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Cenozoic basin development in Hispaniola  

SciTech Connect

Four distinct generations of Cenozoic basins have developed in Hispaniola (Haiti and Dominican Republic) as a result of collisional or strike-slip interactions between the North America and Caribbean plates. First generation basins formed when the north-facing Hispaniola arc collided with the Bahama platform in the middle Eocene; because of large post-Eocene vertical movements, these basins are preserved locally in widely separated areas but contain several kilometers of arc and ophiolite-derived clastic marine sediments, probably deposited in thrust-loaded, flexure-type basins. Second generation basins, of which only one is exposed at the surface, formed during west-northwesterly strike-slip displacement of southern Cuba and northern Hispaniola relative to central Hispaniola during the middle to late Oligocene; deposition occurred along a 5-km (3-mi) wide fault-angle depression and consisted of about 2 km (1 mi) of submarine fan deposits. Third generation basins developed during post-Oligocene convergent strike-slip displacement across a restraining bend formed in central Hispaniola; the southern 2 basins are fairly symmetrical, thrust-bounded ramp valleys, and the third is an asymmetrical fault-angle basin. Fourth generation basins are pull-aparts formed during post-Miocene divergent strike-slip motion along a fault zone across southern Hispaniola. As in other Caribbean areas, good source rocks are present in all generations of basins, but suitable reservoir rocks are scarce. Proven reservoirs are late Neogene shallow marine and fluvial sandstones in third generation basins.

Mann, P.; Burke, K.



Satellite Sees Tropical Storm Chantal Move Over Hispaniola  

NASA Video Gallery

This NOAA GOES-East satellite animation from July 6 to July 10 shows the development of Tropical Storm Chantal in the Atlantic Ocean and movement over Hispaniola by July 10. TRT 0:06 Credit: NASA/N...


Cenozoic sedimentary and deformational history of Hispaniola  

SciTech Connect

Previous workers have recognized that the basement rocks of northern Hispaniola consists of structurally complex volcanic, plutonic, and metamorphic rocks that have been interpreted as a Late Cretaceous-Eocene forearc and trench complex. Questions that have remained poorly answered from the study of the basement complex include: (1) why and when did subduction end, and (2) how many arc complexes are present and how and when did accretion occur. In order to answer these questions more satisfactorily, the authors conducted detailed mapping of upper Eocene-lower Miocene marine clastic and carbonate rocks that unconformably overlie the forearc and trench complex. The Cordillera Septentrional consists of a minimum of two distinct arc terranes that have been juxtaposed since the middle Miocene by left-lateral strike-slip faulting oriented slightly oblique (315) to the structural and geomorphic trends of the present-day plate boundary (295). Basement types and overlying sedimentary rock types and ages vary abruptly across the linear, 100-400 m wide shear zone. Southwest of the fault, the basement is made mostly of currently undated, deep-water silty carbonates with interbedded volcanics, whereas to the northeast of the fault, basement consists of a heterogeneous volcanic, plutonic, and metamorphic complex. Fossil dating of sediments is in progress to determine the age of arc activity. The composition of turbidite basins unconformably overlying both basement types closely reflects the underlying basement lithologies. Preliminary biostratigraphic data indicate the southwestern basin (approximately 5,500 m of section) is late Eocene-early Oligocene, whereas the northeastern basin (approximately 2,500 m of section) is early Miocene. Upper Miocene-Pliocene carbonates ( > 300 m thick) cap both basins and suggest post-early Miocene ''docking'' of the basement terranes and their associated basins.

De Zoeten, R.; Mann, P.; Dolan, J.F.; Monechi, S.



Isla Hispaniola: A trans-boundary flood risk mitigation plan  

NASA Astrophysics Data System (ADS)

It is sadly known that over the past decades Isla Hispaniola (Haiti and the Dominican Republic) has been exposed to the devastating passage of several hurricanes and tropical storms. Territories that are economically weak and extremely poor in terms of natural resources have been shaken by severe flood events that caused the loss of thousands of human lives, displacement of people and damage to the environment. On May 24th 2004, the flooding of the trans-boundary river Soliette killed over 1000 Haitian and Dominican people, wiping out villages and leaving behind desolation and poverty. After this catastrophic flood event, the General Direction for Development and Cooperation of the Italian Department of Foreign Affairs funded through the Istituto Italo-Latino Americano (IILA, an international cooperation initiative (ICI), coordinated and directed by the University of Bologna. The ICI involved Haitian and Dominican institutions and was twofold: (a) institutional capacity building on flood risk management and mitigation measures and policies; (b) hydrological and hydraulic analysis of the May 2004 flood event aimed at formulating a suitable and affordable flood risk mitigation plan, consisting of structural and non-structural measures.

Brandimarte, Luigia; Brath, Armando; Castellarin, Attilio; Baldassarre, Giuliano Di


Petrogenesis of the Late Cenozoic volcanics of Hispaniola  

SciTech Connect

Late Cenozoic volcanic rocks of Hispaniola are subdivided into two geochemically contrasting series, a mafic alkaline series (MA-series) and a calc-alkaline series (CA-series). MA-series basalts show slight to moderate silica undersaturation, high TiO/sub 2/ and MgO contents and moderately high total alkalis. MA types are strongly enriched in K, Rb, Sr, Ba, U, Th and LREEs with Ba/La ratios of 0.98. REE patterns are highly fractionated (La/sub n//Yb/sub n/ ratios = 62, and La/sub n//Sm/sub n/ ratios = 6.3). HFS elements Zr, Hf, Nb and Ta are high resembling intraplate basalts. 87Sr/86Sr ratios are high (.7059 to .7079) with low Rb/Sr ratios (.03 to .15). The basalts, basaltic andesites, trachyandesites and dacites of the CA-series show lower TiO2 and MgO contents and moderately high total alkali contents. Strong enrichment is seen in K, Rb, Sr, Th, U and LREEs with Ba/La ratios as high as 5.6. REE patterns are fractionate to a lesser degree compared to the MA-series (average La/sub n//Yb/sub n/ = 23.4, and La/sub n//Sm/sub n/ ratios less than 5). HFS elements are lower resembling typical island arc types. CA-series show lower 87Sr/86Sr ratios (.7043 to .7053), with similarly low Rb/Sr ratios as seen in the MA-series. The MA-series and CA-series must have two separate primary sources as constrained by isotopic and trace element differences. Suggested models involve multi-stage, multi-component petrogenesis. Enrichment of depleted sub-arc mantle by a metasomatic melt fluid followed by second stage partial melting and final fractional crystallization are the principle elements of the preferred model.

Vespucci, P.D.



Taxonomic Revision of Hispaniola Tiger Beetles in the Genus Brasiella Rivalier 1954 (Coleoptera, Carabidae, Cicindelinae)  

PubMed Central

Abstract The Brasiella tiger beetle fauna on Hispaniola, the second largest island of the Greater Antilles, has more species diversity than currently recognized as all populations previously have been assigned to the insular endemic Brasiella dominicana (Mandl). A comparative study of adult morphology, particularly male genitalic and female abdominal characters, for available Brasiella specimens from populations on Hispaniola, proposes eight additional new species also endemic to this island. Except for three sympatric species in the Sierra de Baoruco in southern Dominican Republic occurring in different habitats, all the Brasiella on Hispaniola appear to be allopatric. Most species occur in the major mountainous regions of Hispaniola. Two species, however, are known only from river floodplains in the southern coastal plain of the Dominican Republic. Brasiella dominicana (Mandl) and Brasiella ocoa, new species, occur along river floodplains emanating from the eastern end of the Cordillera Central in the Dominican Republic. Two new Brasiella species, Brasiella bellorum, and Brasiella philipi, occur in the Cordillera Central, Dominican Republic, the former species from central portions, and the latter species from north slopes of this mountain range, respectively. Three new Brasiella species, Brasiella rawlinsi, Brasiella iviei, and Brasiella youngi, are isolated in the Sierra de Baoruco, Dominican Republic, where each occupies a different habitat along an altitudinal gradient. The two new Brasiella species in Haiti are Brasiella darlingtoniana, in the Massif de la Selle, and Brasiella davidsoni, in the Massif de la Hotte. All nine Brasiella species on Hispaniola, along with Brasiella viridicollis (Dejean) and its two subspecies on Cuba, belong to the viridicollis species group of the genus Brasiella based on criteria presented in earlier published phylogenetic studies of Brazilian and West Indian tiger beetles. The subspecies Brasiella viridicollis fernandozayasi (Kippenhan, Ivie and Hopp) may represent a distinct species within this species group, whereas removal of Brasiella wickhami (W. Horn) from this species group seems warranted based on evidence presented. A general overview of species relationships for the Brasiella on Hispaniola are discussed, along with the current and ancestral geographic distributions of the Brasiella viridicollis species group in the West Indies.

Acciavatti, Robert E.



Taxonomic revision of hispaniola tiger beetles in the genus brasiella rivalier 1954 (coleoptera, carabidae, cicindelinae).  


The Brasiella tiger beetle fauna on Hispaniola, the second largest island of the Greater Antilles, has more species diversity than currently recognized as all populations previously have been assigned to the insular endemic Brasiella dominicana (Mandl). A comparative study of adult morphology, particularly male genitalic and female abdominal characters, for available Brasiella specimens from populations on Hispaniola, proposes eight additional new species also endemic to this island. Except for three sympatric species in the Sierra de Baoruco in southern Dominican Republic occurring in different habitats, all the Brasiella on Hispaniola appear to be allopatric. Most species occur in the major mountainous regions of Hispaniola. Two species, however, are known only from river floodplains in the southern coastal plain of the Dominican Republic. Brasiella dominicana (Mandl) and Brasiella ocoa, new species, occur along river floodplains emanating from the eastern end of the Cordillera Central in the Dominican Republic. Two new Brasiella species, Brasiella bellorum, and Brasiella philipi, occur in the Cordillera Central, Dominican Republic, the former species from central portions, and the latter species from north slopes of this mountain range, respectively. Three new Brasiella species, Brasiella rawlinsi, Brasiella iviei, and Brasiella youngi, are isolated in the Sierra de Baoruco, Dominican Republic, where each occupies a different habitat along an altitudinal gradient. The two new Brasiella species in Haiti are Brasiella darlingtoniana, in the Massif de la Selle, and Brasiella davidsoni, in the Massif de la Hotte. All nine Brasiella species on Hispaniola, along with Brasiella viridicollis (Dejean) and its two subspecies on Cuba, belong to the viridicollis species group of the genus Brasiella based on criteria presented in earlier published phylogenetic studies of Brazilian and West Indian tiger beetles. The subspecies Brasiella viridicollis fernandozayasi (Kippenhan, Ivie and Hopp) may represent a distinct species within this species group, whereas removal of Brasiella wickhami (W. Horn) from this species group seems warranted based on evidence presented. A general overview of species relationships for the Brasiella on Hispaniola are discussed, along with the current and ancestral geographic distributions of the Brasiella viridicollis species group in the West Indies. PMID:22371664

Acciavatti, Robert E



Development of a Cholera Vaccination Policy on the Island of Hispaniola, 2010-2013  

PubMed Central

Deployment of oral cholera vaccine (OCV) on the Island of Hispaniola has been considered since the emergence of the disease in October of 2010. At that time, emergency response focused on the time-tested measures of treatment to prevent deaths and sanitation to diminish transmission. Use of the limited amount of vaccine available in the global market was recommended for demonstration activities, which were carried out in 2012. As transmission continues, vaccination was recommended in Haiti as one component of a comprehensive initiative supported by an international coalition to eliminate cholera on the Island of Hispaniola. Leveraging its delivery to strengthen other cholera prevention measures and immunization services, a phased OCV introduction is pursued in accordance with global vaccine supply. Not mutually exclusive or sequential deployment options include routine immunization for children over the age of 1 year and campaigns in vulnerable metropolitan areas or rural areas with limited access to health services.

Vicari, Andrea S.; Ruiz-Matus, Cuauhtemoc; de Quadros, Ciro; Andrus, Jon K.



Significant earthquakes on the Enriquillo fault system, Hispaniola, 1500-2010: Implications for seismic hazard  

USGS Publications Warehouse

Historical records indicate frequent seismic activity along the north-east Caribbean plate boundary over the past 500 years, particularly on the island of Hispaniola. We use accounts of historical earthquakes to assign intensities and the intensity assignments for the 2010 Haiti earthquakes to derive an intensity attenuation relation for Hispaniola. The intensity assignments and the attenuation relation are used in a grid search to find source locations and magnitudes that best fit the intensity assignments. Here we describe a sequence of devastating earthquakes on the Enriquillo fault system in the eighteenth century. An intensity magnitude MI 6.6 earthquake in 1701 occurred near the location of the 2010 Haiti earthquake, and the accounts of the shaking in the 1701 earthquake are similar to those of the 2010 earthquake. A series of large earthquakes migrating from east to west started with the 18 October 1751 MI 7.4–7.5 earthquake, probably located near the eastern end of the fault in the Dominican Republic, followed by the 21 November 1751 MI 6.6 earthquake near Port-au-Prince, Haiti, and the 3 June 1770 MI 7.5 earthquake west of the 2010 earthquake rupture. The 2010 Haiti earthquake may mark the beginning of a new cycle of large earthquakes on the Enriquillo fault system after 240 years of seismic quiescence. The entire Enriquillo fault system appears to be seismically active; Haiti and the Dominican Republic should prepare for future devastating earthquakes.

Bakun, William H.; Flores, Claudia H.; ten Brink, Uri S.



Plume mantle source heterogeneity through time: Insights from the Duarte Complex, Hispaniola, northeastern Caribbean  

NASA Astrophysics Data System (ADS)

Located in the Cordillera Central of Hispaniola, the Duarte Complex offers an opportunity to study an on-land fragment of the Caribbean-Colombian oceanic plateau. Geochemical, Sr-Nd isotope, and 40Ar-39Ar radiometric age data combined with detailed mapping have shown that the Duarte Complex includes two lithostratigraphic units, composed of four geochemical groups of metavolcanic rocks: Group Ia, low-Ti high-Mg basalts, and group Ib, high-Ti picrites and primitive high-Mg basalts, occur interlayered in the lowermost levels of the lower unit; group II, light rare earth element (LREE)-enriched picrites, ferropicrites and high-Mg basalts, forms the main lava sequence of the lower unit; and group III, LREE-enriched Fe-Ti basalts, is present exclusively in the upper unit. Nd isotope and incompatible trace element patterns are diverse in the Duarte Complex metavolcanics and are consistent with mantle sources related to a heterogeneous plume. Mantle melt modeling suggests that an early, extensive melting (10-20%) of shallow mantle resulted in the formation of relatively depleted group I and II magmas, whereas the late, more enriched group III magmas were the product of deeper, low-degree (<3%) melting of a heterogeneous plume. Therefore plume mantle sources were more enriched and deeper through time. Foliated amphibolites of the Duarte Complex yield 40Ar-39Ar hornblende plateau ages of 93.9 ± 1.4 and 95.8 ± 1.9 Ma (Cenomanian, 99.6-93.5 Ma) that demonstrate an older age of the protholiths, probably Albian (>96 Ma). Hence an Early Cretaceous phase of the Caribbean-Colombian oceanic plateau construction is recorded in Hispaniola.

Escuder-Viruete, Javier; PéRez-Estaún, AndréS.; Contreras, Fernando; Joubert, Marc; Weis, Dominique; Ullrich, Thomas D.; Spadea, Piera



Accretionary margin of north-western Hispaniola: morphology, structure and development of part of the northern Caribbean plate boundary  

USGS Publications Warehouse

Broad-range side-scan sonar (GLORIA) images and single- and multi-channel seismic reflection profiles demonstrate that the margin of north-western Hispaniola has experienced compression as a consequence of oblique North American-Caribbean plate convergence. Two principal morphological or structural types of accretionary wedges are observed along this margin. The first type is characterized by a gently sloping (???4??) sea floor and generally margin-parallel linear sets of sea-floor ridges that gradually deepen towards the flat Hispaniola Basin floor to the north. The ridges are caused by an internal structure consisting of broad anticlines bounded by thrust faults that dip southwards beneath Hispaniola. Anticlines form at the base of the slope and are eventually sheared and underthrust beneath the slope. In contrast, the second type of accretionary wedge exhibits a steeper (???6-16??) sea-floor slope characterized by local slumping and a more abrupt morphological transition to the adjacent basin. The internal structure appears chaotic on seismic reflection profiles and probably consists of tight folds and closely spaced faults. We suggest that changes in sea-floor declivity and internal structure may result from variations in the dip or frictional resistance of the de??collement, or possibly from changes in the cohesive strength of the wedge sediments. The observed pattern of thickening of Hispaniola Basin turbidites towards the insular margin suggests differential southwards tilting of the Hispaniola Basin strata, probably in response to North America-Caribbean plate interactions since the Early Tertiary. Based upon indirect age control from adjacent parts of the northern caribbean plate boundary, we infer a Late Eocene to Early Miocene episode of transcurrent motion (i.e. little or no tilting), an Early Miocene to Late Pliocene period of oblique convergence (i.e. increased tilt) during which the accretionary wedge began to be constructed, and a Late Pliocene to Recent episode of increased convergence (i.e. twice the Miocene to Pliocene tilt), which has led to rapid uplift and erosion of sediment sources on the margin and on Hispaniola, generating a submarine fan at the base of the insular slope. ?? 1992.

Dillon, W. P.; Austin, Jr. , J. A.; Scanlon, K. M.; Terence, Edgar, N.; Parson, L. M.



MultiChannel Seismic Images of Neogene Rifting in the Northern Mona Passage Between Puerto Rico and Hispaniola  

Microsoft Academic Search

Highly oblique (70°) convergence is occurring along the northeastern North America-Caribbean plate boundary offshore northern Puerto Rico and the Virgin Islands. Complicating the tectonic setting is the oblique collision of the 20 km-thick SE Bahamas carbonate platform that impedes the northeasterly movement of Hispaniola, leaving Puerto Rico and the Virgin Islands to separate along north-trending extensional structures in the Mona

S. A. Mondziel; N. R. Grindlay; P. Mann; A. Escalona



Investigating the relationship between deforestation and changes in hydrology across the island of Hispaniola  

NASA Astrophysics Data System (ADS)

Over recent decades, Haiti and the Dominican Republic have reported changes in reservoir water levels - while some areas have experienced increases others have seen decreasing trends, especially reservoirs located in the Dominican Republic - leading to, among other things, regional flooding and shortages in hydroelectricity output. We investigate whether extensive deforestation, particularly in the western part of Hispaniola - shared by the two nations - is driving these changes by affecting the regional water balance. Due to a lack of available spatiotemporal environmental data, remotely sensed vegetation and precipitation information is used along with estimated evapotranspiration rates to study regional hydro-climatologic fluctuations over three decades. Changes in vegetative cover, precipitation, and evapotranspiration across the island are investigated using 25 years of Normalized Difference Vegetation Index (NDVI) data, historical satellite and gauge precipitation records, and estimated surface temperature and solar radiation. NDVI values are derived from imagery obtained by NOAA's 8 km resolution AVHRR instrument. Monthly precipitation is collected from several different sources, including NASA and NOAA precipitation satellites, as well as local rain gauges. Evapotranspiration is estimated using an energy balance approach. Preliminary results indicate a general decrease in rainfall over the eastern part of the island during the past three decades, with little change observed across the western half. NDVI and precipitation anomalies across the island are not well correlated, suggesting that deforestation is likely not the cause of regional changes in precipitation. The results of this work hold potentially important implications for future land-use and water infrastructure planning for both nations.

Hakimdavar, R.



Frequency-dependent attenuation of the Hispaniola Island region of the Caribbean Sea  

USGS Publications Warehouse

We determine frequency-dependent attenuation 1/Q(f) for the Hispaniola region using direct S and Lg waves over five distinct passbands from 0.5 to 16 Hz. Data consist of 832 high-quality vertical and horizontal component waveforms recorded on short-period and broadband seismometers from the devastating 12 January 2010 M 7.0 Haiti earthquake and the rich sequence of aftershocks. For the distance range 250–700 km, we estimate an average frequency-dependent Q(f)=224(±27)f0.64(±0.073) using horizontal components of motion and note that Q(f) estimated with Lg at regional distances is very consistent across vertical and horizontal components. We also determine a Q(f)=142(±21)f0.71(±0.11) for direct S waves at local distances, ?100 km. The strong attenuation observed on both vertical and horizontal components of motion is consistent with expectations for a tectonically active region.

McNamara, D.; Meremonte, M.; Maharrey, J. Z.; Mildore, S-L.; Altidore, J. R.; Anglade, D.; Hough, S. E.; Given, D.; Benz, H.; Gee, L.; Frankel, A.



