fallas de Algeciras (SFA), se le han asignado cuatro sismos históricos desde finales del siglo XVIII, que en términos de magnitud recalculada desde análisis macrosísmicos tuvieron una magnitud M>6.5. Uno de estos, el del 9 de febrero de 1967, fue registrado instrumentalmente con Mw 7.2. En este trabajo se realizó un estudio del sector norte de este sistema de fallas entre los 3° y 4°N. Entre el 31 de octubre de 2016 y el 18 de julio de 2018, se presentaron cuatro sismos con Mw>4.8, que la Red Sismológica Nacional de Colombia (RSNC) localizó en el municipio de Colombia, departamento del Huila, asignándolos a fallas del SFA. Luego, en diciembre 24 de 2019, se presentó un sismo con Mw 6.0, que se asignó a la Falla Algeciras perteneciente al SFA en el departamento del Meta. En esta investigación se encontró que los sismos de la región de Colombia se produjeron en las fallas Altamira y Nazareth, las cuales son fallas inversas en un contexto tectono - estratigráfico diferente al SFA. El SFA al norte de los 3°N define en esta región el piedemonte llanero. Para las fallas Altamira y Nazareth, los mecanismos focales indicaron fallas inversas, mientras que en la región de Mesetas estos mecanismos obedecieron a fallas transcurrentes concordantes con el SFA. Dada la alta generación de sismos con Mw>5.0 en estas fallas en un lapso inferior a 10 años, se establece que su potencial sismogénico contribuye de manera importante a la amenaza sísmica del centro y el suroccidente de Colombia, sin embargo, en este trabajo se encontró además que la denominada Falla Algeciras, principal componente del SFA por la literatura, está segmentada y no es continua, por lo que se debe revaluar su potencial sismogénico
360 14 - PublicationOpen AccessLocalización y magnitud del terremoto de 1785 en Colombia calculadas a partir de intensidades macrosísmicasThe earthquake that hit Colombia on July 12, 1785, is one of the seismic events with the highest number of macroseismic studies based on historical sources. Most of these studies have assigned a maximum intensity of VIII to the event. Following the study of Salcedo Hurtado and Castaño Castaño (2011), and applying the Bakun and Wentworth (1997) method and the macroseismic intensity attenuation proposed by Gómez Capera and Salcedo Hurtado (2002), we calculated the magnitude m b = 6.9±0.2 and the macroseismic epicentre at 28 km from Bogotá. The validation of the attenuation model was performed with the instrumental parameters of the earthquake occurred on May 24, 2008, in the same region of the historical earthquake studied in the present article.
548 44 - PublicationOpen AccessCalibración y validación del algoritmo de Bakun and Wentworth para calcular localización y magnitud de Terremotos históricos a partir de datos macrosísmicos en Cuba orienTal(2013)
; ; ; ; ; ; ; ; ;We present the results of a calibration analysis performed on eastern Cuba seismicity datasets of the approach proposed by Bakun and Wentworth (1997) to bound earthquakes epicentral area and magnitude from MSK macroseismic data only. The calibration is required as the algorithm derives an intensity magnitude (equal in the mean to moment magnitude Mw) from macroseismic observations by using a regionally suitable attenuation relationship of intensity as a function of Mw and source distance. To this purpose, a training set of 8 Post-900 earthquakes occurred in eastern Cuba was selected, for which a large number of intensity observations and reliable instrumental determinations of Mw and epicentral location are available. The model is given by: I =(3.11±0.40)+(1.40±0.09)*Mw-(0.0017±0.00027)*R-(3.17±0.20)*LogR MSK where R is the hypocentral distance in kilometres, the model is calibrated for earthquakes in the range of 5.22≥Mw≥6.81, hypocentral distances less than 400km and fixed depth at 10km. The model is validated using the 1947, 1976 and 1998 earthquakes, which were not used in the calibration process and also have instrumental data. The validation of the algorithm demonstrates reliability and applicability of the method for the analysis of historical earthquakes that have no records of instrumental parameters. An overall agreement is found for both the location and magnitude of these events with magnitude uncertainties between 0.23 and 0.35 equivalent to two standard deviations. However the MDPs distributions are partially azimuthal for those 11 analyzed earthquakes, the model can reproduce offshore epicentres within acceptable uncertainties ranges. A first application is made to a historical earthquake occurred on June 6, 1766 causing severe damage to the city of Santiago de Cuba.519 33 - PublicationOpen AccessState-of-the-art of the historical seismology in Colombia(2004)
; ; ; ;Espinosa Baquero, A.; Facultad de Ingeniería, Universidad del Quindío, Armenia, Colombia ;Capera, A. A. G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia ;Salcedo Hurtado, E. J.; Departamento de Geografía, Universidad del Valle, Cali, Colombia; ; In Colombia are available a discreet number of historical seismology investigations, dating back 50 years. This paper reviews basic information about earthquakes studies in Colombia, such as primary sources, compilation of descriptive catalogues and parametric catalogues. Father Jesús Emilio Ramírez made the main systematic study before 1975. During the last 20 years, great earthquakes hit Colombia and, as consequence, historical seismology investigation was developed in the frame of seismic hazard projects.250 4059 - PublicationOpen AccessEstimating Magnitude and Location from macroseimic data of the 1925 Colombian earthquake(2022-06-23)
; ; ; ; ; ; ; ; ; The earthquake of 7 June 1925, which occurred in south-western Colombia, is one of the most important intraplate seismic events in the region. This earthquake caused damage at several localities along the Cauca valley. The distribution of the intensity data points reveals a trend line in the SW-NE direction, corresponding to the Andean mountain range, which coincides with the strike of the main geological faults existing in the SW of the country. In this work, earthquake parameters are computed from macroseismic data. The moment magnitude obtained is 6.6 ± 0.2. The epicentre is located at the coordinates 3.29° N and 76.91° W, at approximately 50 km SW from the town of Cali.419 98 - PublicationOpen AccessLa amenaza sísmica de la Sabana de Bogotá frente a un sismo de magnitud M > 7.0, cuyo origen esté en el Piedemonte LlaneroEn este trabajo se muestra cómo un gran sismo originado en el Sistema de Fallas de la Falla Frontal de la Cordillera Oriental (SFFFCO) puede causar grandes daños y pérdidas de vidas, tanto en el área metropolitana de Bogotá, D. C., como en el resto de la Sabana de Bogotá. El grado de la amenaza sísmica de la ciudad ante un sismo cercano, originado en el Piedemonte Llanero, cuya distancia es inferior a 250 km y con una magnitud > 7.0, es muy alto, si se tiene presente que sus suelos, de origen lagunar, se ubican hacia el occidente y el noroccidente, zonas en las que, durante las dos últimas décadas, se ha ido extendiendo el área metropolitana.
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