Facultad de Ciencias de la Tierra y el Mar

URI permanente para esta comunidadhttp://10.0.96.45:4000/handle/11056/14052

La Facultad de Ciencias de la Tierra y Mar (FCTM) de la Universidad Nacional (UNA), se crea en el año 1973 y desde sus inicios se ha caracterizado por su compromiso con los principios y valores que sustentan la Universidad Necesaria; la cual en lo fundamental se caracteriza por la búsqueda de nuevos espacios que le permitan seguir aportando a la sociedad profesionales y productos de la investigación, extensión y servicios que contribuyan a la mejora en la calidad de vida de la población costarricense y sus relaciones con la naturaleza.

Decana: Grace Wong Reyes, Ph.D, correo electrónico: grace.wong.reyes@una.cr

Contacto:

Página web: www.tierraymar.una.ac.cr

Correo: fctm@una.cr

Teléfono: (506) 2277-3226 / (506) 2277-3280

Biblioteca Especializada Facultad de Ciencias de la Tierra y el Mar:

Página web: www.bctm.una.ac.cr

Correo: bctm@una.cr

Teléfono: 2562-6490 / 2562-6491

Facebook: @BibliotecaTierrayMar

Instagram: @biblioteca.tierraymar

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Mostrando 1 - 4 de 4

A brittle failure model for long-period seismic events recorded at Turrialba Volcano, Costa Rica
(American Geophysical Union, 2015-01-30) Eyre, Thomas; Bean, Christopher; DE BARROS, LOUIS; Martini, Francesca; Lokmer, Ivan; Mora Fernández, Mauricio Manuel; Pacheco, Javier F.; Soto, Gerardo J.
A temporary seismic network, consisting of 23 broadband and six short-period stations, wasinstalled in a dense network at Turrialba Volcano, Costa Rica, between 8 March and 4 May 2011. During thistime 513 long-period (LP) events were observed. Due to their pulse-like waveforms, the hypothesis thatthe events are generated by a slow-failure mechanism, based on a recent new model by Bean et al. (2014), istested. A signiﬁcant number (107) of the LPs are jointly inverted for their source locations and mechanisms,using full-waveform moment tensor inversion. The locations are mostly shallow, with depths < 800 m belowthe active Southwest Crater. The results of the decompositions of the obtained moment tensor solutions showcomplex source mechanisms, composed of high proportions of isotropic and low, but seemingly signiﬁcant,proportions of compensated linear vector dipole and double-couple components. It is demonstrated that thiscan be explained as mode I tensile fracturing with a strong shear component. The source mechanism is furtherinvestigated by exploring scaling laws within the data. The LPs recorded follow relationships very similar tothose of conventional earthquakes, exhibiting frequency-magnitude and corner frequency versus magnituderelationships that can be explained by brittle failure. All of these observations indicate that a slow-failure sourcemodel can successfully describe the generation of short-duration LP events at Turrialba Volcano
Comparison of land use change in payments for environmental services and National Biological Corridor Programs
(Elsevier, 2017-04-20) Wood, Margot A.; Sheridan, Ryan; Feagin, Rusty A.; Castro, Jose Pablo; Lacher Jr, Thomas E.
Costa Rica established the National Biological Corridors Program in 2006. Within the framework of the National Program for Biological Corridors, the long-standing Biological Corridor, the long-standing Payment for Environmental Services Program was again prioritized in biological corridors throughout the country. The National Biological Corridor Program brought about a nationwide spatial shift in the placement of payments for environmental services throughout Costa Rica. We classified 15-m resolution ASTER imagery in a central corridor of Costa Rica connecting the eastern and western protected area networks to analyze the of protected areas in eastern and western Costa Rica to analyze the change in forests during the of forests during the National Biological Corridors Program with its payments for environmental services effort. We used object-based classification ranking methods, and compared changes in land cover during an initial four-year period of enactment of the corridor policy. We calculated changes within PES properties and outside PES regions, and also calculated forest plot metrics over the same time period. The results indicate a decrease in forest cover during the study period, along with an increase in urban and grassland cover, with greater change and forest in the biological corridor, near the construction zone of the new San Carlos Highway and in the eastern grassland areas of the new San Carlos Highway, and in the eastern grassland areas of the new San Carlos Highway. A higher percentage of forest loss was also observed within the biological corridor compared to areas outside the biological corridor. Forest loss was drastically less within the current and historic PES properties compared to the study region overall. Across the study region, patch metrics show a decrease in the number of patches and a slight decrease in average patch size. These results suggest that current and past PES designation prevents forest loss within forests within PES properties, while current designation of priority conservation status through the National Biological Corridors Program is not increasing connectivity. The National Biological Corridors Program is not increasing connectivity or forest conservation. This is demonstrated by the increase in land use change and decrease in forests associated with biological corridor designation. These results are antithetical to the objectives of the National Biological Corridors Program.
