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The Térraba-Sierpe Reserve has the largest mangrove in Costa Rica but has suffered from changes in sea level. I used published data to analyze the area and found that sea level rise, generated by coast subsidence or global warming, created a new platform for waves and changed the beach profile and sediment type. Increased sediment deposition on the north maintains the balance of this system, with a sediment gain on the island in front of the Térraba river mouth. A lower sediment output from the Sierpe river is generating a landward delta migration, especially in the southern part, a symptom of local sea level rise. Future scenarios of greater wave energy and additional sea level rise will not allow a dynamic sediment balance, especially on the southern part of the delta, and will generate a loss mangrove cover. © 2015, Universidad de Costa Rica. All rights reserved.

Dzierma Y.,University of Kiel | Rabbel W.,University of Kiel | Thorwart M.M.,University of Kiel | Flueh E.R.,University of Kiel | And 2 more authors.
Geochemistry, Geophysics, Geosystems | Year: 2011

The deep structure of the south-central Costa Rican subduction zone has not been studied in great detail so far because large parts of the area are virtually inaccessible. We present a receiver function study along a transect of broadband seismometers through the northern flank of the Cordillera de Talamanca (south Costa Rica). Below Moho depths, the receiver functions image a dipping positive conversion signal. This is interpreted as the subducting Cocos Plate slab, compatible with the conversions in the individual receiver functions. In finite difference modeling, a dipping signal such as the one imaged can only be reproduced by a steeply (80) dipping structure present at least until a depth of about 70-100 km; below this depth, the length of the slab cannot be determined because of possible scattering effects. The proposed position of the slab agrees with previous results from local seismicity, local earthquake tomography, and active seismic studies, while extending the slab location to greater depths and steeper dip angle. Along the trench, no marked change is observed in the receiver functions, suggesting that the steeply dipping slab continues until the northern flank of the Cordillera de Talamanca, in the transition region between the incoming seamount segment and Cocos Ridge. Considering the time predicted for the establishment of shallow angle underthrusting after the onset of ridge collision, the southern Costa Rican subduction zone may at present be undergoing a reconfiguration of subduction style, where the transition to shallow underthrusting may be underway but still incomplete. Copyright © 2011 by the American Geophysical Union.

The aquatic insects have been used to evaluate water quality of aquatic environments.The population of aquatic insects and the water quality of the area were characterized according to the natural and human alterations present in the study site. During the monthly-survey, pH, DO, temperature, water level, DBO, PO4 and NO3 were measured. Biological indexes (abundance, species richness and the BMWP-CR) were used to evaluate the water quality. No relation between environmental and aquatic insects was detected. Temporal and spatial differences attributed to the flow events (temporal) and the presence of Peñas Blancas reservoir (spatial). In the future, the investigations in Peñas Blancas watershed need to be focused on determining the real influence of the flows, sediment release and the possible water quality degradation because of agriculture activities.

Vega D.C.,Instituto Costarricense Of Electricidad | Alpizar F.,Tropical Agriculture Research and Higher Education Center
Impact Assessment and Project Appraisal | Year: 2011

Choice experiments, a stated preference valuation method, are proposed as a tool to assign monetary values to environmental externalities during the ex ante stages of environmental impact assessment. This case study looks at the impacts of the Costa Rican Institute of Electricity's Toro 3 hydroelectric project and its impacts on the Recreo Verde tourism center in San Carlos, Costa Rica. Compared to other valuation methods (e.g., travel cost and contingent valuation), choice experiments can create hypothetical but realistic scenarios for consumers and generate restoration alternatives for the affected good. Although they have limitations that must be taken into account in environmental impact assessment, incorporating economic parameters (especially resource constraints and tradeoffs) can substantially enrich the assessment process. © IAIA 2011.

Cordero-Leiton J.,Instituto Costarricense Of Electricidad
Proceedings of the 2014 IEEE Central America and Panama Convention, CONCAPAN 2014 | Year: 2014

The article discusses two very specific study cases where reliability errors occurred at protective relaying functions. The cases took place under fault conditions at the Costa Rican electric power grid. The study cases occurred between 2004 and 2011 in different elements of the transmission system owned by ICE, and they are representative cases in which it was necessary to perform a thorough analysis and laboratory tests. In each case was perform the following tasks: an explanation of the event, a failure categorization under the context of reliability fault type, a relay behavior analysis through its events and disturbance records, laboratory tests conducted to evaluate the behavior of the functions involved, and finally, a description of the corrective actions implemented to solve the detected problem. As a result, was achieved a sample of some of the most interesting experiences in the field of protective relaying maintenance, related to the costarrican electric power transmission network. © 2014 IEEE.

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