Geomorphology of the Caribbean coast of Costa Rica

Geology, 2003

Subduction of hotspot-thickened seafloor profoundly affects convergent margin tectonics, strongly affecting upper plate structure, volcanism, and landscape evolution. In southern Central America, low-angle subduction of the Cocos Ridge and seamount domain largely controls landscape evolution in the volcanic arc. Field mapping, stratigraphic correlation, and 40 Ar/ 39 Ar geochronology for late Cenozoic volcanic rocks of central Costa Rica provide new insights into the geomorphic response of volcanic arc landscapes to changes in subduction parameters (slab thickness, roughness, dip). Late Neogene volcanism was focused primarily along the now-extinct Cordillera de Aguacate. Quaternary migration of the magmatic front shifted volcanism northeastward to the Caribbean slope, creating a new topographic divide and forming the Valle Central basin. Stream capture across the paleo-Aguacate divide led to drainage reversal toward the Pacific slope and deep incision of reorganized fluvial networks. Pleistocene caldera activity generated silicic ash flows that buried the Valle Central and descended the Tárcoles gorge to the Orotina debris fan at the coast. Growth of the modern Cordillera Central accentuated relief along the new divide, establishing the Valle Central as a Pacific slope drainage basin. Arc migration, relocation of the Pacific-Caribbean drainage divide, and formation of the Valle Central basin resulted from slab shallowing as irregular, hotspot-thickened crust entered the subduction zone. The geomorphic evolution of volcanic arc landscapes is thus highly sensitive to changes in subducting plate character.

Ocean & Coastal Management, 2012

and sharing with colleagues.

Anais do X Congresso da …, 2005

Based on geological and geophysical data, satellite imagery, field observations and numerical modeling, the Holocene evolution of the coastal area of Tijucas was studied. The area comprises mainly a coastal plain associated to the Tijucas river (Santa Catarina/Brazil), which presents now-a-days a mean discharge of 40 m 3 /s and complex transport patterns of fine-and coarse-grained sediments. The plain was formed mainly in the last 6 to 5 thousand years due to abundant sediment supply and gentle sea-level fall. Using Ground Penetrating Radar (GPR), coring and elevation measurements the progradational sequences were studied. It was possible to identify two main domains, including a landward lagoonal/estuarine portion and a seaward strandplain. The transgressive Holocene barrier associated to the mid-Holocene sea-level maximum has also been detected, dividing the domains. Seaward of this Holocene barrier the complex strandplain was preliminarily mapped. The extensive information acquired was then used to develop a first Holocene evolution model, which is presented here.

Geomorphology, 1988

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Journal of South American Earth Sciences, 2021

The Torres River is one of the most urbanized catchments in Costa Rica, with only 46.67 km 2 and approximately 50% of its area have urban land uses comprising nearly 13% of the national population. The quick rural-urban transition during the last century has had intense environmental impacts along the Greater Metropolitan Area (GAM) of Costa Rica. We performed a geomorphology map of the Torres River catchment using photointerpretation and digitization processes. We used aerial photographs, contour lines every 5 m, digital elevation models, slope, and hillshade models as a basis. We identified eleven endogenic, fluvial accumulative and erosional, as well as anthropogenic exogenic landforms. The results show that 37% of the catchment is made up of flat lands, 31% corresponds to valley slopes, 22% to mountain slopes, and 6% to valley bottoms. The remaining 4% of the area consists of anthropogenic landforms such as deposits, terraces, quarries, escarpments, and old quarries. Land uses are controlled by the determined landforms and explain the urban growth and subsequent environmental impacts such as erosion, water pollution, and natural hazards occurrence on the catchment. This geomorphological assessment can be implemented for exhaustive morphogenetic maps, landform evolution studies, natural risks, environmental, and land use mapping.

Leaders: F. Borja a (chapter II), A. Rodríguez-Ramírez b (chapter III) and F.J. Gracia (chapters I, IV and V).

Revista Geográfica de América Central, 2020

Since 2010, the local press has been reporting an accelerated process of erosion on the sandy beach-es of the Costa Rican Caribbean coast, it has even been documented within protected areas. To quantify this process and identify coastal erosion hotspots in the Caribbean south, a methodology was proposed for detecting and delineating the shoreline using aerial photographs and high-reso-lution satellite imagery to determine the rate of shoreline retreat, the employed photographs and images cover the period between 2005 and 2016. By such means it was possible to identify eleven erosion hotspots, as well as estimation of their retreat rates for the periods 2005-2010 and 2010-2016. The localities that have experienced the greatest erosion of their sandy beaches are Cahuita National Park, Westfalia and Bananito Beach.

The Manzanilla barrier beach at Cocos Bay has been undergoing marine erosion for decades due to its position against the high energy environment of the Atlantic Ocean. The barrier beach borders the Ramsar listed freshwater Nariva Swamp, offering protection from the marine environment whilst helping to maintain the delicate ecosystem in the wetland. Visible ongoing coastal erosion at this beach threatens the longevity of this internationally protected wetland. Previous studies of coastline erosion at this beach have been restricted to the analysis of beach profile data over short time periods. This paper examines the evolution of the coastline over a 36 year time period from 1958 to 1994. Digital analysis of shorelines from 1958 and 1994 aerial photographs permitted the identification of areas where erosion or deposition was the dominant process over a 36 year time period. Identification of these areas of coastal change, allowed for the lateral extent of erosion or deposition to be quantified using the Digital Shoreline Analysis System (DSAS 4.0). These calculations gave an insight into the long-term rates of erosion and deposition operating within the bay. Direct coastal measurements were also made in the short-term as a calibration of the rates of erosion and deposition from the longer-term GIS analysis. The long-term GIS analysis revealed much slower erosion rates than previously reported in short-term studies. Results indicate that analyzing short-term erosion rates alone may exaggerate the true rates of erosion at this bay.

Recent Geodetic and Gravimetric Research in Latin America, 1993

2021

Coastal zones are highly dynamic environments that provide a range of ecosystem services. They are influenced by natural and anthropogenic factors, leading to increasingly drastic changes which have negative impacts on biological diversity and human communities. The present study characterizes the beaches of the Southern Caribbean of Costa Rica (SC-CR) to provide a baseline for marine-coastal management. Eight beaches of the SC-CR were studied, and 47 transects were defined in which the following information was obtained: beach width, scarp width and height, average particle size in dunes, plant species, and vegetation cover and height. Puerto Viejo and Vizcaya were determined to have the greatest average width, while Manzanillo and Gandoca had the smallest. In 25.24% of the sampled points there were signs of erosion. The width of the scarp varied from 3.90 m to 43.70 m and the height between 15 cm and 70 cm. The sand particles in 87.5% of the beaches were medium-sized. A total of 2...