Influence of Salinity and Temperature on the Physiology of Limia melanonotata (Cyprinodontiformes: Poeciliidae): A Search for Abiotic Factors Limiting Insular Distribution in Hispaniola  

Microsoft Academic Search

We investigated salinity and temperature effects on routine metabolic rate (RMR), tempera- ture tolerance (CTMax, critical thermal maximum), and salinity toleranc eo fLimia melanonotata, a poeciliid fish that occurs in west-central inland waters of Hispaniola. Routine metabolic rate and CTMax were mea- sured in fish acclimated to three salinities (0, 30, and 60 ppt) and temperatures (25°, 30°, and 35°C)



New myrmecomorphous longhorned beetles from Haiti and the Dominican Republic with a key to Anaglyptini and Tillomorphini of Hispaniola (Coleoptera, Cerambycidae, Cerambycinae)  

PubMed Central

Abstract First records of the tribes Anaglyptini and Tillomorphini (Coleoptera: Cerambycidae: Cerambycinae) are documented for Hispaniola. A new genus of a highly myrmecomorphic longhorned beetle (Licracantha gen. n.) is described and illustrated based on one species (Licracantha formicaria sp. n.) and provisionally assigned to Tillomorphini. Three other new species of ant mimic longhorned beetles are described and illustrated: Calliclytus macoris sp. n. (Tillomorphini), Tilloclytus baoruco sp. n., and Tilloclytus neiba sp. n. (Anaglyptini). An identification key and distribution map to all known Hispaniolan species of these two tribes are presented.

Lingafelter, Steven W.



Analysis of rhizobial strains nodulating Phaseolus vulgaris from Hispaniola Island, a geographic bridge between Meso and South America and the first historical link with Europe.  


Hispaniola Island was the first stopover in the travels of Columbus between America and Spain, and played a crucial role in the exchange of Phaseolus vulgaris seeds and their endosymbionts. The analysis of recA and atpD genes from strains nodulating this legume in coastal and inner regions of Hispaniola Island showed that they were almost identical to those of the American strains CIAT 652, Ch24-10 and CNPAF512, which were initially named as Rhizobium etli and have been recently reclassified into Rhizobium phaseoli after the analysis of their genomes. Therefore, the species R. phaseoli is more abundant in America than previously thought, and since the proposal of the American origin of R. etli was based on the analysis of several strains that are currently known to be R. phaseoli, it can be concluded that both species have an American origin coevolving with their host in its distribution centres. The analysis of the symbiovar phaseoli nodC gene alleles carried by different species isolated in American and European countries suggested a Mesoamerican origin of the ? allele and an Andean origin of the ? allele, which is supported by the dominance of this latter allele in Europe where mostly Andean cultivars of common beans have been traditionally cultivated. PMID:24239274

Díaz-Alcántara, César-Antonio; Ramírez-Bahena, Martha-Helena; Mulas, Daniel; García-Fraile, Paula; Gómez-Moriano, Alicia; Peix, Alvaro; Velázquez, Encarna; González-Andrés, Fernando



Overthrusting versus subduction beneath southern Hispaniola  

NASA Astrophysics Data System (ADS)

Recent observations of the deformational features on the Muertos compressive margin together with sandbox kinematic and gravity modeling question the hypothesized subduction of the Caribbean plate's interior beneath the eastern Greater Antilles island arc. With the aim of testing such subduction, we carried out a wide-angle seismic transect across the widest part of the Muertos compressive margin (longitude 69°W) in the spring of 2009. Shots were fired along the 200 km transect every 90 seconds from the R/V Hesperides' 3850 cubic inches water-gun array, which, towed at 5 knots, resulted in a shot spacing of ~ 230 m. The seismic signal was recorded by five ocean-bottom seismometers deployed at distance intervals from 30 to 50 km. Adjacent reprocessed reflection seismic lines and previous works provided an initial model of the sediment column and the geometry of upper crustal reflectors. A 2-D forward ray-tracing model of the wide-angle transect outlines the broad-scale crustal structure across the Muertos margin. The Caribbean oceanic slab is imaged underneath the Muertos margin to about 50 km north of the deformation front and up to 19 km depth. A change in crustal p-wave velocity at ~60 km from the deformation front is interpreted to be the boundary between the arc crust and the compressive deformed belt. The Caribbean oceanic crust is not seen extending farther north. Results from gravity modeling using ship data acquired on the seismic profile corroborate a model of an overthrusted Caribbean oceanic slab extending a few tens of km northward from the compressive deformation front and rejects a subduction process, independently of the geometry of the slab used or its angle. In addition to the seismic experiment and the gravity modeling, vertical cross-sections of p-wave global tomography do not show northward inclination of a fast velocity layer into the upper mantle suggesting that the Caribbean plate's interior does not subduct under the Muertos margin. Overall, our results indicate limited thrusting of the island arc over the Caribbean plate's interior rather than subduction of the Caribbean oceanic slab beneath the island arc at the Muertos margin as it has been hypothesized for the last 30 years.

Llanes Estrada, M.; Carbó-Gorosabel, A.; ten Brink, U. S.; Granja Bruña, J.; Flores, C. H.; Villasenor, A.; Davila, J. M.; Pazos, A.



From intra-oceanic subduction to arc accretion and arc-continent collision: Insights from the structural evolution of the Río San Juan metamorphic complex, northern Hispaniola  

NASA Astrophysics Data System (ADS)

The Río San Juan metamorphic complex exposes a segment of a high-pressure subduction-accretionary complex built during Caribbean island arc-North America continental margin convergence. It is composed of accreted arc- and oceanic-derived metaigneous rocks, serpentinized peridotites and minor metasediments forming a structural pile. Combined detailed mapping, structural and metamorphic analysis, and geochronology show that the deformation can be divided into five main events (D1-D5). An early subduction-related D1 deformation and M1 metamorphism produced greenschist (mafic rocks of the Gaspar Hernández peridotite-tectonite), blueschist and eclogite (metamafic blocks in the Jagua Clara mélange), high-P epidote-amphibolite and eclogite (Cuaba unit), and lower blueschist and greenschist-facies conditions (Morrito unit). This was followed by M2 decompression and cooling in the blueschist, greenschist and low-P amphibolite-facies conditions. The shape of the retrograde P-T path, the age of the exhumation-related D2 structures, and the tectonic significance of D2 deformation are different in each structural unit. Published U-Pb and 40Ar/39Ar plateau ages and T-t/P-t estimations reveal diachronic Turonian-Coniacian to Maastrichtian retrograde M2 metamorphism in the different structural units of the complex, during a consistent D2 top-to-the-NE/ENE tectonic transport. Regionally, a similar top-to-the-ENE tectonic transport also took place in the metasedimentary nappes of the Samaná complex during the Eocene to earliest Miocene. This kinematic compatibility indicates a general northeastward progradation of deformation in the northern Caribbean convergent margin, as the successive tectonic incorporation of arc, oceanic and continental-derived terrains to the developing Caribbean subduction-accretionary complex took place. D3-D5 deformations are discontinuous and much less penetrative, recording the evolution from ductile to brittle conditions of deformation in the complex. The D3 event substantially modified the nappe-stack and produced open folds with amplitudes up to kilometer-scale. The Late Paleocene-Eocene D4 structures are ductile to ductile-brittle thrusts and inverse shear bands. D5 is a Tertiary, entirely brittle deformation that had considerable influence in the geometry of the whole complex. From the Miocene to the Present, it has been cut and laterally displaced by a D5 sinistral strike-slip fault system associated with the Septentrional fault zone.

Escuder-Viruete, Javier; Valverde-Vaquero, Pablo; Rojas-Agramonte, Yamirka; Jabites, Janet; Pérez-Estaún, Andrés



Seismic Images of the Crust across the northern Beata Ridge (NE Caribbean)  

Microsoft Academic Search

The Beata Ridge is a NE-SW trending structure located in the interior of the Caribbean plate, between the extended Colombian and Venezuelan basins. The northern part of the ridge is ~100 km-wide and emerged (Sierra de Bahoruco in the southern Hispaniola Island) and the southern part is ~3500 km- wide and > 4000 m below sea level. It has been

Diana Nuñez; Diego Córdoba; Antonio Pazos; José Martín-Dávila; Andrés. Carbó; José Luis Granja-Bruña; Juan Payero; Mario Octavio Cotilla



Hope for Haiti: An analysis of Facebook and Twitter usage during the earthquake relief efforts  

Microsoft Academic Search

The Haitian earthquake devastated the small island of Hispaniola, leaving thousands dead and billions of dollars in property damage. The earthquake also ignited a firestorm of social media use by organizations. By applying framing theory to the analysis of Facebook posts and tweets sent by nonprofits and media organizations, this study discovered differences between nonprofits and media in terms of

Sidharth Muralidharan; Leslie Rasmussen; Daniel Patterson; Jae-Hwa Shin




Microsoft Academic Search

The Columbus Caravels Project is a multi-phase research program designed to locate and excavate from St. Ann's Bay, Jamaica the remains of Columbus' last two ships, Capitana and Santiago de Palos. After an enforced exile of a year and five days, Columbus and his marooned crew were finally rescued on 29 June 1504. They departed for Hispaniola and Spain, leaving

Stephan A. Schwartzi; Randall J. De Matteiii; Roger C. Smithiii


Systematics, Biogeography and Leaf Anatomy and Architecture of Bursera subgen. Bursera (Burseraceae) in the Greater Antilles and the Bahamas  

Microsoft Academic Search

This dissertation presents a comprehensive study on the origin and evolutionary relationships of the species of Bursera in Cuba, Hispaniola, Jamaica and the Bahamas. The goals of the first chapter were to test monophyly of the group, revisit a recent transfer of two species of Bursera to Commiphora, and place recently discovered mainland species using the reconstructed phylogenies. Additionally, divergence

María Cristina Martínez-Habibe



Project Flood Data Report Collected in the Caribbean Sea, August 1967 to August 1968.  

National Technical Information Service (NTIS)

Mine divisions 41, 45, and 85 collected oceanographic data in the Caribbean Sea from August 1967 to August 1968 in support of project Flood. Most of the data were collected in the vicinities of Hispaniola, Puerto Rico, and the Virgin Islands. (Author)

A. S. Barwick



NASA Imagery of Haiti  

NSDL National Science Digital Library

This page includes a collection of NASA images surrounding the Haiti Earthquake. Images include landslide risk maps, photos from the Terra Spacecraft, post-earthquake Port au Prince, Hispaniola topography map, anaglyph (3-D) map of southern Haiti, and 3-D topography of Port au Prince.



Oblique collision in the northeastern Caribbean from GPS measurements and geological observations  

Microsoft Academic Search

Previous Caribbean GPS studies have shown that the rigid interior of the Caribbean plate is moving east-northeastward (070°) at a rate of 18-20 +\\/- 3 mm\\/yr relative to North America. This direction implies maximum oblique convergence between the island of Hispaniola on the Caribbean plate and the 22-27-km-thick crust of the Bahama carbonate platform on the adjacent North America plate.

Paul Mann; Eric Calais; Jean-Claude Ruegg; Charles DeMets; Pamela E. Jansma; Glen S. Mattioli



Neotectonics of Puerto Rico and the Virgin Islands, northeastern Caribbean, from GPS geodesy  

Microsoft Academic Search

The boundary between the North American and Caribbean plates is characterized primarily by left-lateral motion along predominantly east-west striking faults. Seismicity and marine geophysical survey data are consistent with at least two, and possibly three, microplates in the diffuse boundary zone in the northeastern Caribbean: (1) the Gonave, (2) the Hispaniola, and (3) the Puerto Rico-northern Virgin Islands (PRVI). We

Pamela E. Jansma; Glen S. Mattioli; Alberto Lopez; Charles DeMets; Timothy H. Dixon; Paul Mann; Eric Calais



Travel Health Alert Notices and Haiti cholera outbreak, Florida, USA, 2011.  


To enhance the timeliness of medical evaluation for cholera-like illness during the 2011 cholera outbreak in Hispaniola, printed Travel Health Alert Notices (T-HANs) were distributed to travelers from Haiti to the United States. Evaluation of the T-HANs’ influence on travelers’ health care–seeking behavior suggested T-HANs might positively influence health care–seeking behavior. PMID:22204040

Selent, Monica U; McWhorter, Amanda; De Rochars, Valery M Beau; Myers, Rebecca; Hunter, David W; Brown, Clive M; Cohen, Nicole J; Molinari, Noelle A; Warwar, Kirsten; Robbins, Danisha; Heiman, Katherine E; Newton, Anna E; Schmitz, Ann; Oraze, Michael J; Marano, Nina



Deformation partitioning at the junction between the Enriquillo fault and the Trans-Haitian belt  

Microsoft Academic Search

The recent Haiti earthquake, although it ruptured dramatically the strike-slip Enriquillo Plantain Garden Fault Zone (EPGFZ), is actually located where this fault cross-cut or is overlapped by the frontal part of the Trans-Haitian belt accretionary wedge. This belt started accreting flysch series in the North of Hispaniola during the late Palaeogene and propagated onto the carbonate platform during the Miocene

S. Leroy; M. Pubellier; N. Ellouz; R. Momplaisir; D. Boisson; H. Amilcar



Neotectonics of a subduction/strike-slip transition: the northeastern Dominican Republic  

SciTech Connect

The Septentrional fault system in the northeastern Dominican Republic marks the zone where the North American-Carribean plate boundary is evolving from subduction to strike-slip motion, and where terranes appear to be forming and migrating laterally in a subduction complex/forearc region. On the Island of Hispaniola, slip vectors are oblique to the strike of the Puerto Rico trench, and oblique subduction thrusts the upper plate over normal seafloor. The offshore geology and seismicity of the northern Caribbean suggest that uplift, broad crustal warping, thrusting, and strike-slip faulting (ie. collisional tectonics) should be present in the northern part of the Dominican Republic. The high topography (>1000m), high levels of seismicity, and large earthquakes support the hypothesis of contemporary deformation in Hispaniola. In this region, the subduction regime dies out toward the west, and deformation is transferred to onshore, oblique-slip faults. As this change in tectonic style has occurred in Neogene to Recent times, we are investigating the modern evolution of a plate boundary. We have already documented: (1) the presence of a strike-slip faulting in the northeastern Dominican Republic; (2) an anomalous push-up structure; and (3) a region of numerous splay faults. In conclusion, recent seismicity suggest a wide zone of deformation and variations in interplate motions near Hispaniola. This island lies at the western limit of active underthrusting and at the eastern limit of onshore faulting, i.e., at an important transition from a subduction to strike-slip regime.

Winslow, M.A.; McCann, W.R.



Re-emergence of Cholera in the Americas: Risks, Susceptibility, and Ecology  

PubMed Central

Background: The re-emergence of cholera in Haiti has established a new reservoir for the seventh cholera pandemic which threatens to spread to other countries in the Americas. Materials and Methods: Statistics from this new epidemic are compared to the 1991 Peru epidemic, which demonstrated the speed and complexity with which this disease can spread from country to country. Environmental factors implicated in the spread of Vibrio cholerae such as ocean currents and temperatures, as well as biotic factors from zooplankton to waterfowl pose a risk for many countries in the Americas. Results: The movement of people and goods from Hispaniola are mostly destined for North America, but occur to some degree throughout the Americas. These modes of transmission, and the probability of uncontrolled community spread beyond Hispaniola, however, are completely dependent upon risk factors within these countries such as water quality and availability of sanitation. Although North America has excellent coverage of these deterrents to the spread of infectious gastrointestinal diseases, many countries throughout Latin America and the Caribbean lack these basic services and infrastructures. Conclusions: In order to curb the immediate spread of cholera in Hispaniola, treatment availability should be expanded to all parts of the island and phase II epidemic management initiatives must be developed.

Poirier, Mathieu JP; Izurieta, Ricardo; Malavade, Sharad S; McDonald, Michael D



Late Cenozoic alkaline volcanism in the northwestern Caribbean - Tectonic setting and Sr isotopic characteristics  

NASA Technical Reports Server (NTRS)

The northwestern corner of the Caribbean plate has at least sixteen centers of alkalic volcanism, most of which is Quaternary in age. Sr-87/Sr-86 ratios of the rocks in these centers are used to distinguish three geographical groups: a low-ratio group (0.7026-0.7031) at the Nicaraguan Rise, an intermediate-ratio group (0.7036-0.7038) in northeastern Costa Rica, and a high-ratio group (0.7047-0.7063) in Hispaniola. It is suggested that the increased radiogenic strontium in both Costa Rica and Hispaniola may have come from volatile-rich fluids escaping from adjacent subducting slabs of oceanic crust. The isotopic differences between the two areas is explained by the relative longevity and high rate of subduction in Costa Rica compared to that in Hispaniola. The Costa Rican alkaline rocks cover a segment of the Cocos plate which is being subducted at a smaller angle (about 35 deg) than at the rest of the Central American arc.

Wadge, G.; Wooden, J. L.



Stress interaction between subduction earthquakes and forearc strike-slip faults: Modeling and application to the northern Caribbean plate boundary  

USGS Publications Warehouse

Strike-slip faults in the forearc region of a subduction zone often present significant seismic hazard because of their proximity to population centers. We explore the interaction between thrust events on the subduction interface and strike-slip faults within the forearc region using three-dimensional models of static Coulomb stress change. Model results reveal that subduction earthquakes with slip vectors subparallel to the trench axis enhance the Coulomb stress on strike-slip faults adjacent to the trench but reduce the stress on faults farther back in the forearc region. In contrast, subduction events with slip vectors perpendicular to the trench axis enhance the Coulomb stress on strike-slip faults farther back in the forearc, while reducing the stress adjacent to the trench. A significant contribution to Coulomb stress increase on strike-slip faults in the back region of the forearc comes from "unclamping" of the fault, i.e., reduction in normal stress due to thrust motion on the subduction interface. We argue that although Coulomb stress changes from individual subduction earthquakes are ephemeral, their cumulative effects on the pattern of lithosphere deformation in the forearc region are significant. We use the Coulomb stress models to explain the contrasting deformation pattern between two adjacent segments of the Caribbean subduction zone. Subduction earthquakes with slip vectors nearly perpendicular to the Caribbean trench axis is dominant in the Hispaniola segment, where the strike-slip faults are more than 60 km inland from the trench. In contrast, subduction slip motion is nearly parallel to the Caribbean trench axis along the Puerto Rico segment, where the strike-slip fault is less than 15 km from the trench. This observed jump from a strike-slip fault close to the trench axis in the Puerto Rico segment to the inland faults in Hispaniola is explained by different distributions of Coulomb stress in the forearc region of the two segments, as a result of the change from the nearly trench parallel slip on the Puerto Rico subduction interface to the more perpendicular subduction slip beneath Hispaniola. The observations and modeling suggest that subduction-induced strike-slip seismic hazard to Puerto Rico may be smaller than previously assumed but the hazard to Hispaniola remains high. Copyright 2004 by the American Geophysical Union.

ten, Brink, U.; Lin, J.



VIROLOGY: Poliomyelitis Eradication--a Dangerous Endgame  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. Efforts to eradicate poliovirus from the face of the Earth have been very successful, thanks in large part to the oral poliovirus vaccine developed by Albert Sabin. However, as Nathanson and Fine explain in their Perspective, maintaining a world free from poliomyelitis will not be easy. They discuss the implications of a recent outbreak of paralytic poliomyelitis on the island of Hispaniola from which wild poliovirus was eliminated 10 years previously (Kew et al.).

Neal Nathanson (University of Pennsylvania;Departments of Microbiology and Neurology); Paul Fine (University of Pennsylvania;Departments of Microbiology and Neurology)



STS-65 Earth observation of Port-Au-Prince, Haiti, was taken aboard OV-102  

NASA Technical Reports Server (NTRS)

STS-65 Earth observation taken aboard Columbia, Orbiter Vehicle (OV) 102, is of Port-Au-Prince, Haiti. This view, centered at approximately 18.5 degrees north and 72.5 degrees west, shows the location of the city of Port-Au-Prince. It is located at the head of Port-Au-Prince Bay in a valley. The Eastern edge of Saumatre Lake, visible in the photograph, forms the boundary with the Dominican Republic. The Haitian Republic occupies the western portion of the Island of Hispaniola.



Epidemic risk from cholera introductions into Mexico.  


Stemming from the 2010 cholera outbreak in Haiti, cholera transmission in Hispaniola continues with over 40,000 cases in 2013. The presence of an ongoing cholera outbreak in the region poses substantial risks to countries throughout the Americas, particularly in areas with poor infrastructure. Since September 9, 2013 nearly 200 cholera cases have been reported in Mexico, as a result of introductions from Hispaniola or Cuba. There appear to have been multiple introductions into Mexico resulting in outbreaks of 2 to over 150 people. Using publicly available data, we attempt to estimate the reproductive number (R) of cholera in Mexico, and thereby assess the potential of continued introductions to establish a sustained epidemic. We estimate R for cholera in Mexico to be between 0.8 to 1.1, depending on the number of introductions, with the confidence intervals for the most plausible estimates crossing 1. These results suggest that the efficiency of cholera transmission in some regions of Mexico is near that necessary for a large epidemic. Intensive surveillance, evaluation of water and sanitation infrastructure, and planning for rapid response are warranted steps to avoid potential large epidemics in the region. PMID:24600536

Moore, Sean M; Shannon, Kerry L; Zelaya, Carla E; Azman, Andrew S; Lessler, Justin



Early tectonic history of the Greater Antilles  

SciTech Connect

The islands of the Greater Antilles exhibit differing pre-Oligocene tectonic styles and histories, but all display the results of convergent plate activity from the Early Cretaceous to the Middle Eocene. Western and central Cuba consist of autochthonous, Jurassic and older continental crust, which was overthrust by Cretaceous ophiolites in the Early to Middle Eocene. In contrast, eastern Cuba seems to be similar to Northern Hispaniola, and both areas consist of complexes of upper Cretaceous to Eocene magmatic-arc rocks, and trench generated ophiolites and blueschists produced by SW directed subduction. The oldest rocks in central Hispaniola are exposed in NW trending linear fault-bounded belts. Unusual high-Mg greenschists and amphibolites, quartz-feldspathic greenschists, together with N-type MORB basalts and keratophyric volcanics, are juxtaposed against a medial serpentinite belt. Central and eastern Puerto Rico consist of Lower to Upper Cretaceous volcanic rocks intruded by upper Cretaceous to Eocene plutons. Similar Cretaceous volcanics occur in SW Puerto Rico, but they are overthrust by Upper Jurassic cherts, spilites and amphibolites. Jamaica lies along the Nicaraguan Rise to the SW of the other islands and consists of Barremian to Maastrichtian volcanics and volcanogenic sediments intruded by upper Cretaceous calc-alkalic plutons. Blueschists and related rocks in eastern Jamaica, and geochemical zonation in the igneous rocks suggest that the subduction was to the NW. Change in tectonic movements from convergence to left lateral shear took place during the Late Eocene/Early Oligocene.

