Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

In April 2017 Poás volcano produced at least 4 main eruptions that reshaped completely its active crater and surroundings. Holy Wednesday eruption impacted the west sector and its related flanks, Thursday eruptions produced more effects towards the southeast and south involving the main viewpoint and vicinity while holy Friday eruptions were directed towards the southeast and east impacting, partially, the forest. Finally, on April 22nd the last of the main eruptions occurred disappearing the rest of the standing dome and, again, affecting the viewpoint and surroundings; including volcano monitoring equipment. Changes were produced; directly at the bottom of the crater and on the dome while sectors near that cavity, were transformed mainly by infilling of materials ejected from the two mentioned structures. This essay offers a description of the main materials emplaced in each sector, their physical characteristics and coverage. This work will depict a comparative vision of previous geomorphological conditions with the current eruptive period. Various photographic sequences; from different angles and with spatial references, dimension and orientation will help to assess the magnitude of changes generated by this recent activity and its implications for the eruptive future of this volcano. The areal framework of impact does not exceed 2 kms; from the point of emission although some references will have a larger axis. Chronologically the comparison will start from the general conditions left after the phreatic eruptions in 2006.

The present study corresponds to the conformation of acoustic maps based on the collection of  noise data in the urban centers of Heredia, Alajuela and Belén, in Costa Rica donwtown. Therefore, a sampling was carried out using sites of complaint for noise pollution in Alajuela and Belén, while in Heredia the vertices of each quadrants in Central District were used as a sampling site. The most important result obtained in this study is related to the identification of mostly sites withnoise levels that exceed the permissible limits established in the Regulation that can be observed graphically in the acoustic maps. This leads to the following conclusion the acoustic maps represent a fundamental tool for the noise control and to plan the mitigation strategies and confinement of noise pollution areas.

This study presents a zoning of land use conflicts in protection areas (AP) of drainages of the Páez river basin. The zoning was delimited and quantified through spatial analysis processes, based on the level curves (1: 10 000) and the digitization of orthophotos. Resulting 59% of the total of AP (7,397 km2) which have a land use conflict. The zoning area with land use conflicts (4,374 km2) was distributed: an 4% in category I (permanent crop), an 81% in category II (agricultural and crops) and finally an 16% in category III (housing, infrastructure and others). The conflict generated by crops and smaller scale by the agricultural use predominate in the degradation of the AP functions at the basin. Confirming the anterior information, the index of land use conflicts (GC) proposed by Danza and Sanabria (2008) resulted in -0.13, evidencing a high affectation in the AP due to inadequate land use. The sub-basins 3, 4, 5, 6, 14 y 20 indicates a major conflict, therefore, mitigation measures should be a priority in this spatial area. 

This research proposes the formulation of a fragmentation / connectivity index that assesses the condition of natural cover at the canton level for Costa Rica based on spatial distribution considering the variables: area of the county, the natural coverage area, the number of fragments and distance of neighborhood between the fragments of the natural cover, for the years 2000 and 2015. The images Landsat 7 for the year 2000 and Landsat 8 for the year 2015 were used where the land use categories for each year were derived through supervised classification with ERDAS software and with ArcMap10.5 biometric indices were estimated using the Vargas equation (2008) which was modified for its application. Within the results, we identified the cantons that present greater or lesser fragmentation and connectivity of their natural coverage during the study period.

En los periodos 1910-1912, 1951-1955 y 1990-1993 se localizaron en el Valle Central de Costa Rica sismos superficiales importantes, por su magnitud y daños causados en la población, estructura y paisaje. La recurrencia de estos sismos es de aproximadamente cada 40 años y sucedieron entre 7 y 10 años, después de haber ocurrido los sismos mayores de subducción de 1904, 1941 y 1983 en la Península de Osa. En la zona central del país, también han ocurrido sismos esporádicos con magnitud de moderada a fuerte y que han causado daños. Por ejemplo, el sismo de Orotina de 1924, Pérez Zeledón de 1983, de Cinchona 2009 y Capellades del 2016. Si consideramos todos los sismos más importantes que han ocurrido en el interior de la parte central del país desde inicios del siglo XX y que han causado daños en el Valle Central; el período de recurrencia es de 21 años y la probabilidad de que el próximo se presente antes del 01/01/2038; 21 años después de haber ocurrido el sismo de Capellades el 01/12/2016, es mayor a 0.86 con un intervalo de confiabilidad del 95% de [0.71, 0.98].

