Application of multiple proxies in Mexican tropical coasts to prove evidence of tsunami deposits

"The study of tsunami deposits has significantly advanced since the Chilean 2010 and Tohoku 2011 tsunamis providing opportunities to analyze tsunami deposits and their characteristics (Rubin et al., 2017)." (fragm.

Sand deposits reveal great earthquakes and tsunamis at Mexican Pacific Coast

Globally, instrumentally based assessments of tsunamigenic potential of subduction zones have underestimated the magnitude and frequency of great events because of their short time record. Historical and sediment records of large earthquakes and tsunamis have expanded the temporal data and estimated size of these events. Instrumental records suggests that the Mexican Subduction earthquakes produce relatively small tsunamis, however historical records and now geologic evidence suggest that great earthquakes and tsunamis have whipped the Pacific coast of Mexico in the past. The sediment marks of centuries old-tsunamis validate historical records and indicate that large tsunamigenic earthquakes have shaken the Guerrero-Oaxaca region in southern Mexico and had an impact on a bigger stretch of the coast than previously suspected. We present the first geologic evidence of great tsunamis near the trench of a subduction zone previously underestimated as potential source for great earthquakes and tsunamis. Two sandy tsunami deposits extend over 1.5 km inland of the coast. The youngest tsunami deposit is associated with the 1787 great earthquake, M 8.6, producing a giant tsunami that poured over the coast flooding 500 km alongshore the Mexican Pacific coast and up to 6 km inland. The oldest event from a less historically documented event occurred in 1537. The 1787 earthquake, and tsunami and a probable predecessor in 1537, suggest a plausible recurrence interval of 250 years. We prove that the common believe that great tsunamis do not occur on the Mexican Pacific coast cannot be sustained

Reformas borbónicas en el obispado de Guadalajara. Division de curatos, negociacion y discurso cartografico

En el mundo hispano de los siglos XVI a XIX, el conflicto y la negociación fueron constantes como vía para lograr la articulación entre las diversas corporaciones que integraban el orden social, cada una con sus propios privilegios y obligaciones. Cuando la política de los Borbón para racionalizar la administración de sus territorios de ultramar suscitó nuevas tensiones entre representantes de la Corona y poblaciones locales, el empleo de la cartografía fue un recurso eficaz para trasmitir los argumentos de los pueblos y de sus grupos dirigentes a la jerarquía eclesiástica y otros representantes del monarca. Este trabajo analiza el uso de nuevas formas de representar el territorio que fueron utilizadas en el proceso de división de curatos en el obispado de Guadalajara, para obedecer el mandato real de reducir las grandes distancias entre cabeceras parroquiales y los feligreses.Conflict and negotiation were the paths that led to the articulation of the diverse corporations that made up society in the Spanish Empire from the 16th to 18th centuries, each with its own privileges and obligations. When the Bourbon Reforms were implemented in the late 18th century to rationalize the administration of the Empire and its overseas territories, new tensions grew between the Crown’s representatives and local populations, but cartography emerged as an efficient tool for transmitting the arguments of those localities and their power groups to the ecclesiastical hierarchy and other representatives of the Crown. This article analyzes the use of those new forms forrepresenting territory within the process of delimiting parishes in the Bishopric of Guadalajara the latter’s purpose was to comply with Royal orders to reduce the great distances that often separated parish seats from the populations they served.Entre les XVIe et XIXe siècles, le monde hispanique a fait constamment l’expérience du conflit et de la négociation comme forme d’articulation entre les différentes corporations qui intégraient cette société. Lorsque la politique bourbonienne, qui visait la rationalisation de l'administration dans les territoires d'outre-mer, a causé de nouvelles tensions entre les représentants de la Couronne et la population locale, l'emploi de la cartographie s'est révélé comme un instrument efficace pour la transmission des arguments des peuples et de leurs élites dirigeantes à la hiérarchie ecclésiastique et aux représentants du roi. Ce travail analyse les différentes modalités de représentation territoriale employés pour rendre compte de la division des paroisses dans l'évêché de Guadalajara, en accord avec l'ordonnance royale qui préconisait de réduire la distance entre les centres paroissiaux et la population locale

La visualización del tiempo: de los sistemas de información geográfica a la animación cartográfica

In this article, we attempt to discuss the potential of visualizations of time from a theoretical and practical point of view. Theoretical issues that will concern us include the general characteristics of time, the extension of Bertin’s (1967) visual variables by the dynamic variables of DiBiase et al. (1992) and a typology of cartographic animations in order to structure the time-factor in a comprehensive manner. Based on these theoretical fundamentals we will analyze the abilities of current geographic information systems (GIS) to visualize temporal data. In doing so, we won’t just focus on the advances and limitations of current GIS, but also outline how geodata exported from the GIS may be enriched in multimedia authoring software so that animations of dynamic processes can be built. The actualization of the Atlas on the risk of natural phenomena in Jalisco will give occasion to illustrate both practical and theoretical aspects in the present contribution.Revista Ciencias Espaciales, Volumen 8, Número 2 Otoño, 2015; 97-112 El trabajo propuesto pretende discutir el potencial de visualizaciones del tiempo desde una perspectiva teórica y práctica. Las preguntas teóricas abarcan las características del tiempo, la ampliación de las variables visuales de Bertin (1967) con las variables dinámicas de DiBiase et al. (1992) y una tipología de animaciones para estructurar el factor “tiempo” exhaustivamente. A partir de estas bases teóricas podemos analizar, cómo los Sistemas de Información Geográfica (SIG) permiten actualmente la visualización de datos temporales. Sin embargo, este análisis no se limita en una descripción de avances y limitaciones de los SIG, sino que intenta mostrar cómo datos espaciales exportados desde un SIG pueden ser enriquecidos mediante el tratamiento con software de autoría multimedia para la realización de visualizaciones animadas de procesos dinámicos. La actualización del Atlas de riesgos por fenómenos naturales del Estado de Jalisco se usará para ilustrar aspectos tanto teóricos como prácticos del presente artículo.Revista Ciencias Espaciales, Volumen 8, Número 2 Otoño, 2015; 97-11

Magnetic record of extreme marine inundation events at Las Salinas site, Jalisco, Mexican Pacific coast

<div><p>ABSTRACT</p><p>Extreme marine inundation events (i.e. severe storms and tsunamis) denote a major hazard to coastal communities around the globe. In order to assess this hazard, long-term (beyond the instrumental and historic records) information on the magnitude and frequency of these events is critical. The coastal sedimentary record, together with other proxies, is now being tested to distinguish and reconstruct evidence of ancient inundation events. Recent studies commonly use anisotropy of magnetic susceptibility (AMS) parameters without statistical evaluation of the lateral variability of sedimentary layers. Here, we provide results from tested sedimentary layers. Moreover, we discuss the most recent strategies to identify deposits produced by major inundation events using the full battery of rock magnetic properties of sediments in Careyes Bay on the Jalisco coast, Eastern Pacific, a tectonically active coast subject to hurricanes. Oriented samples of lagoonal sediments were taken from a dug pit at Las Salinas site. The sampled stratigraphic sequence was basically composed of an upper sand and lower clay units. The upper part of the Las Salinas profile shows a drop in magnetic susceptibility by 50%. Two distinct magnetic fabrics are clearly identified. Fabric from the upper part of the profile most probably reflects a sedimentary structure which was originated in a more dynamic environment than the magnetic fabric recognized in the lower part of the profile. Hysteresis parameters also show variation in behaviour between the upper and lower parts of the profile. We propose here that the origin of the upper sand unit at the study site is most probably related to an extreme marine inundation event.</p></div