Lewis, J.F.; Draper, G.; Mattson, P.



Collisional zones in Puerto Rico  

NASA Astrophysics Data System (ADS)

Collisional events along the North American-Caribbean plate boundary are complex and not completely understood. Structures and metamorphism in rocks exposed in Cuba, Hispaniola, and Puerto Rico suggest that the margin has undergone at least three main contractional events in the Early Cretaceous, Late Cretaceous, and in the Late Eocene. The Eocene event is more evident in the transpressional structures preserved in Eocene rocks and may be related to the oblique collision of the northern margin of the Caribbean Plate with continental crust of the Bahamas in the North American Plate. In Puerto Rico, the Late Eocene collisional event is best exposed in the Northern Puerto Rico Fault Zone (NPRFZ) and the Southern Puerto Rico Fault Zone (SPRFZ). These fault zones show transpression in Eocene rocks that suggest contraction and left-lateral shear. The NPRFZ is the boundary between the Northeast and Southwest blocks. Its main fault is the Cerro Mula Fault, a WNW-ESE striking left-lateral fault. The SPRFZ separates the Central and Southwest blocks and strikes NW-SE in the western part of the island. The origin and extent of the Early Cretaceous and Late Cretaceous events are less clear. Recent structural and stratigraphic studies in the Southwest block of Puerto Rico suggest that deformation of Late Cretaceous folded and faulted sedimentary and volcanic rocks, and thrust emplacement of mantle rocks (serpentinized-peridotite) onto the crust are related to Maastrichtian to Paleocene contraction along the plate boundary. In Puerto Rico, there is no metamorphism associated to this event. This deformation constitutes a Late Cretaceous collisional event that is also recognized in Hispaniola and Cuba. Late Cretaceous-Paleocene serpentinite emplacement is attributed to the collision of the subduction zone with the hypothesized Caribeana submerged platform to the north. In Puerto Rico there is a volcanic hiatus in Early Paleocene that may be related to the proposed collision. Reactivation of these structures occurred during Late Eocene-Early Oligocene. The Early Cretaceous tectonic event in Puerto Rico is deduced from stratigraphic relationships of the serpentinite and Late Cretaceous rocks. Early contraction in Cuba and Hispaniola may be related to increased convergence along a subduction zone. However, the characteristics of the tectonic event are not understood. In spite of the temporal similarities of deformation in the northern Caribbean, there are noted differences in the type of deformation that may be related to variations in shape and orientation of pre-existing zones of weaknesses and geographic locations along the Caribbean-North American plate boundary.

Lao Davila, D. A.



Seismic hazard maps for Haiti  

USGS Publications Warehouse

We have produced probabilistic seismic hazard maps of Haiti for peak ground acceleration and response spectral accelerations that include the hazard from the major crustal faults, subduction zones, and background earthquakes. The hazard from the Enriquillo-Plantain Garden, Septentrional, and Matheux-Neiba fault zones was estimated using fault slip rates determined from GPS measurements. The hazard from the subduction zones along the northern and southeastern coasts of Hispaniola was calculated from slip rates derived from GPS data and the overall plate motion. Hazard maps were made for a firm-rock site condition and for a grid of shallow shear-wave velocities estimated from topographic slope. The maps show substantial hazard throughout Haiti, with the highest hazard in Haiti along the Enriquillo-Plantain Garden and Septentrional fault zones. The Matheux-Neiba Fault exhibits high hazard in the maps for 2% probability of exceedance in 50 years, although its slip rate is poorly constrained.

Frankel, Arthur; Harmsen, Stephen; Mueller, Charles; Calais, Eric; Haase, Jennifer



Eremonidiopsis aggregata, gen. n., sp. n. from Cuba, the third West Indian Dioptinae (Lepidoptera, Notodontidae).  


A new genus and species of Dioptinae (Lepidoptera, Noctuoidea, Notodontidae) is described from Cuba, this being the third taxon of the subfamily known from the West Indies. Eremonidiopsis aggregata, gen. n., sp. n., appears to be closely related to Eremonidia mirifica Rawlins & Miller from Hispaniola among members of the tribe Dioptini. Eremonidiopsis aggregata is known from two localities in the middle and western portions of the northeastern Cuban mountain range, Nipe-Sagua-Baracoa. The species inhabits low elevations (300-400 m) covered by lowland rainforest and sclerophyll rainforest. The six known specimens, all males, were part of small swarms flying near the top of an unidentified tree during the day at both collecting sites. These localities are included within protected areas, the "Pico Cristal" National Park in the West and the "Alexander von Humbolt" National Park in the East. PMID:24146561

Aguila, Rayner Núñez



An extinct monkey from Haiti and the origins of the Greater Antillean primates  

PubMed Central

A new extinct Late Quaternary platyrrhine from Haiti, Insulacebus toussaintiana, is described here from the most complete Caribbean subfossil primate dentition yet recorded, demonstrating the likely coexistence of two primate species on Hispaniola. Like other Caribbean platyrrhines, I. toussaintiana exhibits primitive features resembling early Middle Miocene Patagonian fossils, reflecting an early derivation before the Amazonian community of modern New World anthropoids was configured. This, in combination with the young age of the fossils, provides a unique opportunity to examine a different parallel radiation of platyrrhines that survived into modern times, but is only distantly related to extant mainland forms. Their ecological novelty is indicated by their unique dental proportions, and by their relatively large estimated body weights, possibly an island effect, which places the group in a size class not exploited by mainland South American monkeys. Several features tie the new species to the extinct Jamaican monkey Xenothrix mcgregori, perhaps providing additional evidence for an inter-Antillean clade.

Cooke, Siobhan B.; Rosenberger, Alfred L.; Turvey, Samuel



Petroleum in the Caribbean Basin: Further exploration justified?  

SciTech Connect

After more than half a century of exploration for petroleum in that part of the Caribbean Basin covered by this review, the prospects for substantial discoveries remain low. Only Barbados has had modest but sustained production of oil and gas. In Hispaniola minor production from small prospects lasted briefly. Exploration in the northeast Caribbean has not resulted in discoveries. Similar exploration in Puerto Rico and, on a more extensive scale, in Jamaica, has also failed to show positive results. On the Nicaragua Rise (Mosquitia, Tela Basins) drilling has produced shows but no production, a situation also evident in Belize. Nevertheless, examination of these results, in the context of the regional geology of the Caribbean Basin, suggests there are areas where further exploration is justified.

Robinson, E. [Univ. of the West Indies, Kingston (Jamaica)



Documentation for Initial Seismic Hazard Maps for Haiti  

USGS Publications Warehouse

In response to the urgent need for earthquake-hazard information after the tragic disaster caused by the moment magnitude (M) 7.0 January 12, 2010, earthquake, we have constructed initial probabilistic seismic hazard maps for Haiti. These maps are based on the current information we have on fault slip rates and historical and instrumental seismicity. These initial maps will be revised and improved as more data become available. In the short term, more extensive logic trees will be developed to better capture the uncertainty in key parameters. In the longer term, we will incorporate new information on fault parameters and previous large earthquakes obtained from geologic fieldwork. These seismic hazard maps are important for the management of the current crisis and the development of building codes and standards for the rebuilding effort. The boundary between the Caribbean and North American Plates in the Hispaniola region is a complex zone of deformation. The highly oblique ~20 mm/yr convergence between the two plates (DeMets and others, 2000) is partitioned between subduction zones off of the northern and southeastern coasts of Hispaniola and strike-slip faults that transect the northern and southern portions of the island. There are also thrust faults within the island that reflect the compressional component of motion caused by the geometry of the plate boundary. We follow the general methodology developed for the 1996 U.S. national seismic hazard maps and also as implemented in the 2002 and 2008 updates. This procedure consists of adding the seismic hazard calculated from crustal faults, subduction zones, and spatially smoothed seismicity for shallow earthquakes and Wadati-Benioff-zone earthquakes. Each one of these source classes will be described below. The lack of information on faults in Haiti requires many assumptions to be made. These assumptions will need to be revisited and reevaluated as more fieldwork and research are accomplished. We made two sets of maps using different assumptions about site conditions. One set of maps is for a firm-rock site condition (30-m averaged shear-wave velocity, Vs30, of 760 m/s). We also developed hazard maps that contain site amplification based on a grid of Vs30 values estimated from topographic slope. These maps take into account amplification from soils. We stress that these new maps are designed to quantify the hazard for Haiti; they do not consider all the sources of earthquake hazard that affect the Dominican Republic and therefore should not be considered as complete hazard maps for eastern Hispaniola. For example, we have not included hazard from earthquakes in the Mona Passage nor from large earthquakes on the subduction zone interface north of Puerto Rico. Furthermore, they do not capture all the earthquake hazards for eastern Cuba.

Frankel, Arthur; Harmsen, Stephen; Mueller, Charles; Calais, Eric; Haase, Jennifer



Airborne Radar Observations of Hurricane Georges during Landfall over the Dominican Republic  

NASA Technical Reports Server (NTRS)

On 22 September 1998 hurricane Georges made landfall on the Dominican Republic (DR). Georges cost the DR at least 500 lives, made more than 155,000 people homeless and caused extensive damage to the country's main industries, tourism and agriculture. There was considerable wind damage, with wind gusts up to 58 m/s in Santa Domingo on the south coast, but most of the damage and deaths resulted from mudslides and the flooding of rivers. While this may have been the worst natural disaster to strike the DR, the sustained rapid storm movement saved the island from worse damage. Georges had previously affected several islands in the Lesser Antilles and Puerto Rico, but it had retained much of its circulation strength. Forty raingauge stations across the DR measured rainfall totals from Georges between 0.7 and 41 cm, the latter at the capital Santo Domingo, located on the south coast. At Herrera the maximum 1 h rainfall rate was 72 mm/h. It is suspected that much higher rain rates occurred in DR's mountainous interior. Before landfall the eye was clearly evident in satellite imagery. When the eye moved over southeastern DR, it filled rapidly, and the cloud top height decreased in all storm sectors except in the southern inflow sector, where a long-lived MCS, with a diameter larger than that of the eyewall, slowly became enwrapped in the hurricane circulation. The eye closure was most rapid between 16-18 UTC, when the eyewall circulation felt the mountainous terrain of the Cordillera Central, which rises up to 3,093 m. The estimated central pressure increased from 962 hPa at 15 UTC to 986 hPa at 03Z on 23 Sept, and the maximum sustained surface wind speed decreased from 54 to 36 in s-1 during the same period. The island of Hispaniola has a cross-track width of about 250 km, much wider than the diameter of the eyewall anvil (about 100 km before landfall). So the event can truly be considered to be a landfalling case, even though Georges recovered after crossing Hispaniola, albeit never to the same strength. This talk will summarize satellite and ground observations of Georges, as it passed the DR, and it will focus on EDOP data. In particular, we will try to estimate the rainfall rate over the mountainous terrain of the DR. And we will use detailed sounding data to explain the presence and characteristics of the massive MCS to the south, as well as the upper-level updrafts apparent over this MCS and over the mountains of the DR.

Geerts, B.; Heymsfield, G.; Tian, L.



Genetic introgression and hybridization in Antillean freshwater turtles (Trachemys) revealed by coalescent analyses of mitochondrial and cloned nuclear markers.  


Determining whether a conflict between gene trees and species trees represents incomplete lineage sorting (ILS) or hybridization involving native and/or invasive species has implications for reconstructing evolutionary relationships and guiding conservation decisions. Among vertebrates, turtles represent an exceptional case for exploring these issues because of the propensity for even distantly related lineages to hybridize. In this study we investigate a group of freshwater turtles (Trachemys) from a part of its range (the Greater Antilles) where it is purported to have undergone reticulation events from both natural and anthropogenic processes. We sequenced mtDNA for 83 samples, sequenced three nuDNA markers for 45 samples, and cloned 29 polymorphic sequences, to identify species boundaries, hybridization, and intergrade zones for Antillean Trachemys and nearby mainland populations. Initial coalescent analyses of phased nuclear alleles (using (*)BEAST) recovered a Bayesian species tree that strongly conflicted with the mtDNA phylogeny and traditional taxonomy, and appeared to be confounded by hybridization. Therefore, we undertook exploratory phylogenetic analyses of mismatched alleles from the "coestimated" gene trees (Heled and Drummond, 2010) in order to identify potential hybrid origins. The geography, morphology, and sampling context of most samples with potential introgressed alleles suggest hybridization over ILS. We identify contact zones between different species on Jamaica (T. decussata × T. terrapen), on Hispaniola (T. decorata × T. stejnegeri), and in Central America (T. emolli × T. venusta). We are unable to determine whether the distribution of T. decussata on Jamaica is natural or the result of prehistoric introduction by Native Americans. This uncertainty means that the conservation status of the Jamaican T. decussata populations and contact zone with T. terrapen are unresolved. Human-mediated dispersal events were more conclusively implicated for the prehistoric translocation of T. stejnegeri between Puerto Rico and Hispaniola, as well as the more recent genetic pollution of native species by an invasive pet turtle native to the USA (T. scripta elegans). Finally, we test the impact of introgressed alleles using the multispecies coalescent in a Bayesian framework and show that studies that do not phase heterozygote sequences of hybrid individuals may recover the correct species tree, but overall support for clades that include hybrid individuals may be reduced. PMID:23353072

Parham, James F; Papenfuss, Theodore J; Dijk, Peter Paul van; Wilson, Byron S; Marte, Cristian; Schettino, Lourdes Rodriguez; Brian Simison, W



Geological interpretation of combined Seabeam, Gloria and seismic data from Anegada Passage (Virgin Islands, north Caribbean)  

USGS Publications Warehouse

The Anegada Passage (sensu lato) includes several basins and ridges from Southeast of Puerto Rico to the corner of the Virgin Islands Platform. Seabeam (Seacarib I) and Gloria long-range sidescan sonar surveys were carried out in this area. These new data allow us to propose an interpretation of the Anegada Passage. Most of the features described are related to wrench faulting: (a) St Croix and Virgin Islands Basins are pull-apart basins created in a right-lateral strike-slip environment based on their rhomboidal shape and seismic data (e.g. the flower structure). These two pull-aparts are divided into two sub-basins by a curvilinear normal fault in the Virgin Islands Basin and a right-lateral strike-slip fault in the St Croix Basin. (b) Tortola Ridge and a 'dog's leg' shaped structure are inferred to be restraining bends between two right-lateral strike-slip faults. (c) We identified two ENE-WSW volcanic lineaments in the eastern area and one volcano lying between Virgin Islands and St Croix Basins. (d) As shown by the seismic activity main wrench motion occurs along the north slope of Virgin Islands Basin and through Anegada Passage. A branching of this main fault transmits the transtensional motion to St Croix Basin. A two-stage story is proposed for the creation of the basins. A first extensional event during Eocene(?)-Oligocene-lower Miocene time created Virgin Islands, St Croix Basins and the tilted blocks of St Croix Ridge. A second transtensional event from Pliocene to Recent gave the present day pattern to this area. However, the displacement along the strike-slip faults is no more than 15 km long. The proposed geodynamic model is based on the separation of the northeastern Caribbean boundary into two blocks. In the West, the indenter of Beata Ridge gives a northeastern motion to Hispaniola Block. In the East, as a result of Hispaniola Block's motion, the Puerto Rico-Virgin Islands Block could escape in an east-northeast direction. ?? 1990 Kluwer Academic Publishers.

Jany, I.; Scanlon, K. M.; Mauffret, A.



Coevolution between Hispaniolan crossbills and pine: does more time allow for greater phenotypic escalation at lower latitude?  


Crossbills (Aves: Loxia) and several conifers have coevolved in predator-prey arms races over the last 10,000 years. However, the extent to which coevolutionary arms races have contributed to the adaptive radiation of crossbills or to any other adaptive radiation is largely unknown. Here we extend our previous studies of geographically structured coevolution by considering a crossbill-conifer interaction that has persisted for a much longer time period and involves a conifer with more variable annual seed production. We examined geographic variation in the cone and seed traits of two sister species of pines, Pinus occidentalis and P. cubensis, on the islands of Hispaniola and Cuba, respectively. We also compared the Hispaniolan crossbill (Loxia megaplaga) to its sister taxa the North American white-winged crossbill (Loxia leucoptera leucoptera). The Hispaniolan crossbill is endemic to Hispaniola whereas Cuba lacks crossbills. In addition and in contrast to previous studies, the variation in selection experienced by these pines due to crossbills is not confounded by the occurrence of selection by tree squirrels (Tamiasciurus and Sciurus). As predicted if P. occidentalis has evolved defenses in response to selection exerted by crossbills, cones of P. occidentalis have scales that are 53% thicker than those of P. cubensis. Cones of P. occidentalis, but not P. cubensis, also have well-developed spines, a known defense against vertebrate seed predators. Consistent with patterns of divergence seen in crossbills coevolving locally with other conifers, the Hispaniolan crossbill has evolved a bill that is 25% deeper than the white-winged crossbill. Together with phylogenetic analyses, our results suggest that predator-prey coevolution between Hispaniolan crossbills and P. occidentalis over approximately 600,000 years has caused substantial morphological evolution in both the crossbill and pine. This also indicates that cone crop fluctuations do not prevent crossbills and conifers from coevolving. Furthermore, because the traits at the phenotypic interface of the interaction apparently remain the same over at least several hundred thousand years, divergence as a result of coevolution is greater at lower latitude where crossbill-conifer interactions have been less interrupted by Pleistocene events. PMID:17767586

Parchman, Thomas L; Benkman, Craig W; Mezquida, Eduardo T



Do Fault Intersections Play a Role in Concentrating Seismicity along the Northern Caribbean Plate Boundary? Insights from 2-D Numerical Modeling  

NASA Astrophysics Data System (ADS)

Analytical studies spanning several decades have shown that stresses concentrate at fault intersections and bends when subjected to background tectonic loading. This phenomenon has also been demonstrated in geological systems, both within intraplate (continental and oceanic) and plate boundary settings. In particular, studies of stress interactions between strike-slip faults and the relationship between these stresses and seismicity in the northern Caribbean plate boundary region have produced a better understanding of regional tectonics. In this study we use two-dimensional mechanical modeling to investigate the role of fault intersections in concentrating seismicity along a part of the northern Caribbean plate boundary. We use a numerical method called "Distinct Element Method" implemented by a commercially available code called "UDEC". Our block model comprises of the structural geometry of a part of the northern Caribbean plate boundary spanning Hispaniola and Puerto Rico, and includes the major faults. In our model we use realistic mechanical properties (bulk and shear moduli, and density for the blocks, and stiffnesses, friction, and cohesion for the faults) based on the known geology. Assuming a linear, elastic behavior, we load our model tectonically for a specified period along the direction of the regional plate motion at a rate obtained from GPS studies in the region. At the end of the tectonic loading period we observe the spatial distribution of shear stresses in the model and along the individual faults. We find that relatively high shear stresses are concentrated at the intersections of the Hispaniola and Puerto Rico trenches, Septentrional and Bruce faults, and other fault intersections northeast of Puerto Rico. These locations of relatively high shear stresses also coincide spatially with clusters of seismicity in the region. Some of these fault intersections also have been postulated to be locations of major historical earthquakes. The areas of largest shear stresses also coincide with increased seismicity of greater magnitudes. Our modeling results also predict the appropriate senses of motion along individual faults. Additional, simple three-dimensional analysis is underway to investigate a spatial correlation of the seismicity with depth. These preliminary modeling results demonstrate that fault intersections concentrate stresses when tectonically loaded and influence the spatial distribution of seismicity. Such an analysis has the potential to identify the locations of major earthquakes in the future.

Gangopadhyay, A.; Pulliam, J.



Antillipeltis, a new genus of Antillean Trogossitidae (Coleoptera: Cleroidea) with a key to the Cleroidea.  