En este trabajo se hace una descripción de la fuente sísmica del sismo de Capellades, provincia de Cartago, Costa Rica, del 1 de diciembre de 2016, 00:25:20 hora UTC. Se estudian los parámetros de la fuente, centroide, momento, magnitud, mecanismo focal; así como hypocentro de las réplicas y sus magnitudes. También se hace una descripción de la sismicidad en la zona epicentral antes del sismo de Capellades. Los datos usados en el análisis fueron registrados por la red sísmica del Observatorio Vulcanológico y Sismológico de Costa Rica de la Universidad Nacional (OVSICORI-UNA) y el Laboratorio de Ingeniería de la Universidad de Costa Rica (LIS-UCR). El sismo principal se localizó con una profundidad hipocentral de 3.0 km, 3.7 km al NNO de Capellades, con una magnitud (Mw) de 5.2. Éste sismo se ubica entre los volcanes Turrialba e Irazú; Cordillera Volcánica Central de Costa Rica. La solución del tensor de momento indica una falla transcurrente dextral, casi vertical (buzamiento 82°), rumbo 155° y deslizamiento 174°; con un centroide a 6 km de profundidad. El eje de presión está indicado por un strike y dip de 21°/1°; es decir, con una dirección SSO-NNE y el de tensión de 111°/10°; indicando una tensión en la dirección SEE-NOO. En general, el mecanismo focal obtenido usando inversión de ondas o el impulso de los primeros arribos indican una falla transcurrente, con ejes de presión y tensión horizontales en concordancia con los esfuerzos de otros eventos sísmicos intraplaca moderados y ligeros que han ocurrido en el arco volcánico central de Costa Rica. En 5 días de actividad sísmica, en la zona comprendida entre 9.9 y 10.12 latitud norte, 83.9 y 83.72 longitud oeste, se localizaron 1923 sismos; todas las réplicas con magnitudes menores a 4.0 grados en la escala Richter. La relocalización de las réplicas muestra una tendencia epicentral con dirección NO-SE, con buzamiento al SO y concentrada en un área de 32 km2. El rumbo de 155° coincide con la tendencia mostrada por los epicentros de las réplicas, lo que indica el azimut de traza de la falla. La zona del Irazú-Turrialba, donde ocurrió el sismo del 1 de diciembre 2016, mostró microsismicidad meses y años antes del sismo principal, pero no se tenía conocimiento de sismos similares a éste, en el área de ruptura.

Arsenic (As) concentrations in water samples for human consumption and use were determined in 106 communal supply system operators in the Chorotega and Huetar Norte regions of Costa Rica during 2013-2017. The samples that recorded As concentrations above the national standard were evaluated for the remaining parameters included in level N3 of the Regulation for drinking water of Costa Rica. The determination of arsenic was made using atomic absorption spectrometry with graphite furnace. The main non-compliances were registered in the districts of Bagaces and Cañas, while in the Huetar Norte region they are presented in Agua Zarcas and Los Chiles. In these districts there is a level of non-compliance with the national standard (10 μg / l) that varies from 66.7% in the case of Los Chiles to 50% in Cañas. The systems that present breaches by As did not register significant temporal variations in the 2013-2017 period. When analyzing the parameters of significant correlations recorded between the As and the other species analyzed, valuable information is obtained related to the hydrogeochemical processes that determine the presence of this metalloid.

The production of socio-spatial inequality in the Metropolitan Area of San Salvador, El Salvador, between 1950 and 1979, is analyzed from the critique and use of the notion of social division of residential space elaborated by Emilio Duhau, strengthening this concept from theoretical tools of radical geography and sociological class analysis, giving rise to the proposed theoretical-conceptual framework. This formulation discusses with a selection of studies dealing with the urbanization process, the housing problem or housing policies in the Salvadoran metropolis that provide information on the process of housing occupancy of various social classes inside, also incorporating other studies that provide the economic, political and social context of the period analyzed. The study demonstrates the effects of the capitalist mode of production on the social division of residential space, emphasizing the role of housing policies and the processes of land occupation of the popular classes.

The situation of environmental deterioration and the absence of a Regulatory Plan, has motivated the establishment of Risk Management alternatives to residents of some neighborhoods through talks, trainings, delivery of informative material and field practices. This has led to the formation of Neighborhood Emergency Committees, where the incorporation of residents has established a substantial difference in the identification, surveillance and attention of risky sites, with evident improvements in the community organization and self-care.

This study explores the academic profession in Mexico at two times: when academic careers were governed by salaries, and the subsequent period in which they were regulated by “merit-based pay”. This analysis uses data from the study “The Changing Academic Profession (CAP) in Mexico” (2007) with respect to members of the National System of Researchers (SNI), and splits the sample into two groups: veterans and young academics, the former from the first period and the latter from the period when academic careers were shaped by Conditional Monetary Transfers (TMC, in Spanish). Three indicators were constructed: time taken to obtain a doctorate degree, time taken to hold a full-time position, and previous education upon entry into an academic career. The results of the comparison show that Conditional Monetary Transfers changed the timing of education and entry into the academic career, and the level of education of researchers beginning their career.