Artículos científicos

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/14610

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Mostrando 1 - 4 de 4

Abundancia, biomasa y estructura de la ictiofauna demersal en el Océano Pacífico de Centroamérica, con base en la prospección pesquera realizada a bordo del R / V Miguel Oliver
(Universidad Nacional (Costa Rica), 2020-01) BENAVIDES, ROSARIO; Campos-Calderón, Fernando; Vargas-Hernández , José Mauro
A razón de ampliar el conocimiento sobre la estructura y composición de la ictiofauna demersal en el Pacífico de Centroamérica, se realizó el estudio de muestras obtenidas en 98 puntos de arrastre efectuados con el B/O Miguel Oliver entre el 10 de noviembre y el 16 de diciembre de 2010. Con una red tipo Lofoten, se faenó por 30 minutos sobre los puntos ubicados según estratos y profundidad (máxima 1 600 m). La muestra total (17 507 ejemplares) tuvo representación de peces cartilaginosos y óseos divididos en 77 familias y 158 especies. Dicrolene filamentosa (12.27%) mostró la mayor abundancia, las biomasas más representativas del estudio fueron de Peprilus medius (35.67%) y Peprilus snyderi (12.49%) junto con Rhinoptera steindachneri (9.45%), mientras que las especies más frecuentes fueron Peristedion barbiger y Stomias atriventer (ambas con 2.71%). La costa frente a Costa Rica y Panamá mostró diversidad alta (H’:3), mientras que la equidad presentó valores uniformes. Para determinar ensamblajes con respecto a la profundidad, se utilizó un ordenamiento espacial que mostró un agrupamiento de 3 conjuntos (PERMANOVA, R = 0.54, P > 0.05) y un análisis canónico de correspondencia, el cual arrojó evidencia suficiente de que las especies fueron influenciadas en su distribución por la salinidad y la temperatura. La ictiofauna encontrada responde a eventos y condiciones ambientales particulares que revisten de gran importancia ecológica los hallazgos. Se resalta lo fundamental de los ensamblajes para evaluar cómo las poblaciones cambian como resultado de las características que exhiben las masas de agua.
Numerical Simulations of the 1991 Limón Tsunami, Costa Rica Caribbean Coast
(Springer (Alemania), 2017) Chacon-Barrantes, Silvia; Zamora, Natalia
The second largest recorded tsunami along the Caribbean margin of Central America occurred 25 years ago. On April 22nd, 1991, an earthquake with magnitude Mw 7.6 ruptured along the thrust faults that form the North Panama ́ Deformed Belt (NPDB). The earthquake triggered a tsunami that affected the Caribbean coast of Costa Rica and Panama ́ within few minutes, generating two casualties. These are the only deaths caused by a tsunami in Costa Rica. Coseismic uplift up to 1.6 m and runup values larger than 2 m were measured along some coastal sites. Here, we consider three solutions for the seismic source as initial conditions to model the tsunami, each considering a single rupture plane. We performed numerical modeling of the tsunami propagation and runup using NEOWAVE numerical model (Yamazaki et al. in Int J Numer Methods Fluids 67:2081–2107, 2010, doi: 10.1002/fld.2485 ) on a system of nested grids from the entire Caribbean Sea to Limo ́n city. The modeled surface deformation and tsunami runup agreed with the measured data along most of the coastal sites with one preferred model that fits the field data. The model results are useful to determine how the 1991 tsunami could have affected regions where tsunami records were not preserved and to simulate the effects of the coastal surface deformations as buffer to tsunami. We also performed tsunami modeling to simulate the consequences if a similar event with larger magnitude Mw 7.9 occurs offshore the southern Costa Rican Caribbean coast. Such event would generate maximum wave heights of more than 5 m showing that Limo ́n and northwestern Panama ́ coastal areas are exposed to moderate-to-large tsunamis. These simulations considering historical events and maximum credible scenarios can be useful for hazard assessment and also as part of studies leading to tsunami evacuation maps and mitigation plans, even when that is not the scope of this paper.
The rock coast of South and Central America
(Geological Society Memoirs 2014, 2014-07) Blanco-Chao, Ramon; Pedoja, Kevin; Witt, César; martinod, joseph; Husson, Laurent; Regard, Vincent; Audin, Laurence; Nexer, Maëlle; delcaillau, bernard; Saillard, Marianne; Melnick, Daniel; Dumont, Jean Francois; Santana, Essy; Navarrete, Edison; Martillo, Carlos; PAPPALARDO, MARTA; Ayala, Luis; Araya, J.F.; Feal-Pérez, A.; Correa, D.; Arozarena-Llopis, Isabel
The great variety of climatic conditions, tidal ranges and wave regimes of South and Central America act on a complex geology and tectonic framework. Many of the rock and cliffed coasts of South America are strongly controlled by the occurrence of extensive Cenozoic and Pleistocene sediments that crop out at the coast. Geology and the different uplift rates are a major factor inthe whole coastal geomorphology of South and Central America, and consequently are a very important control of the processes andlandforms of rock coasts. This chapter covers several aspects of the rock coast of South and Central America, with special attention to the combination of tectonic movements and Quaternary Pleistocene–Holocene sea-level changes
Variations in the geostrophic circulation pattern and thermohaline structure in the Southeast Central American Pacific
(Revista de Biologia Tropical vol.64 suppl.1 s121-s134 2016, 2016-03) Brenes, Carlos; Ballestero, Daniel; Benavides, Rosario; Salazar, Juan Pablo; Murillo, Gustavo
This study was conducted in the southeast region of the Central American Pacific, an area of great oceanographic importance due to the presence of various upwelling phenomena and the direct influence of the ENSO on its waters. Its main objective was to contribute to the knowledge of the main factors that modulate the regional dynamics. We describe the geostrophic circulation and thermohaline features along two transects obtained in October 2010 and March 2011, one from Costa Rica at (84°54’ W - 9°37’ N) to the SW of Cocos Island at (88°19’ W - 3°06’ N), and the second oriented zonally across the island from (88°14’ W - 5°33’ N) to (84°33’ W - 5°33’ N). Surface temperatures ranged from 27°C to 29°C and a near isothermal layer, with an average thickness of 40 m, was apparent above the thermocline centered at 60 m. Surface salinities were between 32 and 32.8, typical values of the Tropical Surface Water. In both years, Cocos Island was located in a region of low surface salinities (~32). The salty core of the Subtropical Subsurface Water (~35) was located at an average depth of 150m. In October the circulation between Cocos Island and the continent was dominated by the presence of the North Equatorial Countercurrent (NECC), with speeds above 40 cm s-1 in the upper 50 m of the water column. No flow to the northwest near the coast that could be associated with the Costa Rica Coastal Current (CRCC) in October was observed. The Cocos Island was located in the center of a 150 m deep, 100 km diameter anticyclonic eddy, with surface speeds of 10 cm s-1and 20 cm s-1. In March the study area was again dominated by an anticyclonic cell, with eastward flow between 50 cm s-1 and 60 cm s-1 located between 200 km north and 100 km south of the island. The southern end of this cell, with velocities between 10 cm s-1 and 50 cm s-1 to the northwest, was located 200 km south of Cocos Island. A flow to the NW near the edge of the continental shelf, consistent with the CRCC, was observed in May. Our study contributes to document the oceanography of the eastern end of the Equatorial Current System near the coast of Central America, where regional forcing modifies the zonal flow which prevails west of the study area. © 2016, Universidad de Costa Rica. All rights reserved.

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