Antillipeltis gen. nov. is described based on the following six new extant species and two new fossil species from Hispaniola and Puerto Rico: A. alleni sp. nov. (Dominican Republic, Miocene), A. darlingtoni sp. nov. (Haiti), A. iviei sp. nov. (Dominican Republic, Miocene), A. maculata sp. nov. (Dominican Republic), A. minuta sp. nov. (Dominican Republic), A. nitida sp. nov. (Puerto Rico), A. portoricensis sp. nov. (Puerto Rico), and A. pubescens sp. nov. (Dominican Republic). The genus is placed in Cleroidea, as currently delimited, based on the presence of a distinctive type of aedeagus occurring primarily in this superfamily, plus a combination of features excluding it from other cucujiform superfamilies. Within Cleroidea, the genus is tenatively placed in the family Trogossitidae and subfamily Lophocaterinae, but it differs from all other Trogossitidae in the presence of ventral membranous lobes with adhesive setae on tarsomeres 1-4 and in a combination of 9-segmented antennae, weak 3-segmented antennal club consisting of slightly elongate antenomeres, lack of postcoxal processes on the pronotal hypomera, and unique leg modifications. A key is provided for major groups of Cleroidea and all described genera of Peltinae and Lophocaterinae, with the exception of Rentoniini, based in part on the literature and in part on dissections of adult males. Antillipeltis is one of three endemic West Indian genera of Coleoptera that is both extant and known from Dominican amber. PMID:24870333

Lawrence, John F; Leschen, Richard A B; Slipi?ski, Adam



Rio Soliette (haiti): AN International Initiative for Flood-Hazard Assessment and Mitigation  

NASA Astrophysics Data System (ADS)

Natural catastrophic events are one of most critical aspects for health and economy all around the world. However, the impact in a poor region can impact more dramatically than in others countries. Isla Hispaniola (Haiti and the Dominican Republic), one of the poorest regions of the planet, has repeatedly been hit by catastrophic natural disasters that caused incalculable human and economic losses. After the catastrophic flood event occurred in the basin of River Soliette on May 24th, 2004, the General Direction for Development and Cooperation of the Italian Department of Foreign Affairs funded an international cooperation initiative (ICI) coordinated by the University of Bologna, that involved Haitian and Dominican institutions.Main purpose of the ICI was hydrological and hydraulic analysis of the May 2004 flood event aimed at formulating a suitable and affordable flood risk mitigation plan, consisting of structural and non-structural measures. In this contest, a topographic survey was necessary to realize the hydrological model and to improve the knowledge in some areas candidates to be site for mitigation measures.To overcome the difficulties arising from the narrowness of funds, surveyors and limited time available for the survey, only GPS technique have been used, both for framing aspects (using PPP approach), and for geometrical survey of the river by means of river cross-sections and detailed surveys in two areas (RTK technique). This allowed us to reconstruct both the river geometry and the DTM's of two expansion areas (useful for design hydraulic solutions for mitigate flood-hazard risk).

Gandolfi, S.; Castellarin, A.; Barbarella, M.; Brath, A.; Domeneghetti, A.; Brandimarte, L.; Di Baldassarre, G.



The 12 Jan 2010, Haiti earthquake affected by aseismic fault creep  

NASA Astrophysics Data System (ADS)

On January 12 2010, a destructive strike-slip earthquake (Mw 7.1) occurred in the oblique convergence zone of Hispaniola. Over 222,000 people were killed, most in the capital city of Port-au-Prince in Haiti, which lies about 80 km east of the mainshock. The earthquake ruptured a 50-km fault trace along (or sub-parallel to) the much larger Enriquillo Fault Zone (EFZ) that last broke in 1751 along a ~150-km zone. Assuming an average slip rate of 5-9 mm/yr, the amount of slip deficit accumulated on the entire EFZ is estimated to be on the order of 1.5 - 2.5 meters. Here, we present results of a deformation field investigation using ScanSAR data over the period from 2004-2009, prior to the 2010 earthquake. Both the data and the models reveal that the fault segment of EFZ to the west of the 2010 earthquake has been aseismically slipping for years, at a rate similar to the interseismic long-term interseismic slip rate of EFZ. Therefore, this study shows that the accumulating stress was partly released by aseismic slip. Moreover, Coulomb stress calculations suggest that the creep at EFZ segment may have enhanced the occurrence of the 2010 earthquake disaster. The relation observed between EFZ aseismic slip and the 2010 earthquake confirmed the importance of aseismic slip to better understanding of earthquake processes and for seismic hazard mitigation.

Shirzaei, M.; Walter, T. R.



Rain from Tropical Storm Noel  

NASA Technical Reports Server (NTRS)

Though not the most powerful storm of the 2007 Atlantic Hurricane season, Tropical Storm Noel was among the most deadly. Only Category 5 Hurricane Felix and its associated flooding had a higher toll. The slow-moving Tropical Storm Noel inundated the Dominican Republic, Haiti, Jamaica, Cuba, and the Bahamas with heavy rain between October 28 and November 1, 2007. The resulting floods and mudslides left at least 115 dead and thousands homeless throughout the Caribbean, reported the Associated Press on November 2, 2007. This image shows the distribution of the rainfall that made Noel a deadly storm. The image shows rainfall totals as measured by the Multi-satellite Precipitation Analysis (MPA) at NASA Goddard Space Flight Center from October 26 through November 1, 2007. The analysis is based on measurements taken by the Tropical Rainfall Measuring Mission (TRMM) satellite. The heaviest rainfall fell in the Dominican Republic and the Bahamas, northeast of Noel's center. Areas of dark red show that rainfall totals over the south-central Dominican Republic and parts of the Bahamas were over 551 millimeters (21 inches). Much of eastern Hispaniola, including both the Dominican Republic and Haiti received at least 200 mm (about 8 inches) of rain, shown in yellow. Rainfall totals over Haiti and Cuba were less, with a range of at least 50 mm (2 inches) to over 200 mm (8 inches).



Genomic and phenotypic characterization of Vibrio cholerae non-O1 isolates from a US Gulf Coast cholera outbreak.  


Between November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally. PMID:24699521

Haley, Bradd J; Choi, Seon Young; Grim, Christopher J; Onifade, Tiffiani J; Cinar, Hediye N; Tall, Ben D; Taviani, Elisa; Hasan, Nur A; Abdullah, Abdulshakur H; Carter, Laurenda; Sahu, Surasri N; Kothary, Mahendra H; Chen, Arlene; Baker, Ron; Hutchinson, Richard; Blackmore, Carina; Cebula, Thomas A; Huq, Anwar; Colwell, Rita R



In the Aftermath of Haiti's Earthquake: A Discussion of Lessons Learned  

NASA Astrophysics Data System (ADS)

The 12 January 2010 earthquake in Haiti brought massive devastation to that country (see Figure 1). In this week's issue of Eos, three noted seismologists respond to questions from Eos senior writer Randy Showstack in a news roundtable format. Paul Mann, senior research scientist with the Institute for Geophysics at the University of Texas at Austin, has just returned from Haiti, where he and a colleague worked on a fault rupture survey; they plan to conduct an offshore fault survey soon. Glen Mattioli, professor of geosciences at the University of Arkansas, Fayetteville, has been part of a team conducting a Global Positioning System (GPS) survey of Haiti to measure ground deformation following the earthquake and to install a number of continuous GPS sites to examine after slip, viscoelastic relaxation, and the time return to interseismic deformation (see Figure 2). Work by Mann, Mattioli, and their colleagues has been supported through a U.S. National Science Foundation Rapid Response Research (RAPID) proposal grant provided to Purdue University, with Eric Calais serving as principal investigator. Carol Prentice, a seismologist with the U.S. Geological Survey's Earthquake Hazards Team, has been conducting paleoseismic research on the active faults in the Caribbean region since 1991, including projects on Hispaniola, Puerto Rico, Trinidad, and Jamaica.

Showstack, Randy



Studies in neotropical paleobotany. XIV. A palynoflora from the middle Eocene Saramaguacan formation of Cuba  

USGS Publications Warehouse

An assemblage of 46 fossil pollen and spore types is described from a core drilled through the middle Eocene Saramaguacan Formation, Camaguey Province, eastern Cuba. Many of the specimens represent unidentified or extinct taxa but several can be identified to family (Palmae, Bombacaceae, Gramineae, Moraceae, Myrtaceae) and some to genus (Pteris, Crudia, Lymingtonia?). The paleo-climate was warm-temperate to subtropical which is consistent with other floras in the region of comparable age and with the global paleotemperature curve. Older plate tectonic models show a variety of locations for proto-Cuba during Late Cretaceous and later times, including along the norther coast of South America. More recent models depict western and central Cuba as two separate parts until the Eocene, and eastern Cuba (joined to northern Hispaniola) docking to central Cuba also in the Eocene. All fragments are part of the North American Plate and none were directly connected with northern South America in late Mesozoic or Cenozoic time. The Saramaguacan flora supports this model because the assemblage is distinctly North American in affinities, with only one type (Retimonocolpites type 1) found elsewhere only in South America.

Graham, A.; Cozadd, D.; Areces-Mallea, A.; Frederiksen, N. O.



First skull of Antillothrix bernensis, an extinct relict monkey from the Dominican Republic  

PubMed Central

The nearly pristine remains of Antillothrix bernensis, a capuchin-sized (Cebus) extinct platyrrhine from the Dominican Republic, have been found submerged in an underwater cave. This represents the first specimen of an extinct Caribbean primate with diagnostic craniodental and skeletal parts in association, only the second example of a skull from the region, and one of the most complete specimens of a fossil platyrrhine cranium yet discovered. Cranially, it closely resembles living cebines but is more conservative. Dentally, it is less bunodont and more primitive than Cebus, with crowns resembling Saimiri (squirrel monkeys) and one of the oldest definitive cebines, the late Early Miocene Killikaike blakei from Argentina. The tricuspid second molar also resembles the enigmatic marmosets and tamarins, whose origins continue to present a major gap in knowledge of primate evolution. While the femur is oddly short and stout, the ulna, though more robust, compares well with Cebus. As a member of the cebid clade, Antillothrix demonstrates that insular Caribbean monkeys are not monophyletically related and may not be the product of a single colonizing event. Antillothrix bernensis is an intriguing mosaic whose primitive characters are consistent with an early origin, possibly antedating the assembly of the modern primate fauna in greater Amazonia during the La Venta horizon. While most Greater Antillean primate specimens are quite young geologically, this vanished radiation, known from Cuba (Paralouatta) and Jamaica (Xenothrix) as well as Hispaniola, appears to be composed of long-lived lineages like several other mainland clades.

Rosenberger, Alfred L.; Cooke, Siobhan B.; Rimoli, Renato; Ni, Xijun; Cardoso, Luis



Tectonic events recorded in the sediments and crust of the Caribbean sea floor  

SciTech Connect

A reconnaissance review of reflection-seismic sections from the Caribbean, together with limited information derived from dredged rocks, sediment cores, and drillholes, yields or contributes to first-order conclusions regarding the tectonic history of the water-covered Caribbean. Broadly speaking, tectonic episodes for which there is some evidence are: (1) late Cenozoic convergence and accretion along deformed continental or island margins off Panama, Colombia/Venezuela, and Hispaniola/Puerto Rico; (2) late Cenozoic generation of oceanic crust within the Cayman Trough; (3) late Cenozoic secondary deformation along the Caribbean-North American plate boundary zone, in the form of small pull-apart basins, transcurrent faults, tensional rift basins, and compressional features; (4) late Cenozoic slow disintegration of the western part of the Caribbean plate; (5) Cenozoic rift-basin formation on the upper Nicaraguan rise; (6) early Cenozoic or late Cretaceous opening of the Yucatan Basin; (7) late Cretaceous through early Cenozoic island arc formation; and (8) late Cretaceous and earlier emplacement of flow basalts in the northwestern Venezuelan Basin and possibly beneath large areas of the Caribbean. There is no evidence that except along their active margins, the Venezuelan Basin, Beata Ridge, Colombian Basin, and Nicaraguan rise areas have been sites for large-scale relative movements which created or destroyed plate material since late Cretaceous time - or earlier.

Holcombe, T.L.



Plate interaction in the NE Caribbean subduction zone from continuous GPS observations  

USGS Publications Warehouse

Kinematic similarities between the Sumatra and Puerto Rico Trenches highlight the potential for a mega-earthquake along the Puerto Rico Trench and the generation of local and trans-Atlantic tsunamis. We used the horizontal components of continuous GPS (cGPS) measurements from 10 sites on NE Caribbean islands to evaluate strain accumulation along the North American (NA) - Caribbean (CA) plate boundary. These sites move westward and slightly northward relative to CA interior at rates ?2.5 mm/y. Provided this motion originates in the subduction interface, the northward motion suggests little or no trench-perpendicular thrust accumulation and may in fact indicate divergence north of Puerto Rico, where abnormal subsidence, bathymetry, and gravity are observed. The Puerto Rico Trench, thus, appears unable to generate mega-earthquakes, but damaging smaller earthquakes cannot be discounted. The westward motion, characterized by decreasing rate with distance from the trench, is probably due to eastward motion of CA plate impeded at the plate boundary by the Bahamas platform. Two additional cGPS sites in Mona Passage and SW Puerto Rico move to the SW similar to Hispaniola and unlike the other 10 sites. That motion relative to the rest of Puerto Rico may have given rise to seismicity and normal faults in Mona Rift, Mona Passage, and SW Puerto Rico.

ten Brink, Uri S.; Lopez-Vegas, Alberto M.



Brunfelsia (Solanaceae): a genus evenly divided between South America and radiations on Cuba and other Antillean islands.  


Hallucinogenic or toxic species of Brunfelsia (Solanaceae: Petunieae) are important in native cultures throughout South America, and the genus also contains several horticulturally important species. An earlier morphological revision of the c. 50 species recognized three main groups, one consisting of the 23 Antillean species, another of southern South American and Andean species, and a third of species from the Amazon Basin and Guiana Shield. Based on plastid and nuclear DNA sequences from up to 65 accessions representing 80% of the species, we generated a phylogeny and a calibrated chronogram for Brunfelsia to infer clade expansion and shifts in pollinators and fruit types. Brunfelsia flowers offer nectar, and attract lepidoptera, hummingbirds, or bees; the fruits are dry or fleshy. Our results imply that Brunfelsia is 16-21 Myr old and entered the Antilles from South America early during its history, with subsequent expansion along the island arc. The ancestor of the Antillean clade was hawk-moth-pollinated and had fleshy capsules, perhaps facilitating dispersal by birds. The only shift to hummingbird pollination occurred on Cuba, which also harbors the largest single radiation, with 11 species (10 included in our study) that apparently arose over the past 4 Myr. Jamaica, Hispaniola, and Puerto Rico each sustained smaller radiations. The data also reveal at least one new species. PMID:22425729

Filipowicz, Natalia; Renner, Susanne S



Global survey of frequency dependent attenuation  

NASA Astrophysics Data System (ADS)

We analyze frequency-dependent attenuation of Lg waves, 1/Q(f), for numerous tectonic environments. Tectonic environments studied include: south Pacific oceanic subduction zone near Samoa, the oblique subduction zone off Hispaniola, two continental-oceanic subduction zones in Chile and Alaska, the continental-continental collision zone of the Tibetan Plateau, stable continental interior regions of the central US and Colorado Plateau, the eastern US passive margin and the active margins of the western US. Lg propagates with a group velocity of about 3.5 km/s, the average crustal shear wave velocity. This wave is commonly observed as the dominant phase on high-frequency seismograms at regional distances and is generated by a superposition of higher-mode surface waves or multiply-reflected shear energy in a crustal waveguide. Consequently, Lg provides a good measure of path-averaged crustal properties, such as shear-wave velocity and attenuation. Lg is particularly useful since its amplitude is sensitive to lateral heterogeneity in the crust due to varying tectonic environment. In this global survey we observe that Lg attenuation is generally higher for tectonically active regions than for stable continental interiors. Q(f) is an important physical parameter and is required for a variety of USGS research projects such as the simulation of strong ground motion and seismic network magnitude detection threshold modeling.

McNamara, D. E.; Benz, H.; Gee, L. S.; Frankel, A. D.



Evidence for higher tropical storm risks in Haiti due to increasing population density in hazard prone urban areas  

NASA Astrophysics Data System (ADS)

Since the 18th century, the Republic of Haiti has experienced numerous tropical cyclones. In 2011, the United Nations Global Assessment Report on Disaster Risk Reduction outlined that the worldwide physical exposure to natural hazards, which includes tropical storms and hurricanes in Haiti, increased by 192 per cent between 1970 and 2010. Now, it can be hypothesized that the increased physical exposure to cyclones that made landfall in Haiti has affected the country's development path. This study shows that tropical storm risks in Haiti increased due to more physical exposure of the population in urban areas rather than a higher cyclone frequency in the proximity of Hispaniola island. In fact, the population density accelerated since the second half of the 20th century in regions where historically more storms made landfall, such as in the departments Ouest, Artibonite, Nord and Nord-Ouest including Haiti's four largest cities: Port-au-Prince, Gonaïves, Cap-Haïtien and Port-de-Paix. Thus, urbanization in and migration into storm hazard prone areas could be considered as one of the major driving forces of Haiti's fragility.

Klose, Christian D.



Genomic and Phenotypic Characterization of Vibrio cholerae Non-O1 Isolates from a US Gulf Coast Cholera Outbreak  

PubMed Central

Between November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally.

Grim, Christopher J.; Onifade, Tiffiani J.; Cinar, Hediye N.; Tall, Ben D.; Taviani, Elisa; Hasan, Nur A.; Abdullah, AbdulShakur H.; Carter, Laurenda; Sahu, Surasri N.; Kothary, Mahendra H.; Chen, Arlene; Baker, Ron; Hutchinson, Richard; Blackmore, Carina; Cebula, Thomas A.; Huq, Anwar; Colwell, Rita R.



Distributed Active Folding across the Northern Caribbean Plate Boundary Derived from the Combined Analysis of Srtm Topography and Seismic Profiling  

NASA Astrophysics Data System (ADS)

Sinistral transpression across the northern Caribbean plate boundary is partitioned across Hispaniola between two subparallel transforms that accommodate strike-slip motion, and a wide swath of intervening NW-trending folds. These folds correspond to mountain chains continuous with offshore anticlinal ridges. The mapping of onshore flights of marine terraces exposed across these folds, combined with the dating of fossil corals, have constrained uplift rates for their emerged portions [Mann et al., 1995]. Slope maps produced from recently released SRTM (Shuttle Radar Topography Mission) data with a resolution of ~30 m highlight the full 3D geometry of the deformed marine terraces across these folds. Offshore multichannel seismic reflection (MCS) profiles collected in 1982 by GSI / Western Geophysical constrain the broader geometry of the submerged anticline limbs. This combined dataset is used to investigate the deformation history of four folds whose emerged limbs are only moderately disrupted by mass wasting. One of the exposed structures (St Marc peninsula) displays both fold limbs, with the highest uplift predictably centered on the axial trace of the fold. Two others display terraces that remain planar and are progressively tilted away from the presumed anticline crests, indicating in each case that only one of the fold limbs is exposed above sea level and that it is subsiding relative to the crest. Lastly, the west end of Gonave Island, the WNW-trending island located between the north and south peninsulas of Haiti, displays nearly horizontal terraces. While prior investigation of the lowest ~125 ka terrace indicates that it has not uplifted since it was formed [Mann et al., 1995], nearshore MCS data reveal a ~350 m-deep horizontal erosional surface that truncates folded reflectors. This suggests that the submerged portion of the Gonave anticline crest is subsiding. Furthermore, progressive tilting of the seismic reflectors on the fold limbs requires that these limbs are subsiding relative to the crest. Major extension, inferred to be Eocene, is seismically imaged north of Gonave Island, with the post-extension angular unconformity now lying at up to several km depth. The extended, thinned crust is expected to have subsided, a process augmented by post-extension sedimentation. Therefore, a lack of subsidence for the ~125 ka terrace on Gonave Island likely requires some growth of structural relief. We propose that such structural growth is driven by slip on an imaged blind NNE-dipping thrust fault beneath Gonave Island. These results will be used to evaluate whether significant amount of contraction has been recently accommodated across the thrust folds, and what process may be causing subsidence despite folding and, presumable, crustal thickening. The distribution and partitioning of strain on and near western Hispaniola are critical information for evaluating the seismic hazards facing Haiti.

Cormier, M.; Seeber, L.; Sorlien, C. C.; Steckler, M. S.; Gulick, S. P.; McHugh, C. M.; Hornbach, M.