Field testing passive air samplers for current use pesticides in a tropical environment
(Universidad Nacional, Costa Rica., 2008) Gouin, Todd; Wania, Frank; Ruepert, Clemens; Castillo, Luisa E.
Air was sampled for one year in the central valley of Costa Rica using an active high-volume sampler as well as passive samplers (PAS) based on polyurethane foam (PUF) disks and XAD-resin filled mesh cylinders. Extracts were analyzed for pesticides that are either banned or currently used in Costa Rican agriculture. Sampling rates for PUF-based passive air samplers, determined from the loss of depuration compounds spiked on the disks prior to deployment, averaged 5.9 +- 0.9 m3 · d-1 and were higher during the windier dry seasonthan duringthe rainy season. Sampling ratesforthe XADbased passive sampler were determined from the slopes of linear relationships that were observed between the amount of pesticide sequestered in the resin and the length of deployment, which varied from 4 months to 1 year. Those sampling rates increased with decreasing molecular size of a pesticide, and their average of 2.1 +- 1.5 m3 · d-1 is higher than rates previously reported for temperate and polar sampling sites. Eventhoughthetrends ofthe sampling rate with molecular size and temperature are consistent with the hypothesis that molecular diffusion controls uptake in passive samplers, the trends are much more pronounced than a direct proportionality between sampling rate and molecular diffusivity would suggest. Air concentrations derived by the three sampling methods are within a factor of 2 of each other, suggesting that properly calibrated PAS can be effective tools for monitoring levels of pesticides in the tropical atmosphere. In particular, HiVol samplers, PUF-disk samplers, and XADbased passive samplers are suitable for obtaining information on air concentration variability on the time scale of days, seasons and years, respectively. This study represents the first calibration study for the uptake of current use pesticides by passive air samplers.
Maternal blood and hair manganese concentrations, fetal growth, and length of gestation in the ISA cohort in Costa Rica
(Environmental Research, 2015-01) Mora, Ana Maria; van Wendel de Joode, Berna; Mergler, Donna; Cordoba, Leonel; Cano, Camilo; Quesada, Rosario; Smith, Donald R.; Menezes-Filho, José; Eskenazi, Brenda
Background: Animal studies have shown that both deficiency and excess manganese (Mn) may result in decreased fetal size and weight, but human studies have reported inconsistent results. Methods: We examined the association of blood and hair Mn concentrations measured at different times during pregnancy with fetal growth among term births and length of gestation in a cohort of 380 mother-infant pairs living near banana plantations aerially sprayed with Mn-containing fungicides in Costa Rica. We used linear regression and generalized additive models to test for linear and nonlinear associations. Results: Mean (± SD) blood Mn concentration was 24.4±6.6μg/L and geometric mean (geometric SD) hair Mn concentration was 1.8 (3.2) μg/g. Hair Mn concentrations during the second and third trimesters of gestation were positively related to infant chest circumference (β for 10-fold increase=0.62cm; 95% CI: 0.16, 1.08; and β=0.55cm; 95% CI: -0.16, 1.26, respectively). Similarly, average maternal hair Mn concentrations during pregnancy were associated with increased chest circumference (β for 10-fold increase=1.19cm; 95% CI: 0.43, 1.95) in infants whose mothers did not have gestational anemia, but not in infants of mothers who had gestational anemia (β=0.39cm; 95% CI: -0.32, 1.10; pINT=0.14). All these associations were linear. Blood Mn concentrations did not show consistent linear nor nonlinear relationships with any of the birth outcomes. Conclusions: Mn plays an important role in fetal development, but the extent to which environmental exposures may cause adverse health effects to the developing fetus is not well understood. Among women living near banana plantations in Costa Rica, we did not observe linear or nonlinear associations of Mn concentrations with lowered birth weight or head circumference, as reported in previous studies. However, we did find positive linear associations between maternal hair Mn concentrations during pregnancy and infant chest circumference

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