"Darwin's butterflies"? DNA barcoding and the radiation of the endemic Caribbean butterfly genus Calisto (Lepidoptera, Nymphalidae, Satyrinae)  

PubMed Central

Abstract The genus Calisto Hübner, 1823 is the only member of the diverse, global subfamily Satyrinae found in the West Indies, and by far the richest endemic Caribbean butterfly radiation. Calisto species occupy an extremely diverse array of habitats, suggestive of adaptive radiation on the scale of other classic examples such as the Galápagos or Darwin’s finches. However, a reliable species classification is a key requisite before further evolutionary or ecological research. An analysis of 111 DNA ‘barcodes’ (655 bp of the mitochondrial gene COI) from 29 putative Calisto species represented by 31 putative taxa was therefore conducted to elucidate taxonomic relationships among these often highly cryptic and confusing taxa. The sympatric, morphologically and ecologically similar taxa Calisto confusa Lathy, 1899 and Calisto confusa debarriera Clench, 1943 proved to be extremely divergent, and we therefore recognize Calisto debarriera stat. n. as a distinct species, with Calisto neiba Schwartz & Gali, 1984 as a junior synonym syn. n. Species status of certain allopatric, morphologically similar sister species has been confirmed: Calisto hysius (Godart, 1824) (including its subspecies Calisto hysius aleucosticha Correa et Schwartz, 1986, stat. n.), and its former subspecies Calisto batesi Michener, 1943 showed a high degree of divergence (above 6%) and should be considered separate species. Calisto lyceius Bates, 1935/Calisto crypta Gali, 1985/Calisto franciscoi Gali, 1985 complex, also showed a high degree of divergence (above 6%), confirming the species status of these taxa. In contrast, our data suggest that the Calisto grannus Bates, 1939 species complex (including Calisto grannus dilemma González, 1987, Calisto grannus amazona González, 1987, stat. n., Calisto grannus micrommata Schwartz & Gali, 1984, stat. n., Calisto grannus dystacta González, 1987, stat. n., Calisto grannus phoinix González, 1987, stat. n., Calisto grannus sommeri Schwartz & Gali, 1984, stat. n., and Calisto grannus micheneri Clench, 1944, stat. n.) should be treated as a single polytypic species, as genetic divergence among sampled populations representing these taxa is low (and stable morphological apomorphies are absent). A widely-distributed pest of sugar cane, Calisto pulchella Lathy, 1899 showed higher diversification among isolated populations (3.5%) than expected, hence supporting former separation of this species into two taxa (pulchella and darlingtoni Clench, 1943), of which the latter might prove to be a separate species rather than subspecies. The taxonomic revisions presented here result in Calisto now containing 34 species and 17 subspecies. Three species endemic to islands other than Hispaniola appear to be derived lineages of various Hispaniolan clades, indicating ancient dispersal events from Hispaniola to Puerto Rico, Cuba, and Jamaica. Overall, the degree of intrageneric and intraspecific divergence within Calisto suggests a long and continuous diversification period of 4–8 Myr. The maximum divergence within the genus (ca. 13.3%) is almost equivalent to the maximum divergence of Calisto from the distant pronophiline relative Auca Hayward, 1953 from the southern Andes (14.1%) and from the presumed closest relative Eretris Thieme, 1905 (14.4%), suggesting that the genus began to diversify soon after its split from its continental sister taxon. In general, this ‘barcode’ divergence corresponds to the high degree of morphological and ecological variation found among major lineages within the genus.

Sourakov, Andrei; Zakharov, Evgeny V.



Faith based aviation: An ethnographic study of missionary flights international  

NASA Astrophysics Data System (ADS)

The development of faith-based missionary aviation is a post-World War II phenomenon. The war effort demonstrated the value, utility, and global reach of aviation to remote, underdeveloped areas of the world. With the beginnings of a worldwide infrastructure for aviation, Christian aviators realized aviation could increase the range and effectiveness of their efforts to reach the world for Christ (Mellis, 2006). Although individual organizations provide statistical information and data about flight operations there is a lack of external evidence and relevant research literature confirming the scope and value of these faith based aviation organizations and operations. A qualitative, ethnographic study was conducted to document the activities of one faith-based aviation organization to gain an understanding of this little known aspect of civilian aviation. The study was conducted with Missionary Flights International (MFI) of Fort Pierce, FL which has been involved in faith-based, missionary aviation since its inception in 1964. As an aviation organization "MFI strives to offer affiliated missions the kind of efficient service and professionalism expected of an airline operation" (Missionary Flights International, 2013, p.1). MFI is a lifeline for missionaries to Haiti and the Dominican Republic, fulfilling their motto of "Standing in the Gap". MFI provides twice a week service to the island of Hispaniola and the Republic of Haiti. In this in-depth study insight and understanding was gained into the purpose of MFI, their daily routines and operations, and the challenges they face in maintaining their flight services to Haiti. This study provided documentation of the value and utility of such aviation efforts and of the individuals involved in this endeavor.

Cooper, Joseph H.


Benefits of studies of overwintering birds for understanding resident bird ecology and promoting development of conservation capacity.  


Funding of ecological research and monitoring of Neotropical migratory birds on their overwintering grounds has benefited both migratory and permanent-resident species. Using examples from our work in Puerto Rico and the Dominican Republic, we demonstrate that ecological research of overwintering migrants often provides information about the ecology and demography of little-known tropical resident birds. Critically important long-term monitoring in Puerto Rico with a focus on winter residents has provided information on the relationships between annual rainfall and fluctuations in resident bird populations and survival rates. It also has alerted local biologists to declines in resident bird populations, including a decline apparently driven by the entry of a brood parasite. But migrant-focused research may also have had an underappreciated effect on the development of conservation capacity and conservation efforts in host countries. Investments in research on Neotropical migrants overwintering on Hispaniola have resulted in a huge increase in field training of students and wildlife professionals, promoted conservation awareness at local and national levels, played an important role in the growth and professionalization of key environmental organizations, spawned a growing ecotourism industry for bird-watching, and driven national park management planning and conservation efforts for all bird species. We encourage funding organizations and agencies to consider the broader impacts of funding migratory-bird research and monitoring efforts, and we encourage researchers in the tropics to use protocols that provide the most information about all the birds that use the study areas involved and to be aware of important opportunities that they may have to build capacity in host countries. PMID:19016823

Latta, Steven C; Faaborg, John



Reconstructing the population genetic history of the Caribbean.  


The Caribbean basin is home to some of the most complex interactions in recent history among previously diverged human populations. Here, we investigate the population genetic history of this region by characterizing patterns of genome-wide variation among 330 individuals from three of the Greater Antilles (Cuba, Puerto Rico, Hispaniola), two mainland (Honduras, Colombia), and three Native South American (Yukpa, Bari, and Warao) populations. We combine these data with a unique database of genomic variation in over 3,000 individuals from diverse European, African, and Native American populations. We use local ancestry inference and tract length distributions to test different demographic scenarios for the pre- and post-colonial history of the region. We develop a novel ancestry-specific PCA (ASPCA) method to reconstruct the sub-continental origin of Native American, European, and African haplotypes from admixed genomes. We find that the most likely source of the indigenous ancestry in Caribbean islanders is a Native South American component shared among inland Amazonian tribes, Central America, and the Yucatan peninsula, suggesting extensive gene flow across the Caribbean in pre-Columbian times. We find evidence of two pulses of African migration. The first pulse--which today is reflected by shorter, older ancestry tracts--consists of a genetic component more similar to coastal West African regions involved in early stages of the trans-Atlantic slave trade. The second pulse--reflected by longer, younger tracts--is more similar to present-day West-Central African populations, supporting historical records of later transatlantic deportation. Surprisingly, we also identify a Latino-specific European component that has significantly diverged from its parental Iberian source populations, presumably as a result of small European founder population size. We demonstrate that the ancestral components in admixed genomes can be traced back to distinct sub-continental source populations with far greater resolution than previously thought, even when limited pre-Columbian Caribbean haplotypes have survived. PMID:24244192

Moreno-Estrada, Andrés; Gravel, Simon; Zakharia, Fouad; McCauley, Jacob L; Byrnes, Jake K; Gignoux, Christopher R; Ortiz-Tello, Patricia A; Martínez, Ricardo J; Hedges, Dale J; Morris, Richard W; Eng, Celeste; Sandoval, Karla; Acevedo-Acevedo, Suehelay; Norman, Paul J; Layrisse, Zulay; Parham, Peter; Martínez-Cruzado, Juan Carlos; Burchard, Esteban González; Cuccaro, Michael L; Martin, Eden R; Bustamante, Carlos D



Mélanges and olistostromes in the Puerto Plata area (northern Dominican Republic) as a record of subduction and collisional processes between the Caribbean and North-American plates  

NASA Astrophysics Data System (ADS)

The Cordillera Septentrional records the oblique subduction and collisional processes between the Caribbean and North American plates during Late Cretaceous to early Palaeogene times. The Puerto Plata basement complex of this range is considered to represent a fragment of the frontal part of the Great Arc of the Caribbean in Hispaniola that originated during thrusting of the Caribbean plate onto the North American shelf. This paper describes and interprets mélange-type formations spatially related to this basement complex and its associated sedimentary cover, the Imbert Fm. Such formations include the San Marcos olistostromic Fm and a unit of Serpentinic Breccias located at the base and interbedded in the lower section of the former. Both units are Eocene in age, have been mainly deposited by syntectonic subaqueous mass-transport processes and typically host a varied mixture of blocks of known and unknown origin, including high-P metamorphic rocks (knockers). Cartoon models of palaeotectonic reconstructions depicting the final stages of subduction and the onset of collisional process in Early and Middle Eocene times respectively, are proposed in order to show the original relationships among all geological units involved in the study area. The Serpentinic Breccias are interpreted as being the result of extensive sedimentary recycling of peridotite and serpentinite massive bodies or subduction related mélanges when exposed at the surface by return flow during early exhumation stages of the accretionary complex, coevally with the end of island-arc volcanism. This process is inferred to be the triggering mechanism for the feeding of originally deep-sited knockers, probably in combination with strike-slip tectonics and associated mud diapirism The slightly younger San Marcos Fm records the collision event and main exhumation stage, while displaying the typical features present in olistostromes and other mass-wasting, gravitationally-driven deposits recognized in extensive areas of forearc and accretionary complexes involved in arc-continent collisional processes.

Hernaiz Huerta, P. P.; Pérez-Valera, F.; Abad, M.; Monthel, J.; Diaz de Neira, A.



From transtension to transpression along the northern Caribbean plate boundary off Cuba: implications for the Recent motion of the Caribbean plate  

NASA Astrophysics Data System (ADS)

Marine geophysical surveys using Seabeam, single-channel seismic reflection, gravimetric and magnetic measurements have been conducted along a segment of the northern Caribbean transcurrent plate boundary (SEACARIB II cruise). The data allow a better definition of the geometry and the tectonic regime of this major strike-slip area. They support the following results: (1) Along the southern Cuban margin, the Oriente fault displays a discontinuous trace, mainly composed of dextral offset, "en echelon" segments. Some pull-apart basins are located between fault segments (Cabo Cruz basin, Chivirico and Baitiquiri basins). In the Windward Passage area, the plate boundary enters into the Tortue Channel and is not connected with the subduction front off northern Hispaniola. (2) The eastern part of the Oriente Deep and the Santiago Promontory are characterised by active compressional tectonics. They form the Santiago Deformed Belt, described here for the first time. This deformed belt can be divided longitudinally into three main segments, each one characterised by a particular tectonic style. Its development is related to a transpressional mechanism along the left-lateral Oriente strike-slip fault. Our observations suggest that a tectonic and kinematic reorganisation occurred recently in this area, probably in the Late Pliocene, which may be compared with the recent geological events recorded on land in the northern Caribbean domain. The precise knowledge of both geometry and structures along the Oriente strike-slip fault south of Cuba provides new constraints for the recent kinematic evolution along the northern Caribbean transcurrent plate boundary: it leads us to infer the existence of a convergence component associated with the slip component along the Oriente transform fault.

Calais, Eric; de Lepinay, Bernard Mercier



Tsunami hazard in the Caribbean: Regional exposure derived from credible worst case scenarios  

NASA Astrophysics Data System (ADS)

The present study documents a high tsunami hazard in the Caribbean region, with several thousands of lives lost in tsunamis and associated earthquakes since the XIXth century. Since then, the coastal population of the Caribbean and the Central West Atlantic region has grown significantly and is still growing. Understanding this hazard is therefore essential for the development of efficient mitigation measures. To this end, we report a regional tsunami exposure assessment based on potential and credible seismic and non-seismic tsunamigenic sources. Regional tsunami databases have been compiled and reviewed, and on this basis five main scenarios have been selected to estimate the exposure. The scenarios comprise two Mw8 earthquake tsunamis (north of Hispaniola and east of Lesser Antilles), two subaerial/submarine volcano flank collapse tsunamis (Montserrat and Saint Lucia), and one tsunami resulting from a landslide on the flanks of the Kick'em Jenny submarine volcano (north of Grenada). Offshore tsunami water surface elevations as well as maximum water level distributions along the shore lines are computed and discussed for each of the scenarios. The number of exposed people has been estimated in each case, together with a summary of the tsunami exposure for the earthquake and the landslide tsunami scenarios. For the earthquake scenarios, the highest tsunami exposure relative to the population is found for Guadeloupe (6.5%) and Antigua (7.5%), while Saint Lucia (4.5%) and Antigua (5%) have been found to have the highest tsunami exposure relative to the population for the landslide scenarios. Such high exposure levels clearly warrant more attention on dedicated mitigation measures in the Caribbean region.

Harbitz, C. B.; Glimsdal, S.; Bazin, S.; Zamora, N.; Løvholt, F.; Bungum, H.; Smebye, H.; Gauer, P.; Kjekstad, O.



Bivergent thrust wedges surrounding oceanic island arcs: Insight from observations and sandbox models of the northeastern caribbean plate  

USGS Publications Warehouse

At several localities around the world, thrust belts have developed on both sides of oceanic island arcs (e.g., Java-Timor, Panama, Vanuatu, and the northeastern Caribbean). In these localities, the overall vergence of the backarc thrust belt is opposite to that of the forearc thrust belt. For example, in the northeastern Caribbean, a north-verging accretionary prism lies to the north of the Eastern Greater Antilles arc (Hispaniola and Puerto Rico), whereas a south-verging thrust belt called the Muertos thrust belt lies to the south. Researchers have attributed such bivergent geometry to several processes, including: reversal of subduction polarity; subduction-driven mantle flow; stress transmission across the arc; gravitational spreading of the arc; and magmatic inflation within the arc. New observations of deformational features in the Muertos thrust belt and of fault geometries produced in sandbox kinematic models, along with examination of published studies of island arcs, lead to the conclusion that the bivergence of thrusting in island arcs can develop without reversal of subduction polarity, without subarc mantle flow, and without magmatic inflation. We suggest that the Eastern Greater Antilles arc and comparable arcs are simply crustalscale bivergent (or "doubly vergent") thrust wedges formed during unidirectional subduction. Sandbox kinematic modeling suggests, in addition, that a broad retrowedge containing an imbricate fan of thrusts develops only where the arc behaves relatively rigidly. In such cases, the arc acts as a backstop that transmits compressive stress into the backarc region. Further, modeling shows that when arcs behave as rigid blocks, the strike-slip component of oblique convergence is accommodated entirely within the prowedge and the arc-the retrowedge hosts only dip-slip faulting ("frontal thrusting"). The existence of large retrowedges and the distribution of faulting in an island arc may, therefore, be evidence that the arc is relatively rigid. The rigidity of an island arc may arise from its mafi c composition and has implications for seismic-hazard analysis. ?? 2009 Geological Society of America.

ten, Brink, U. S.; Marshak, S.; Granja, Bruna, J. -L.



Large-Scale Introgression Shapes the Evolution of the Mating-Type Chromosomes of the Filamentous Ascomycete Neurospora tetrasperma  

PubMed Central

The significance of introgression as an evolutionary force shaping natural populations is well established, especially in animal and plant systems. However, the abundance and size of introgression tracts, and to what degree interspecific gene flow is the result of adaptive processes, are largely unknown. In this study, we present medium coverage genomic data from species of the filamentous ascomycete Neurospora, and we use comparative genomics to investigate the introgression landscape at the genomic level in this model genus. We revealed one large introgression tract in each of the three investigated phylogenetic lineages of Neurospora tetrasperma (sizes of 5.6 Mbp, 5.2 Mbp, and 4.1 Mbp, respectively). The tract is located on the chromosome containing the locus conferring sexual identity, the mating-type (mat) chromosome. The region of introgression is confined to the region of suppressed recombination and is found on one of the two mat chromosomes (mat a). We used Bayesian concordance analyses to exclude incomplete lineage sorting as the cause for the observed pattern, and multilocus genealogies from additional species of Neurospora show that the introgression likely originates from two closely related, freely recombining, heterothallic species (N. hispaniola and N. crassa/N. perkinsii). Finally, we investigated patterns of molecular evolution of the mat chromosome in Neurospora, and we show that introgression is correlated with reduced level of molecular degeneration, consistent with a shorter time of recombination suppression. The chromosome specific (mat) and allele specific (mat a) introgression reported herein comprise the largest introgression tracts reported to date from natural populations. Furthermore, our data contradicts theoretical predictions that introgression should be less likely on sex-determining chromosomes. Taken together, the data presented herein advance our general understanding of introgression as a force shaping eukaryotic genomes.

Menkis, Audrius; Whittle, Carrie A.; Andersson, Siv G. E.; Johannesson, Hanna



Vertical Deformation of Late Quaternary Features Across Port-au-Prince Bay, Haiti  

NASA Astrophysics Data System (ADS)

As part of a project that investigated the underwater impacts of the January 12, 2010 earthquake in Haiti, we surveyed offshore structures that may have been activated during that earthquake or that might become activated in future earthquakes. Part of that survey focused on the shallow shelf area that extends north of the segment of the Enriquillo-Plantain Garden fault that just ruptured. This area is occupied by an elongated depression, 25 km long, 10 km wide, and 140 m deep. The NW-SE axis of that shallow basin is sub-parallel to that of the NW-SE anticlines that bounds Port-au-Prince Bay. The shallow basin is also rimmed by a carbonate platform that is 5-10 km-wide and ~30m deep. New multibeam bathymetric and sidescan sonar data collected across that platform highlight a series of circular dissolution structures 1-2 km across and ~80 m deep. We interpret that morphology to indicate antecedent karst topography that developed during previous glacial maxima. According to that scenario, the shallow basin off Port-au-Prince would have been isolated from the Caribbean Sea by the continuous platform, and would probably have been occupied by a lagoon. Indeed, a few high-resolution chirp profiles image what may be a paleoshoreline at about 80m depth, buried beneath a 5-8 m thick, acoustically transparent, presumably Holocene layer. Preliminary analysis indicates that the basin floor and the base of the presumably Holocene layer are perfectly horizontal in the center of the basin, but tilted down to the south at its northern edge. The presumed paleoshoreline is also shallower to the north of the basin. We propose that this tilt is driven by contraction across the NW-SE fold-and-thrust belt that runs across Hispaniola. This hypothesis remains to be tested with a more thorough geophysical and coring survey in Port-au-Prince Bay.

Cormier, M.; McHugh, C. M.; Gulick, S. P.; Braudy, N.; Davis, M. B.; Diebold, J. B.; Dieudonne, N.; Douilly, R.; Hornbach, M. J.; Johnson, H. E.; Mishkin, K.; Seeber, L.; Sorlien, C. C.; Steckler, M. S.; Symithe, S. J.; Templeton, J.



Jurassic hydrocarbon exploration of southern Florida  

SciTech Connect

South Florida Jurassic exploration has been overlooked as a viable exploration target due to lack of data and plate-tectonics application. In Florida, {open_quotes}basement{close_quotes} is defined as crystalline, igneous, metamorphic, and unmetamorphosed sediments of Paleozoic age. Age-dating of zircons has proven that the Florida lower Paleozoic terrane is not akin to that of North America but is part of the West African Guinean shield. Previous published reconstructions of late Paleozoic fits of crustal plates and continents have failed to account for the differences in peninsula Florida basement and the geologic and tectonic continuities of peninsula Florida, Yucatan, Cuba, Hispaniola, and Bahamas. Pre-Atlantic reconstruction of the Gulf of Mexico in this study proposes that there was a Florida connection to Yucatan-Cuba-Africa during the Triassic. This reconstruction also shows that the Jurassic sediments that are well known in the northern Gulf Coast should have been deposited in similar depositional environments in southern Florida. Deep drilling on the Florida peninsula has confirmed this hypothesis. By using plate tectonic reconstruction based on the rising of the North Atlantic Ocean and evidence from petrology of basement samples from deep wells together with petrographic analyses of Jurassic sediments, a Smackover-equivalent exploration play can be developed. Petrographic and petrophysical analysis of these wells that have encountered Jurassic marine shales, anhydrite, dolomite, carbonate, and elastic sediments has determined that these sediments are from shallow-water subtidal, tidal, intertidal, and supratidal environments. Excellent gas shows, oil stain in the pores and high TOC values in the marine shales, indicate that large accumulations of hydrocarbon are present.

Mitchell-Tapping, H.J. [Retog, Inc., DeSoto, TX (United States)



Studies on mosquito borne dieases in Egypt and Qatar.  


Mosquitoes identification, distribution and densities in representative Egyptian Governorates and five Qatarain Municipalities (Al Rayyan, Doha, Al Daayan, Al Khor & Al Zahakira and Al Shamal) were studied. In Qatar the larvae were Culex pipiens complex, C. univettatus, C. pusillus, Aedes caspies, Anopheles multicolor and A. stephensi. C. pipiens and C. univettatus were mainly in Al Rayyan, Doha, and Al Khor & Al Zahakira. C. pusillus was in Doha and Al Daayan while A. caspies was in Al Daayan and Al Shamal. Anopheles multicolor and A. stephensi were mainly in Al Shamal with low density in Al Rayyan (only in Ain-Khalid locution). The Egyptian mosquitoes were C. pipiens, C. antennatus, C. thelerei, C. univittatus, C. perexiguus, C. poicilipes, C. pusillus, Aedes caspius, Ae. detritus, A. sergentii, A. pharoensis, A. multicolor, A. detali, A. algeriensis, A. tenebrosus, A. gambiae (formerly), A. superpictus, A. tarkhadi, A. hispaniola, A. rhodesiensis, A. stephensi, A. coustani and Culiseta longiareolata. As an example in Sharkia Governorate, larvae were C. pipiens (68.77%), Ae. caspius (15.75%), Culiseta sp. (=Theobaldia) and C. pusillus. In Greater Cairo, parts of Qualyoubia G., C. pipiens was the most dominant and the least was C. perexiguus. In parts of Giza G., C. pipiens was the most dominant and least was Cs. longiareolata. In Cairo G., C. pipiens was the most dominant and least was Ae. caspius. The overall in Greater Cairo was C. pipiens (61.74%), Cs. longiareolata (15.56%), Ae. caspius (15.3%), C. pusillus (4.0%) and C. perexiguus (3.16%). PMID:20120742

Mikhail, Micheal W; Al-Bursheed, Khalifa M; Abd El-Halim, Azza S; Morsy, Tosson A



Near-surface phytoplankton distribution in the western Intra-Americas Sea: The influence of El Niño and weather events  

NASA Astrophysics Data System (ADS)

The space-time variation of phytoplankton pigments in the western Intra-Americas Sea (IAS), in the vicinity of the island of Cuba, is examined using digital images obtained with the Coastal Zone Color Scanner sensor flown aboard the Nimbus 7 satellite from 1978 to 1986. The results are compared to historical in situ hydrographic observations. A marked seasonality in pigment concentration was observed in waters around Cuba, with an average of 0.07 mg m-3 in summer (April-September) and 0.13 mg m-3 during winter (October-March). The range of variation in pigment concentration was larger in the Gulf of Mexico relative to the western Caribbean Sea. We identified four biogeographical areas on the basis of groups of pixels with similar patterns of time variability. These are area I: southwest of Cuba, Yucatan Channel, and Florida Strait; area II: central Gulf of Mexico; area III: east of Cuba; and area IV: central Caribbean Sea, south of Jamaica and Hispaniola. Two major meteorological events led to anomalies in the seasonal cycle of pigment concentrations. During El Niño-Southern Oscillation (ENSO) of 1982-1983, positive anomalies were observed in the pigment concentration in the western IAS during winter months. This was associated with intense mixing of the water column by higher-frequency and stronger winds associated with cold fronts. ENSO 1982-1983 therefore had a fertilizing effect on the IAS region. Another positive anomaly was observed in 1980-1981, a non-ENSO period that featured higher hurricane and extratropical low-pressure activity.

González, Nelson Melo; Müler-Karger, Frank E.; Estrada, Sergio Cerdeira; de los Reyes, Roberto Pérez; del Río, Iván Victoria; Pérez, Pedro Cárdenas; Arenal, Ida Mitrani



Permo-Triassic reconstruction of western Pangea and the evolution of the Gulf of Mexico&solCaribbean region  

NASA Astrophysics Data System (ADS)

A Permo-Triassic reconstruction of western Pangea (North America, South America, Africa) is proposed that is characterized by (1) definition of the North Atlantic fit by matching of marginal offsets (fracture zones) along the opposing margins, (2) a South Atlantic fit that is tighter than the BuIlard fit and that is achieved by treating Africa as two plates astride the Benue Trough and related structures during the Cretaceous, (3) complete closure of the Proto-Atlantic Ocean between North and South America, accomplished by placing the Yucatan block between the Ouachita Mountains and Venezuela, (4) a proposed Hercynian suture zone that separates zones of foreland thrusting from zones of arc-related magmatic activity; to the northwest of this suture lie the Chortis block and Mexico and most of North America, and to the southeast lie South America, the Yucatan Block, Florida and Africa, and (5) satisfaction of paleomagmatic data from North America, South America, and Africa. Beginning with the proposed reconstruction, the relative motion history of South America with respect of North America is defined by using the finite difference method. Within the framework provided by the proposed relative motion history, an evolutionary model for the development of the Gulf of Mexico and Caribbean region is outlined in a series of 13 plate boundary reconstructions at time intervals from the Jurassic to the present. The model includes (1) formation of the Gulf of Mexico by 140 Ma, (2) Pacific provenance of the Caribbean plate through the North America-South America gap during Cretaceous time, (3) Paleocene-Early Eocene back arc spreading origin for the Yucatan Basin, whereby Cuba is the frontal arc and the Nicaragua Rise-Jamaica-Southern Hispaniola is the remnant arc, and (4) 1200 km of post-Eocene cumulative offset along both the Northern and Southern Caribbean Plate Boundary Zones, allowing large-scale eastward migration of the Caribbean plate with respect to the North and South American Plates.

Pindell, James; Dewey, John F.



Early implications of the COCONet GPS velocity field for studies of plate and microplate motions in the Caribbean  

NASA Astrophysics Data System (ADS)

Now entering their 3rd decade, GPS measurements in the Caribbean region have been used to study a wide range of tectonic topics such as the movement of the Caribbean plate relative to North and South America, earthquake cycle effects along the seismically hazardous Caribbean plate boundary faults, and microplate interactions along the complexly deforming Caribbean plate boundaries. The construction of COCONet stands out as the most significant-ever one-time advance in GPS-MET infrastructure in the Caribbean region due to its standardized GPS-MET equipment, its open access to real-time data, and its expansion of coverage relative to pre-existing GPS stations. In this talk, I will show an up-to-date Caribbean region velocity field derived using the most recent version of GIPSY software (release 6.1), the latest satellite orbit products, single-station ambiguity resolution, and a consistent realization of the Caribbean plate reference frame. Consisting of several hundred site velocities, the new velocity field clearly defines how the crust responds to east-to-west changes in the geometry of the Caribbean-North America plate boundary, including the profound effect of the oblique collision zone between the Bahama platform and northern edge of the Caribbean plate. I will discuss implications of the still-maturing COCONet GPS velocities for ongoing studies of Caribbean plate motion and plate rigidity and will also discuss applications of COCONet velocities for testing recently published kinematic estimates for the movements of the Gonave, Puerto Rico, Hispaniola, and southern Jamaica microplates.

DeMets, C.



Role of the offshore Pedro Banks left-lateral strike-slip fault zone in the plate tectonic evolution of the northern Caribbean  

NASA Astrophysics Data System (ADS)

Previous workers, mainly mapping onland active faults on Caribbean islands, defined the northern Caribbean plate boundary zone as a 200-km-wide bounded by two active and parallel strike-slip faults: the Oriente fault along the northern edge of the Cayman trough with a GPS rate of 14 mm/yr, and and the Enriquillo-Plaintain Garden fault zone (EPGFZ) with a rate of 5-7 mm/yr. In this study we use 5,000 km of industry and academic data from the Nicaraguan Rise south and southwest of the EPGFZ in the maritime areas of Jamaica, Honduras, and Colombia to define an offshore, 700-km-long, active, left-lateral strike-slip fault in what has previously been considered the stable interior of the Caribbean plate as determined from plate-wide GPS studies. The fault was named by previous workers as the Pedro Banks fault zone because a 100-km-long segment of the fault forms an escarpment along the Pedro carbonate bank of the Nicaraguan Rise. Two fault segments of the PBFZ are defined: the 400-km-long eastern segment that exhibits large negative flower structures 10-50 km in width, with faults segments rupturing the sea floor as defined by high resolution 2D seismic data, and a 300-km-long western segment that is defined by a narrow zone of anomalous seismicity first observed by previous workers. The western end of the PBFZ terminates on a Quaternary rift structure, the San Andres rift, associated with Plio-Pleistocene volcanism and thickening trends indicating initial rifting in the Late Miocene. The southern end of the San Andreas rift terminates on the western Hess fault which also exhibits active strands consistent with left-lateral, strike-slip faults. The total length of the PBFZ-San Andres rift-Southern Hess escarpment fault is 1,200 km and traverses the entire western end of the Caribbean plate. Our interpretation is similar to previous models that have proposed the "stable" western Caribbean plate is broken by this fault whose rate of displacement is less than the threshold recognizable from the current GPS network (~3 mm/yr). The Late Miocene age of the fault indicates it may have activated during the Late Miocene to recent Hispaniola-Bahamas oblique collision event.

Ott, B.; Mann, P.; Saunders, M.



Mass flow in serpentinite-hosted subduction channels: P - T - t path patterns of metamorphic blocks in the Rio San Juan mélange (Dominican Republic)  

NASA Astrophysics Data System (ADS)

Serpentinite mélanges formed in the subduction zone channel of an intra-oceanic arc system are exposed in the Rio San Juan complex of northern Hispaniola. This study presents an array of pressure-temperature paths for 14 metamorphic blocks. The P- T paths were constructed from isochemical P- T phase diagrams ("pseudosections") as well as multi-equilibrium calculations on mineral assemblages, providing for the first time the means to compare P- T paths in both time and space. The study involves metabasic, meta-andesitic and metagranitic lithologies. Subduction was slow, so that the uninterrupted thermal development of the subduction zone can be followed over a time span of more than 60 Myr. Early eclogites mirror "warm" subduction zone gradients (˜18°/km); both clockwise and anticlockwise paths are found. The maximum P- T conditions reached are ˜800 °C and 26 kbar, thus indicating sufficient buoyancy for return flow from depths exceeding the stability of serpentine. As the subduction zone matures, P/ T gradients gradually steepen to ˜6°/km, and the maximum depth from which blocks are exhumed decreases in a regular way from 26 to 17 kbar. The exhumed metamorphic products are initially omphacite-bearing blueschists and evolve to jadeite- and lawsonite-bearing blueschists with veins of jadeitite jade. Lawsonite eclogites are not found, because in the latest history of the subduction zone the predominantly basic geochemistry of the blocks evolved to more intermediate compositions inappropriate for this rock type. There are no indications of systematic differences or episodic variations in subduction/exhumation velocities, so that a continuous cycling of material in the subduction zone channel is indicated. In two blocks of eclogite and garnet blueschist an earlier amphibolite-facies history at 575-700 °C and 7-8 kbar can be documented, suggesting erosion of the base of the overlying intra-oceanic island arc. The fossil subduction zone studied in detail here is part of a much larger feature exposed at intervals around the perimeter of the Caribbean plate where the intra-oceanic arc has collided with North and South America. The continuous history documented here from before 120 Ma to after 60 Ma constrains regional plate tectonic models to incorporate a similarly uninterrupted continuous history of eastward movement of the Caribbean plate with respect to North and South America.

Krebs, M.; Schertl, H.-P.; Maresch, W. V.; Draper, G.



Potential of high resolution satellite imagery, remote weather data and 1D hydraulic modeling to evaluate flood areas in Gonaives, Haiti  

NASA Astrophysics Data System (ADS)

We present a feasibility study to explore potential of high-resolution imagery, coupled with hydraulic flood modeling to predict flooding risks, applied to the case study of Gonaives basins (585 km²), Haiti. We propose a methodology working at different scales, providing accurate results and a faster intervention during extreme flood events. The 'Hispaniola' island, in the Caribbean tropical zone, is often affected by extreme floods events. Floods are caused by tropical springs and hurricanes, and may lead to several damages, including cholera epidemics, as recently occurred, in the wake of the earthquake upon January 12th 2010 (magnitude 7.0). Floods studies based upon hydrological and hydraulic modeling are hampered by almost complete lack of ground data. Thenceforth, and given the noticeable cost involved in the organization of field measurement campaigns, the need for exploitation of remote sensing images data. HEC-RAS 1D modeling is carried out under different scenarios of available Digital Elevation Models. The DEMs are generated using optical remote sensing satellite (WorldView-1) and SRTM, combined with information from an open source database (Open Street Map). We study two recent flood episodes, where flood maps from remote sensing were available. Flood extent and land use have been assessed by way of data from SPOT-5 satellite, after hurricane Jeanne in 2004 and hurricane Hanna in 2008. A semi-distributed, DEM based hydrological model is used to simulate flood flows during the hurricanes. Precipitation input is taken from daily rainfall data derived from TRMM satellite, plus proper downscaling. The hydraulic model is calibrated using floodplain friction as tuning parameters against the observed flooded area. We compare different scenarios of flood simulation, and the predictive power of model calibration. The method provide acceptable results in depicting flooded areas, especially considering the tremendous lack of ground data, and show the potential of remote sensing information in prediction of flood events in this area, for the purpose of risk assessment and land use planning, and possibly for flood forecast during extreme events.

Bozza, Andrea; Durand, Arnaud; Allenbach, Bernard; Confortola, Gabriele; Bocchiola, Daniele



Upper Ocean Responses to Hurricane Frances in September 2004  

NASA Astrophysics Data System (ADS)

Three new autonomous ocean velocity and density profilers were deployed ahead of Hurricane Frances as it passed north of Hispaniola in September 2004. These EM-APEX floats (velocity sensing versions of Webb Research Corp APEX floats) were launched from a C-130. The EM-APEX floats measured T, S and V over the upper 500 m starting about a day before the storm's arrival. One EM-APEX float was directly under the track of the storm's eye, another EM-APEX float went in about 55 km to the right of the track (where the surface winds are strongest) and the third float was about 110 km to the right. The EM-APEX floats profiled for 10 hours from the surface to 200 m then continued profiling between 30 and 200 m with excursions to 500 m every half inertial period. After 5 days, the EM-APEX floats surfaced and transmitted the accumulated processed observations, then the floats profiled to 500 m every half inertial period until recovered early in October aided by GPS and Iridium. The float array sampled in unprecedented detail the upper-ocean momentum, turbulence and salt and heat changes in response to the hurricane. Rapid acceleration of inertial currents in the surface mixing layer (SML) to over 1 m/s produced vertical mixing by shear instability at the SML base, as indicated by low Richardson numbers and SML deepening from about 40 m to 120 m under the strongest wind forcing. Surface cooling of about 2.2 C was primarily due to the SML deepening and entrainment of colder water, with a small contribution from surface heat flux. Intense inertial pumping was observed under the eye, with vertical excursions of 50 m or more. Comparison with a 3-D numerical model of the ocean response to Frances' winds simulates accurately SML deepening and surface cooling as well as significant differences in maximum currents and heat content changes. These differences highlight the sensitivity of the ocean's response to both the specification of the wind field and the parameterization of stress under high wind speeds. In particular, the momentum flux into the ocean supports a drag coefficient that does not increase with wind speed as proposed by recent GPS dropsonde and wind-wave tank studies.

Sanford, T. B.; Price, J. F.; Webb, D. C.; Girton, J. B.



High-resolution Vertical Profiling of Ocean Velocity and Water Properties Under Hurricane Frances in September 2004  

NASA Astrophysics Data System (ADS)

In ONR's CBLAST Hurricane research program observations were made of the upper ocean's response to Hurricane Frances. Three EM-APEX floats (velocity sensing versions of Webb Research APEX floats) and two Lagrangian floats were deployed north of Hispaniola from a C-130 aircraft ahead of Hurricane Frances in September 2004. The EM-APEX floats measured T, S and V over the upper 500 m starting about a day before the storm's arrival. The Lagrangian floats measured temperature and salinity while following the three- dimensional boundary layer turbulence in the upper 40 m. One EM-APEX float was directly under the track of the storm's eye, another EM-APEX and two Lagrangian floats went in about 50 km to the right of the track (where the surface winds are strongest) and the third float was about 100 km to the right. The EM-APEX floats profiled for 10 hours from the surface to 200 m, then continued profiling between 35 and 200 m with excursions to 500 m every half inertial period. After 5 days, the EM-APEX floats surfaced and transmitted the accumulated processed observations, then the floats profiled to 500 m every half inertial period until recovered early in October aided by GPS and Iridium. The float array sampled in unprecedented detail the upper-ocean turbulence, momentum, and salt and heat changes in response to the hurricane. The buildup of surface gravity waves in advance of the storm was also observed in the velocity profiles, with significant wave heights of up to 11 m. Rapid acceleration of inertial currents in the surface mixing layer (SML) to over 1 m/s stimulated vertical mixing by shear instability at the SML base, as indicated by low Richardson numbers and SML deepening from about 40 m to 120 m under the strongest wind forcing. Surface cooling of about 2.5 C was primarily due to the SML deepening and entrainment of colder water, with a small contribution from surface heat flux. Intense inertial pumping was observed under the eye, with vertical excursions of 50 m or more. Comparison with a 3-D numerical model of the ocean response to Frances' winds reveals encouraging similarities in SML deepening and surface cooling as well as significant differences in maximum currents and heat content changes. These differences highlight the sensitivity of the ocean's response to both the specification of the wind field and the parameterization of stress under high wind speeds.

Sanford, T. B.; D'Asarp, E. A.; Girton, J. B.; Price, J. F.; Webb, D. C.



Initiatives of Application of the Bakun-Wentworth's Method for the Estimation of Macroseismic Parameters in the Northern South America and the Caribbean Region  

NASA Astrophysics Data System (ADS)

The assessment of location, magnitude and uncertainties of great historical earthquakes is a key issue for understanding the seismic potential and PSHA of a region. In the last years independent techniques using only macrosesismic data points have been developed as, for example, the approach of Bakun and Wentworth (1997) or BW. This method has been largely applied in different tectonic contexts (Bindi et al., 2013), in different UE international projects and in estimations of location, magnitude and epistemic uncertainties (Bakun et al., 2011). We focus on some regional calibration initiatives in Northern South America and areas of the Caribbean Region. BW has been calibrated by Palme et al. (2005) and Choy et al. (2012) for earthquakes of the Mérida Andes and the Venezuela Central Regions. As well, BW calibrations have been proposed for the interandean Valley in Ecuador (Beauval et al., 2010), in the Hispaniola (Bakun et al, 2012) and for the northeastern Caribbean region (ten Brink et al., 2011). Preliminary BW calibration for the southeastern region of Cuba has been proposed by Gómez-Capera et al. (2012). Applications to historical earthquakes in Cuba have given encouraging results mainly for offshore events and are presented in the present study. We also present preliminary results for some earthquakes that have been recently studied in literature as for example the historical earthquakes of 1743 (Salcedo Hurtado and Gómez-Capera in press) and 1785 (Salcedo Hurtado and Castaño Castaño, 2011) which occurred close to Bogotá, BW method and intensity relationship of the literature were used. We present comparisons and sensibility analysis of the different relationships obtained in the region as well as uncertainty assessment. We also note that the magnitude parameter depends strongly on the regional calibration. Because of the availability of new macroseismic studies in Colombia (Servicio Geológico Colombiano y Universidad Nacional de Colombia, 2013; available online inórica/), Venezuela ( and Caribbean Region, in the future it is expected to propose models for macroseismic intensity attenuations of regional character especially in Colombia and in Venezuela in the Cumaná region. This region has a rich earthquake history. In this topic of the regional calibration of intensity attenuation relationships, the situation is challenging because several historical and recent earthquakes in this region are attributed to subduction zones. It is therefore necessary to involve focal depth. This is still an open problem.

Gomez Capera, A.; Bindi, D.; Cifuentes, H.; Choy, J.; Chuy Rodriguez, T.; Garcia, J.; Massa, M.; Palme, C.; Pierristal, G.; Salcedo Hurtado, E.; Sanchez Vasquez, A.



From 2012 HAITI-SIS Survey: thick-skin versus thin-skin tectonics partitioned along offshore strike-slip Faults-Haïti  

NASA Astrophysics Data System (ADS)

The characterization of the deformation along large strike-slip fault-systems like transpressive boundaries between N. Caribbean/N America is a challenging topic, which requires a multi-scale approach. Thanks to Haiti-sis new data, the precise description of the fault segmentation pattern, the sedimentogical distribution, the uplift/subsidence rates, the along-fault and intra-basin fluids circulations, allows to actualize the evolution of the deformation history up to present-day . All the co-seismic surface to near-surface events, have to be also identified in order to integrate geophysical solutions for the earthquake, within the present-day geological and structural pattern. These two approaches, ranging from geological to instantaneous time-scales have been used during multi-tools Haiti-Sis oceanographic survey, allowing to document and image these different aspects at a large scale. The complex strike-slip North Caribbean boundary registered significative stress partitioning. Oblique convergence is expressed by along-strike evolution; from rifted segments (Cayman Through) to transpressive ones (Haiti, Dominican Rep.), to subduction (Porto Rico). In the Haiti-Sis survey, we acquired new offshore data surrounding the active fault areas, in the Gonâve Bay, the Jamaica Channel and along Southern Peninsula. Mapping the sea-floor, and HR seismic acquisition were our main objectives, in order to characterize the fault and fold architecture, with a new delineation of active segments. Offshore piston cores, have been used as representative of the modern basin sedimentation, and to document the catastrophic events (earthquakes, massive flood or sudden destabilization of the platform ) represented by turbiditic or mass-flow sequences, with the objective to track the time recurrence of seismic events by dating some of these catastrophic sediment deposition. At surface, the other markers of the fault activity are linked with along-fault permeability and fluid circulation pathway changes. Geochemical signature and temperature of the fluids and gas, change drastically depending on location and depth provenance. Our first results show that 1) the present-day EPGF geometry results from oblique shortening processes along different segments of the fault. Deep basins previously localized south and north of the fault are inverted at different degrees, 2) the Gonâve Island is only the emerged part of a NW-SE, either growing large " anti-formal stack" or basement inversion responsible for the large present-day fold amplitude, or both of them successively. It separates two sub-basins South and North Gonâve with independant sedimentary and deformation evolution 3) the Jeremie Basin probably has a specific long-living evolution, allowing to precise the geodynamic evolution of the Western Hispaniola Margin.

Ellouz, N.; Leroy, S. D.; Momplaisir, R.; Mercier de Lepinay, B.



Petrology and geochemistry of the Late Cenozoic volcanic rocks of the Dominican Republic  

SciTech Connect

Late Cenozoic rocks of Hispaniola are subdivided into two petrographically and geochemically contrasting series, a calc-alkaline series (CA-series), and a mafic alkaline series (MA-series). The CA-series are basalts, basaltic andesites, trachyandesites, and dacites occurring in several eruptive centers in the southern part of the Cordillera Central of the Dominican Republic. MA-series basalts are alkali-olivine basalts and limburgitic basalts occurring in the San Juan Valley of the Dominican republic and in the Cul de Sac of south central Haiti. Olivine, clinopyroxene, amphibole, mica, feldspar, and titanomagnetite were analyzed for major element chemical composition. MA-series basalts are slightly to moderately silica undersaturated, have high TiO2 (>1.5%) and MgO (>5.0%) and moderately high total alkalis (>2.0%). MA-series basalts are enriched in K, Rb, Sr, Ba, U, Th and LREEs with Ba/La ratios around 0.98. REE patterns are fractionated (chrondrite normalized La/Yb ratios around 62, and La/Sm ratios around 6). HFS elements Zr, Hf, Nb, and Ta are high resembling intraplate basalts. 86SR/87SR ratios are high (0.7060-0.7070) with low Rb/Sr ratios (0.03 to 0.15). Basalts, basaltic andesites, trachyandesites, and dacites of the CA-series show low MgO (<5.0%) and TiO2(<2.0%), and moderately high total alkali contents (2 to 7%). Enrichment is seen in K Rb, Sr, Ba, Th, U, and LREEs with Ba/La ratios as high as 5.6 REE patterns are fractionated to a lesser degree compared to the MA-series (chondrite normalized La/Yb around 23, and La/Sm ratios less than 5). HFS elements are lower resembling typical island arc volcanic rocks. CA-series have 87Sr/86Sr ratios (.7043-.7053), with low Rb/Sr ratios as in the MA-series.

Vespucci, P.D.



Evolution of Type 2 Vaccine Derived Poliovirus Lineages. Evidence for Codon-Specific Positive Selection at Three Distinct Locations on Capsid Wall  

PubMed Central

Partial sequences of 110 type 2 poliovirus strains isolated from sewage in Slovakia in 2003–2005, and most probably originating from a single dose of oral poliovirus vaccine, were subjected to a detailed genetic analysis. Evolutionary patterns of these vaccine derived poliovirus strains (SVK-aVDPV2) were compared to those of type 1 and type 3 wild poliovirus (WPV) lineages considered to have a single seed strain origin, respectively. The 102 unique SVK-aVDPV VP1 sequences were monophyletic differing from that of the most likely parental poliovirus type 2/Sabin (PV2 Sabin) by 12.5–15.6%. Judging from this difference and from the rate of accumulation of synonymous transversions during the 22 month observation period, the relevant oral poliovirus vaccine dose had been administered to an unknown recipient more than 12 years earlier. The patterns of nucleotide substitution during the observation period differed from those found in the studied lineages of WPV1 or 3, including a lower transition/transversion (Ts/Tv) bias and strikingly lower Ts/Tv rate ratios at the 2nd codon position for both purines and pyrimidines. A relatively low preference of transitions at the 2nd codon position was also found in the large set of VP1 sequences of Nigerian circulating (c)VDPV2, as well as in the smaller sets from the Hispaniola cVDPV1 and Egypt cVDPV2 outbreaks, and among aVDPV1and aVDPV2 strains recently isolated from sewage in Finland. Codon-wise analysis of synonymous versus non-synonymous substitution rates in the VP1 sequences suggested that in five codons, those coding for amino acids at sites 24, 144, 147, 221 and 222, there may have been positive selection during the observation period. We conclude that pattern of poliovirus VP1 evolution in prolonged infection may differ from that found in WPV epidemics. Further studies on sufficiently large independent datasets are needed to confirm this suggestion and to reveal its potential significance.

Hovi, Tapani; Savolainen-Kopra, Carita; Smura, Teemu; Blomqvist, Soile; Al-Hello, Haider; Roivainen, Merja



Middle America - Regional Geological Integrity, Hydrocarbon Implications.  

NASA Astrophysics Data System (ADS)

Dogma holds that the Caribbean Plate and its islands formed in the Pacific and comprise oceanic crust and intra- oceanic arc rocks. Middle America, between N and S America, manifests a regional, N35°E and N60°W tectonic fabric. The NE trend results from Triassic-Jurassic reactivation of Palaeozoic convergent structures as extensional faults during Pangean rifting and commencement of N America drift. The NW trend parallels major inter-continental faults and oceanic fractures along which extension and drift occurred. Triassic-Jurassic red beds accumulated in the NE trending, intra-continental rifts of N, S and Central America. Proximal extended continental margins subsided to accommodate thick Cretaceous carbonate sections (Florida - Bahamas, Campeche, Nicaragua Rise). Distal margins formed continental blocks flanked by seaward-dipping wedges. Seismic and drilling in basins along the eastern seaboard of N America (Baltimore Canyon to Blake Plateau) document Triassic-Jurassic red beds overlain by salt and carbonates. Hydrocarbons are present. In Middle America the Gulf of Mexico remained "intra-continental", surrounded by continental blocks (N America, Maya, Florida). The area further south experienced greater extension, manifest by diverging oceanic fracture patterns to the east and west. Seismic data over the Caribbean Plateau reveal deep architecture of NE trending highs flanked by dipping wedges of reflections, similar to eastern N America distal basins. DSDP drilling calibrated the overlying smooth seismic Horizon B" as recording Cenomanian basalts. Smoothness, great lateral extent and coeval exposed sections with palaeosols followed by shallow marine carbonates suggest they were sub-aerial. Adjacent, rough seismic Horizon B" probably records top of submarine, serpentinized mantle. Seismic over the plateau also reveals features identical to drilled Sigsbee salt diapirs of the Gulf of Mexico. The regional tectonic fabric demonstrates a shared geological history of Middle American geographic components, negates rotations of the Maya and Chortis blocks required by Pacific models and shows that the Caribbean Plate formed in place. Regional geologic and seismic data indicate that much of "oceanic" Middle America is in fact underpinned by extended continental crust. Salt is present, and probably Jurassic, Cretaceous and Tertiary source rocks also. Oil is seen on Puerto Rico, Hispaniola, Jamaica, Cuba, Belize, Guatemala, Honduras, Nicaragua, Costa Rica and Panama. Prolific hydrocarbon provinces exist in the Gulf of Mexico and along northern S America. The submarine areas in between have significant hydrocarbon potential.

James, K. H.



Neogene-Quaternary tectonics along the North Caribbean transform fault, Cuba  

NASA Astrophysics Data System (ADS)

The Neogene to Recent North Caribbean (Oriente) Transform Fault (OTF) off the coast of southern Cuba is part of the northern Caribbean transform fault system. It has affected the southern Sierra Maestra mountain range, SE Cuba, and portrays the dynamics and tectonic evolution of the southern Cuban coast in the boundary zone between the Caribbean and North American plates. The region has been affected by historical earthquakes and shows many structures due to brittle deformation in Neogene to Pleistocene shallow-water limestones. Present-day structures vary along strike of the OTF, with dominant transpression in the east and transtension in the west. The focal mechanisms of historical earthquakes are in agreement with dominant ENE-WSW compression found onland. Neogene-Pleistocene limestones are deformed, faulted, fractured, and contains calcite- and karst-filled extension gashes. Type and orientation of the principal normal paleostresses vary along strike in accordance with observations of large-scale submarine structures at the southern Cuban continental margin. Deformation phase D1 comprises N-S extension, exemplified mainly by karst-filled extensional veins and normal faults. We correlate this deformation with the regional kinematics in the Caribbean realm, imposed by the opening of the Cayman trough and the disruption between Cuba and Hispaniola. D2 and D3 comprise NE-SW to nearly N-S and subsequent NW-SE-directed compression and generated conjugate Mohr shears that correlate with strike-slip movement along the main fault to the south. These phases are also associated with a transpressional tectonic regime in the submarine Santiago Deformed Belt and with deformation processes along the Oriente Deep, both located off the southern Cuban coast. D4 reflects ENE-WSW to E-W-directed compression and corresponds to reactivation of sinistral strike-slip faults and formation of Riedel shears, consistent with stress orientations deduced from earthquake focal mechanisms. The present-day stress field in the Neogene to Pleistocene deposits in the southern Sierra Maestra evolved from oblique collision to transcurrent movement with a combination of transpression in the east and transtension in the west.

Rojas-Agramonte, Y.; Neubauer, F.; Handler, R.; Garcia-Delgado, D. E.; Friedl, G.; Delgado-Damas, R.



[Haitian migration to Santo Domingo].  


This work examines the history of Haitian migration to the Dominican Republic, the central role of Haitian migration in Dominican society, working conditions of Haitian migrants in the Dominican Republic, and the relationship of the migration to economic development on the island of Hispaniola. Lack of data, the difficulty of measuring illegal movement, and the problem of defining Haitians in Santo Domingo have impeded understanding of migration to the Dominican Republic. It is believed by many authorities that Haitian migration to Santo Domingo is considerable and perhaps exceeds that to the US. Haitian migration to the Dominican Republic began after 1915 with the fall of the Haitian president, a worsening of economic conditions partly caused by stagnation in the agricultural sector, and the newly dominant role of the US in Haitian economic affairs. The Great Depression of the 1930s was a direct antecedent of the massacre of Haitians by Dominican police in which some 30 thousand persons were killed; the economic recession of the early 1980s has also caused an outburst of antiHaitian feeling in the Dominican Republic although 80% of laborers in the sugar industry are Haitians. Sugar is extremely important to the Dominican economy: in 1974, sugar covered 12% of cultivated land, produced 40% of foreign exchange earnings, and was responsable for 21% of taxable income. Dominicans however refuse to work in sugar plantations under the current technological. conditions and wage system. Although the government periodically demands the Dominicanization of the sugar work force, no such changes have been made. Sugar will probably continue to play a decisive role in the generation of foreign exchange despite introduction of more technologically advanced sectors which benefit from better prices in the international market. Possibilities of mechanizing sugar production in the Dominican Republic appear remote, and failure to modernize an important sector of the economy has explained migration of unskilled labor from poorer countries in more than 1 case. Under such circumstances, the extremely poor working conditions of Haitians in the Dominican Republic are not surprising. A 1983 investigation by the International Labour Organization indicated that salaries were low, that a large proportion was routinely diverted from the migrants, that hours of work were long with no regular rest and few days off, that few workers had any contractual protection, that forced labor recruitment occurred, that a rigid system of vigilance with armed patrols was used to keep the immigrants in the work camps, and that living conditions were substandard--in short, that Haitian workers were "neo-slaves". In addition, the Dominicans consider themselves racially and culturally superior to Haitians. The Haitian government, in return for payments from the Dominican Republic, does nothing to stop the abuses. PMID:12179414

Latortue, P R



Latest Pleistocene to Holocene Evolution of the Baie de Port au Prince, Haiti  

NASA Astrophysics Data System (ADS)

The Baie de Port au Prince (BPP) is adjacent a restraining segment of the sinistral Caribbean-North America plate boundary and is therefore situated between converging high-relief thrust systems, the Massif Selle (Peninsula Range) to the south and the Chaine de Matheux (Hispaniola highlands) to the north. To evaluate neotectonic deformation, seismic hazards and sedimentation patterns for the BPP, six gravity cores were studied within the framework of chirp profiles collected from the R/V Endeavor in 2010. The cores were recovered from 76 m to 148 m of water depth sampling sediment from the carbonate platform that rims the BPP and from the slope. We studied the biostratigraphy (foraminifers, nannoplankton), geochemical elemental composition and physical properties of the sediment. An age model from the last glacial to the present (~20 ka BP) was derived from radiocarbon. Nannoplankton biostratigraphy provide constraints on the late Pleistocene. The BPP is 150 m maximum water depth and is rimmed by an ~30 m deep carbonate platform that has undergone dissolution. Terraces characterize the sub-bottom topography to the NE. This topography was covered by sediment during at least one relative sea-level cycle. Sediment progradation and mass-wasting on the northern and southern flanks of the BPP respectively, occurred during the latest Pleistocene low stand (~20 ka BP). Increased sedimentation from 0.2 mm/year to 0.8 mm/year occurred from 14.2 ka BP to 9.5 ka BP. This period also corresponds with a global rapid rate in sea-level rise from -94 m to -37 m. A basin wide acoustically transparent layer of sediment ~10 m thick covered the BPP. Mass-wasting, microfaulting, fluidization and turbidites caused by erosion triggered by pre-historic earthquakes possibly associated with EPG transform fault are found in the cores. One such deposit is possibly associated to the 2010 earthquake and another to an unconformable surface that separates early- from late-Holocene sediment on the slope. The late Pleistocene sediment is laminated and microfossils assemblages reveal sediment reworking and shallow water depths. Normal marine sedimentation resumed from ~14 ka BP to the present. The climate was characterized by wet or high discharge intervals noted by an influx of wood fragments and sediment most likely derived from land (>Si weight %, Al%, Fe% and Cu ppm). Wet periods were less frequent in the Holocene. The late Holocene trend is to dryer climate consistent with previous studies of the region. Evaporation is manifested by an increase in subhedral gypsum coated in calcite. Limited chirp profiles across the BPP suggest subsidence to the south. Ages from the base of the cores will verify this possibility. Coseismic 2010 uplift was documented in the southwestern part of the Leogane delta, an area that has no evidence of long-term uplift. Chirp profiles and multibeam bathymetry close to this uplift, show a deepening of the sea-floor suggestive of ongoing subsidence. More studies are needed to better understand the long-term patterns of subsidence and uplift in this region.

Rios, J. K.; McHugh, C. M.; Seeber, L.; Blair, S.; Sorlien, C. C.



On the Changes of the Hydrological Balance of Caribbean Lakes - Modeling and Observations  

NASA Astrophysics Data System (ADS)

The Enriquillo and Sumatra are saltwater lakes located in a rift valley that is a former marine strait created around 1 million years ago when the water level fell and the strait was filled in by river sediments, they are the largest lakes in the Dominican Republic and Haiti, respectively, with Lake Enriquillo being the lowest point in the Caribbean. The lakes, part of the Enriquillo closed water basin in the southwestern region of the island of La Hispaniola, have been experiencing dramatic changes in total lake-surface area coverage during the period 1980-2012. The size of the lakes was determined using remote sensing images (NASA-LANDSAT) analyzed with geographic information system (GIS) at different times during the available record. The size calculation for Lake Enriquillo shows a lake surface area of approximately 276 km2 in 1984 that gradually decreased to 172 km2 in 1996. After a period of fluctuations between 1996 and 2001, the surface area of the lake reaches its lowest point in 2004, at 165 km2. Beginning in 2004, the recent growth of the lake begins and reaches its 1984 size in 2006. Based on surface area measurement for December 2009, the lake size is 333 km2, 17% larger than in 1984 and almost double than in 2004. Sumatra sizes at both ends of the record are 115.96 km2 in 1984 and 134.26 km2 in 2011, an overall 15.8% increase in 27 years. Because the lakes are mostly latitudinally restricted by topography, most of the size changes occur on the southeastern side of Lake Enriquillo, with some growth on the western tip. Determining the causes of lake surface area changes is of extreme importance due to the environmental, social, and economic consequences. The goal of this study is to quantify the changing water balance in these lakes using satellite and ground observations and regional atmospheric modeling. Analyses of environmental variables in the region reflect a hydrological unbalance of the lakes due to changing regional hydro-climatic conditions. Historical data show precipitation, land surface temperature and humidity, and sea surface temperature (SST), increasing all over the past decades. Salinity levels have also been decreasing by more than 30% from baseline levels. We hypothesized that the increases in SSTs may be leading to increases in regional moisture content which leads to decreases in evaporation capacity from the lakes, and simultaneously to increases in fresh water production in the neighboring sierras. A network of rain and fog gauges along the high sierras reflects growing cloud montane forests, with significant increase in water production. Results from a high-resolution mesoscale atmospheric modeling clearly reflect increases in the amount of liquid water content in the vertical column as function of changing regional climate conditions.

Comarazamy, D.; Gonzalez, J.; Glenn, E.; Leon, Y.; Brito, D. R.



The Role of Science and Engineering in Rebuilding a More Resilient Haiti (Invited)  

NASA Astrophysics Data System (ADS)

Rebuilding a more disaster-resilient Haiti is the defining challenge in the wake of the devastating magnitude-7 earthquake that struck in January. The contrasting experience of Chile, which weathered a magnitude-8.8 earthquake in April with casualties in the hundreds, teaches us that building resilience is an achievable and desirable goal given suitable investments and governance. Scientists and engineers have much to contribute, but doing so requires effective mechanisms to enable them to inform the rebuilding process. The international donor community has been a key point of engagement since their funds provide the opportunity to build new schools, hospitals, critical infrastructure and housing that will not fail in the next disaster. In advance of a gathering of international donors at the end of March, the U.S. National Science and Technology Council’s interagency Subcommittee on Disaster Reduction convened a workshop that brought together over 100 scientists, engineers, planners, and policymakers, including a delegation of Haitian government officials and academics. Hosted by the University of Miami and organized by the Incorporated Research Institutions for Seismology, the workshop was co-sponsored by the U.S. Department of State, U.S. Agency for International Development (USAID), and United Nations International Strategy for Disaster Reduction with support from NASA, the National Science Foundation, and the U.S. Geological Survey (USGS). Key findings from the workshop covered the need to adopt and enforce international building codes, to use hazard assessments for earthquakes, inland flooding, and landslides in the planning process, and the central importance of long-term capacity building. As an example of one science agency’s contributions, the USGS informed the initial response by rapidly characterizing the earthquake and delivering estimates of population exposure to strong shaking that were used by humanitarian organizations, aid agencies, and the Haitians themselves. In the ensuing weeks, the USGS tracked aftershocks and issued statements with probabilities of future earthquakes. Early on, the U.S. Southern Command made it possible to put an advance team of engineers and a USGS seismologist on the ground in Haiti. That initial team was followed by the first major deployment of a USGS/USAID Earthquake Disaster Assistance Team, which evolved from the long-standing partnership between these two agencies. EDAT activities included field assessment of faulting, coastal uplift, and landslides; seismometer deployments for aftershock recording and characterization of ground shaking amplification; and development of a probabilistic seismic hazard map for Haiti and the whole island of Hispaniola. The team’s efforts benefited greatly from collaboration with Haitian colleagues with knowledge transfer occurring in both directions. The effort also benefited from significant remote sensing acquisitions, which helped to target field activities and constrain fault rupture patterns. Although the products have been put to use in Haiti, it still remains to turn hazard assessments into tools that can be used for effective planning, building code development and land-use decisions.

Applegate, D.



Recommendations for the establishment of the seismic code of Haiti  

NASA Astrophysics Data System (ADS)

Haiti, because of his seismicity associated with plate boundary and several faults that cross the island of Hispaniola (Haiti-Dominican Republic), has been affected in the past by major earthquakes, which have caused loss of life and damage or considerable structural collapses (ex. 1771, 1842), sometimes the destruction of the cities. The recent earthquake of January 12, 2010, was the most destructive earthquake that any country has experienced in modern times, when we measure the number of people killed with respect to the population of a country (Cavallo et al. 2010). It's obvious that the major causes of theses losses are the lack of awareness of the population about the earthquakes, the absence of seismic code and quality control of the building. In this paper, we propose some recommendations for the establishment of the seismic code of Haiti in order to decrease physical and social impacts of earthquakes in the future. First of all, we present a theoretical part of concepts and fundamental elements to establish a seismic code, such as: description of the methodology for seismic hazard's assessment, presentation of the results in terms of acceleration maps for the whole country (in rock sites) and Uniform Hazard Spectrum (UHS) in the cities, and the criteria for soil classification and amplification factors for including site's effects, equivalent forces, etc. Then, we include a practical part where calculations and comparisons of five seismic codes of different countries (Eurocode 8, Spain, Canada, United States and Dominican Republic) are included, in order to have criteria for making the proposals for Haiti. Using the results of Benito et al (presented in this session S10) we compare the UHS in different cities of Haiti with the response spectrum derived from the application of the spectral shapes given by the aforementioned codes. Furthermore, the classification of soils and buildings have been also analyzed and contrasted with local data in order to propose the more suitable classification for Haiti. Finally, we have proposed a methodology for the forces estimation providing the values of the relevant coefficients. References: EN 1998-1:2004 (E): Eurocode 8, Design of structures for earthquake resistance, Part 1(General Rules, seismic actions and rules for buildings), 2004. -MTPTC, (2011). Règles de calcul intérimaires pour les bâtiments en Haïti, Ministère des Travaux Publics, Transports et Communications, Février 2011, Haïti. -NBCC 2005: National Building Code of Canada, vol1, National Research Council of Canada 2005. -NCSE-02: Norma de construcción sismorresistente de España. BOE num.244, Viernes 11 Octubre 2002. -NEHRP, 2009. Recommended Provisions for Seismic Regulations for new Buildings and Other Structures, FEMA P-750, February, Part 1 (Provisions) and Part 2 (Commentary). -R-001 (2011): Reglamento para el análisis y diseño sísmico de estructuras de República Dominicana. Decreto No. 201-11. Ministerio de Obras Públicas y Comunicaciones.

Pierristal, G.; Benito, B.; Cervera, J.; Belizaire, D.



Mineral and whole rock compositions of peridotites from Loma Caribe (Dominican Republic): insights into the evolution of the oceanic mantle in the Caribbean region  

NASA Astrophysics Data System (ADS)

Several mantle peridotite massifs crop out as isolated dismembered bodies in tectonic belts along the northern margin of the Caribbean plate, especially in Cuba, Guatemala, Jamaica, Hispaniola and Puerto Rico. Among these bodies, the Loma Caribe peridotite forms the core of the Median Belt in central Dominican Republic and is considered to have been emplaced in Aptian time as result of the collision between an oceanic plateau (the Duarte plateau terrane) and the primitive Caribbean island arc. This peridotite massif is mainly composed of clinopyroxene-rich harzburgite, harzburgite, lherzolite and dunite which mainly have porphyroclastic texture with strongly deformed orthopyroxene porphyroclasts, as commonly observed in ophiolitic mantle tectonites. Mg# [100*Mg/(Mg+Fe2+)] of olivine increases from lower values in lherzolite (89-90), to higher values in harzburgite (89-91) and dunite (91-92). Orthopyroxene in harzburgite has higher Mg# (91-92) and lower Al2O3 (0.89 to 1.12 wt.%) than in lherzolite (Mg# = 89-91; Al2O3 = 2.4-3.5wt.%), similarly to clinopyroxene (Mg# = 94-95 and Al2O3 = 0.89-1.10 wt% in harzburgite, versus Mg# = 86-94 and Al2O3 = 2.3-4.0 wt% in lherzolite). Cr# [Cr/(Cr+Al)] of spinel spans from 0.30 in lherzolite to 0.88 in dunite. These variations in terms of Mg# in olivine and Cr# in spinel overlap the mineral compositions in both abyssal and supra-subduction zone peridotites. The sample/chondrite REE concentrations of peridotites are variable (0.002 < LREE chondrite-normalized < 0.11 and 0.002 < HREE chondrite-normalized < 1.02) and their HREE contents generally reflect the clinopyroxene proportions in the samples, i.e. harzburgite has lower HREE abundances than lherzolite. These trace element abundances are transitional between those of highly depleted supra-subduction peridotites from ophiolites in eastern Cuba and those of fertile mantle rocks in ultramafic massifs from Puerto Rico. Chondrite-normalized patterns are U-shaped (i.e., relatively rich in LREE) with steep fractionated HREE segments in harzburgite and hump-shaped MREE segments in lherzolite. Peridotites are enriched in the most incompatible trace elements (Cs, Rb, Ba, Th, U) and Pb, and show negative anomaly in Nb and Ta. HREE contents in whole rock indicate that the Loma Caribe peridotites are residues after moderate to high degrees (10-25%) of fractional partial melting in the spinel stability field. The relative enrichment in incompatible elements (e.g., LILE and LREE) in these rocks probably reflects the capture of percolating melt fractions along grain boundaries or as micro-inclusions in minerals and resulted from interaction of melting residues with ascending melts. We interpret the Loma Caribe peridotite as a portion of heterogeneous sub-oceanic mantle lithosphere generated in Jurassic-Cretaceous time, which has been modified at a supra-subduction zone environment related to the Cretaceous Greater Antilles arc.

Marchesi, C.; Garrido, C. J.; Proenza, J. A.; Konc, Z.; Hidas, K.; Lewis, J.; Lidiak, E.



Seismic rupture process of the 2010 Haiti Earthquake (Mw7.0) inferred from seismic and SAR data  

NASA Astrophysics Data System (ADS)

On January 12th 2010 at 21:53, the Port-au-Prince - Haiti region was struck by an Mw7 earthquake, the second most deadly of the history. The last seismic significant events in the region occurred in November 1751 and June 1770 [1]. Geodetic and geological studies, previous to the 2010 earthquake [2] have warned to the potential of the destructive seismic events in that region and this event has confirmed those warnings. Some aspects of the source of this earthquake are nonconsensual. There is no agreement in the mechanism of rupture or correlation with the fault that should have it generated [3]. In order to better understand the complexity of this rupture, we combined several techniques and data of different nature. We used teleseismic body-wave and Synthetic Aperture Radar data (SAR) based on the following methodology: 1) analysis of the rupture process directivity [4] to determine the velocity and direction of rupture; 2) teleseismic body-wave inversion to obtain the spatiotemporal fault slip distribution and a detailed rupture model; 3) near field surface deformation modeling using the calculated seismic rupture model and compared with the measured deformation field using SAR data of sensor Advanced Land Observing Satellite - Phased Array L-band SAR (ALOS-PALSAR). The combined application of seismic and geodetic data reveals a complex rupture that spread during approximately 12s mainly from WNW to ESE with average velocity of 2,5km/s, on a north-dipping fault plane. Two main asperities are obtained: the first (and largest) occurs within the first ~ 5sec and extends for approximately 6km around the hypocenter; the second one, that happens in the remaining 6s, covers a near surface rectangular strip with about 12km long by 3km wide. The first asperity is compatible with a left lateral strike-slip motion with a small reverse component; the mechanism of second asperity is predominantly reverse. The obtained rupture process allows modeling a coseismic deformation which is in agreement with the deformation field measured by InSAR. [1] Bakun W, Flores C, Brink U, 2012 Significant Earthquakes on the Enriquillo Fault System, Hispaniola, 1500-2010: Implications for Seismic Hazard. Bul. Seis. Soc. of America, 102(1):18-30. [2] Dixon, T. et al., 1998. Relative motion between the Caribbean and North American plates and related boundary zone deformation based on a decade of GPS observations. J. Geophys. Res. 103, 15157-15182. [3] Mercier de Lépinay, B., Deschamps, A., Klingelhoefer, F., Mazabraud, Y., Delouis, B., Clouard, V., Hello Y., Crozon, J., Marcaillou, B., Graindorge, D., Vallée M., Perrot, J., Bouin, M., Saurel, J., Charvis, Philippe, C. and St-Louis, 2011. The 2010 Haiti earthquake: A complex fault pattern constrained by seismologic and tectonic observations, Geoph. Res. Let., 30, L22305 [4] Caldeira B, Bezzeghoud M, Borges JF., 2009 DIRDOP: a directivity approach to determining the seismic rupture velocity vector. J. of Seis.. 2009;14(3):565-600.

Santos, Rúben; Caldeira, Bento; Borges, José; Bezzeghoud, Mourad



Near-field tsunami inferred from numerical modeling of medieval overwash at Anegada, British Virgin Islands  

NASA Astrophysics Data System (ADS)

In a comparison among numerical models of storms and tsunamis, only tsunami waves of nearby origin manage to wash over an area where coral heads of medieval age are scattered hundreds of meters inland from the north shore of Anegada, British Virgin Islands. This low-lying island faces the Puerto Rico Trench 120 km to the north. The island's north shore, fringed by a coral reef 100-1200 m offshore, displays geological evidence for two levels of overwash. The medieval overwash, dated to AD 1200-1450, was the higher one. It is evidenced by scores of coral boulders scattered hundreds of meters inland. Some of them crossed the area of the modern storm berm at Soldier Wash, continued across a broad limestone rise 3-4 m above sea level, and came to rest on lower ground farther inland. Coral heads in four other areas, also medieval or older, came to rest hundreds of meters inland from beach ridges now 2-4 m above sea level. The later, lower-elevation overwash, dated to AD 1650-1800, laid down a sheet of sand and shell that extends as much as 1.5 km inland. The hypothetical causes for each event, tested by numerical modeling, include (1) category IV and V hurricanes that differ in surge and wave heights; (2) the 1755 Lisbon earthquake or hypothetical medieval predecessor, at M 8.7 and M 9.0; (3) M 8.4 thrust earthquake along the Puerto Rico Trench between Hispaniola and Anegada; (4) M 8.7 thrust along the Puerto Rico Trench between Tortola and Antigua; (5) M 8.0 earthquake from normal faulting on the outer rise north of Anegada. The model output includes extent of onshore flooding, depth and velocity of overland flow, and energy lost by tsunami and hurricane waves as they cross the reef and continue across a shallow subtidal flat to Anegada's north shore. For the medieval overwash, the modeling is most conclusive in testing various explanations for the coral boulders inland of Soldier Wash. The simulated hurricane waves do not wash inland of the storm berm; the height of storm surge level is limited by deep water offshore, and the waves lose energy by breaking on the reef. As for the hypothesized tsunami sources, the Soldier Wash evidence is explained only by the M 8.7 interplate-thrust source along the eastern Puerto Rico Trench (4) or the outer-rise source north of Anegada (5). The M 8.7 interplate-thrust source may be inconsistent with recent GPS measurements [1], in which case the likely source is normal faulting on the outer rise (L = 132 km, W = 45 km, depth = 7.5 km, dip = 60°, strike = 110°, rake = -90°, slip = 7.1 m). The 1755 Lisbon tsunami may explain the sand-and-shell sheet from 1650-1800, with two caveats: (1) the sheet extends farther inland than does the modeled inundation from a Lisbon source smaller than M 9.0; and (2) neither of the Lisbon sources tested corresponds to mapped faults offshore Iberia (the modeled Lisbon sources strike NNW-SSE to account for flooding and damage elsewhere in the Caribbean [2]). In the hurricane models, the reef and the subtidal flats behind it dissipate too much wave energy from the storms to explain even the low-elevation overwash of 1650-1800. COMPANION ABSTRACTS: Geological evidence overview (Atwater), coral-boulder ages (Weil Accardo). REFERENCES: [1] GRL 39 (2012), L10304. [2] Marine Geology (2009), 264, 109-122.

Wei, Y.; Ten Brink, U. S.; Atwater, B. F.; Tuttle, M. P.; Robert, H.; Feuillet, N.; Jennifer, W.; Fuentes, Z.



Seismic Hazard in Haiti: A Geologic Perspective  

NASA Astrophysics Data System (ADS)

The catastrophic M 7.0 earthquake that occurred in Haiti on 12 January 2010 highlighted the hazard associated with the Caribbean-North American plate boundary in Hispaniola. Detailed analysis and modeling of geologic, geodetic, and seismologic data showed that most of the moment release occurred on a previously unidentified, north-dipping, blind thrust fault (now named the Léogâne fault), which is north of the plate-bounding, left-lateral Enriquillo-Plantain Garden fault (EPGF). The result that the Léogâne fault was the source of the 2010 earthquake implies that the EPGF remains a significant hazard and raises the question of other potential seismic sources near Port-au-Prince (PaP). Following the earthquake, we mapped Quaternary traces of the EPGF in the field using satellite imagery, aerial photography, and LiDAR data. We identified three paleoseismic study sites along the EPGF: the Jean-Jean and Marianne sites southwest of PaP along the Momance section of the EPGF and the Riviére Grise site southeast of PaP along the Dumay section. Trenches at the Jean-Jean site show fault strands breaking nearly to the ground surface, but that did not move in the 2010 earthquake. We collected radiocarbon samples from faulted strata that we anticipate will provide constraints on the age of the most recent surface rupture. We also identified a buried channel deposit that is left-laterally offset a minimum of 3 m, and collected radiocarbon samples to constrain its age. In a natural stream cut at the Marianne site, we documented three colluvial wedges, and collected samples for optically stimulated luminescence (OSL) dating that we anticipate will provide age constraints on the three most recent earthquakes. At Riviére Grise we documented evidence for three surface ruptures in a fluvial terrace deposit, and collected OSL samples to constrain their ages. Our preliminary geomorphic analysis of a belt of low hills north of the EPGF and east of PaP suggests that these hills are young folds likely underlain by blind thrust faults. Reconnaissance field observations show that the hills are cored by folded alluvial-fan deposits of probable Quaternary age and that the folding defeated north-flowing drainages and ponded lacustrine sediment on the south flank of the folds. Radiocarbon analyses of charcoal samples collected from ponded sediments will help to constrain the age of recent deformation. These blind thrust faults are potentially additional earthquake sources that should be included in seismic hazard assessments for PaP. In our reconnaissance along the Matheux-Neiba fault north of PaP we found only weak evidence of recent deformation, and while this fault system may also be a potential earthquake source, its rate of activity is much lower than the rate on the EPGF. Because the EPGF adjacent to PaP did not rupture in 2010, and has not ruptured in at least 240 years, considerable strain remains to be released in a future earthquake, and this fault still poses a major hazard to densely populated parts of Haiti, including Port-au-Prince.

Prentice, C. S.; Crone, A. J.; Gold, R. D.; Briggs, R. W.; Narcisse, R.



Late Cretaceous to Middle Eocene Geological Evolution of the Northwestern Caribbean - Constraints from Cuban Data  

NASA Astrophysics Data System (ADS)

Cuba acts as the northwestern boundary of the Caribbean Sea. However it is not part of the Caribbean plate, its geological development is deeply related to the plate history. In fact, its Cretaceous volcanic arc rocks tightly correlate with coeval sections in Hispaniola and Puerto Rico, and the same probably occurs with the ophiolites. The early Palaeogene events in Cuba were also involved in the Caribbean plate history. In general, two principal structural levels can be distinguished in the geological structure of Cuba. The rocks belonging to the upper level (Eocene to Quaternary) are little disturbed and can be referred to as the cover. Below it occurs the great complex of the Cuban orogenic belt, which consists mainly of rocks of Jurassic to Eocene age. In addition, small outcrops of Proterozoic metamorphic rocks also occur in north central Cuba. The Palaeocene-Eocene section contains volcanic arc sequences in SE Cuba and northward thrusted piggy back and foreland basins in central and western Cuba. The Mesozoic rocks lies unconformably below. The contacts between the major Mesozoic elements are always tectonic. With the exception of the rocks of the passive Mesozoic margin of North America in northern Cuba, the remaining units represent tectonostratigraphic terranes extending parallel to the axis of the present main island of Cuba. The northernmost unit is the Mesozoic passive continental margin of North America. It consists of a Jurassic- Cretaceous mainly marine sedimentary sequence now exposed as a thrust and fold belt along the northern edge of the Cuban mainland. The other units are, from north to south: the Northern Ophiolitic Belt, the Volcanic Arc Terrane and the Southern Metamorphic Terranes. The ophiolites and the Cretaceous volcanic arc terranes belong to the Proto-Caribbean plate and were accreted to the palaeomargin during Late Cretaceous and early Palaeogene episodes. Some constrains to Caribbean plate origin and evolution according to data from Cuba: Ophiolites: 1- The age of the rocks of the northern ophiolite belt is Upper Jurassic-Albian. Oceanic lithosphere formation, at least in the "Cuban" Proto-Caribbean, ended in the Albian. Cretaceous volcanic arcs: 2- At least two volcanic arc Cretaceous sections are present in Cuba, separated in several regions by a mainly sedimentary Albian-Cenomanian section. The lower arc is probably of Aptian-Albian age. The Cenomanian (or Turonian?) -Campanian upper arc is calcalkalic and contains abundant sedimentary marine interbeds. 3- Some thin tuff beds are present in the southernmost deep water deposits of the North American palaeomargin in western and central Cuba in the Aptian-Cenomanian. This fact could be explained by a volcanic arc located several hundred km to the south of the NA palaeomargin. 4- Cretaceous volcanism ended during the early Campanian all along Cuba. Sedimentary upper Campanian and Maastrichtian sections rest on top of the older Cretaceous sections. Volcanism is only reassumed in SE Cuba (Turquino volcanic arc) late in the Danian. Southern metamorphic terranes: 5- The southern metamorphic terranes are a main feature in the geology of Cuba. They are continental blocks sharing many stratigraphic features with the NA palaeomargin of western Cuba (Guaniguanico mountains). As the last one area seems related to the Yucatan (Maya) block, some authors consider the metamorphic terranes as fragments of the Maya block that travelled to the west.

Cobiella, J.; Hueneke, H.; Meschede, M.; Sommer, M.



The dynamics of intra-oceanic subduction zones: A direct comparison between fossil petrological evidence (Rio San Juan Complex, Dominican Republic) and numerical simulation  

NASA Astrophysics Data System (ADS)

Dispersed blocks of various types of metamorphic rocks in serpentinite mélanges of the northern Dominican Republic (Hispaniola) provide fossil evidence for the dynamics of the subduction zone channel in the intra-oceanic Caribbean subduction zone system between 120 and 55 Ma. Comprehensive petrological and geochronological data on three exemplary samples of eclogite and blueschist are presented that allow a series of different but interrelated pressure-temperature-time paths to be delineated. Eclogites indicate a low P/T gradient during subduction and record conditions in the nascent stages of the subduction zone. Lu-Hf data yield 103.6 ± 2.7 Ma for peak metamorphic conditions of 23 kbar/750 °C. An anticlockwise P-T path is defined. Other blocks record the continuous cooling of the evolving subduction zone and show typical clockwise P-T-paths. Omphacite blueschists reach maximum P-T-conditions of 17-18 kbar/520 °C at 80.3 ± 1.1 Ma (Rb-Sr age data). The mature subduction zone is typified by jadeite blueschists recording very high ("cold") P/T gradients. A Rb-Sr age of 62.1 ± 1.4 Ma dates peak metamorphic P-T conditions at 16-18 kbar/340-380 °C. The array of P-T-t data allows overall cooling rates of the subduction zone at depths of c. 60 km to be constrained at 9 °C/Ma. Cooling rates and exhumation rates (i.e., vertical component of retrograde trajectories) of the metamorphic blocks are 9-20 °C/Ma and 5-6 mm/a, respectively. The derived P-T-t array is compared with a 2-D numerical subduction-zone model published by Gerya et al. [Gerya, T.V., Stöckhert, B. and Perchuk, A.L., 2002. Exhumation of high-pressure metamorphic rocks in a subduction channel: a numerical simulation. Tectonics 142, 6-1-6-19.; 45° slab dip, 40 Ma lithosphere age, convergence rates of 10-40 mm/a], which incorporates weakening of lithospheric mantle of the hanging wall by fluids emanating from the downgoing slab, resulting in an increasingly more funnel-shaped subduction channel system with time. The numerically derived array of simulated P-T-t paths as well as the calculated rates of exhumation and cooling agree well with the P-T-t data derived from the metamorphic blocks of the Rio San Juan serpentinite mélanges when convergence rates of 15 to 25 mm/a are chosen. This value is also in accord with available paleogeographic reconstructions calling for a long-term average of 22 mm/a of orthogonal convergence. On the basis of the comparison, the onset of subduction in the Rio San Juan segment of the Caribbean Great Arc can be constrained to approximately 120 Ma. This segment was thus obviously active for more than 65 Ma. An orthogonal convergence rate of 15-25 mm/a requires that a minimum amount of 975-1625 km of oceanic crust must have been subducted. Both petrological/geochronological data and numerical simulation underscore the broad spectrum of different P-T-t paths and peak conditions recorded by material subducted at different periods of time as the subduction zone evolved and matured.

Krebs, M.; Maresch, W. V.; Schertl, H.-P.; Münker, C.; Baumann, A.; Draper, G.; Idleman, B.; Trapp, E.



Geochemistry of jadeitites and jadeite-lawsonite rocks in a serpentinite mélange (Rio San Juan Complex, northern Dominican Republic): Constraints on fluid composition in a subduction channel environment  

NASA Astrophysics Data System (ADS)

Jadeitites are excellent rock types for obtaining information on fluid composition in subduction zones. Recent studies indicate that many jadeitites appear to have formed by direct precipitation from a fluid [1]. In almost all localities worldwide (see e.g. Harlow and Sorensen, 2005) jadeitites are found either as allochthonous blocks or as veins and lenses directly within the serpentinite country rock of serpentinite mélanges. In the Rio San Juan Complex on the other hand jadeitite also frequently occurs as veins (cm to some dm in thickness) within lawsonite-blueschist blocks [2,3,4] entrained in the serpentinite mélange. The mélange of the Rio San Juan Complex also contains blocks (m to 10m scale) of different metamorphic grade and lithology (eclogites, blueschists, orthogneisses and very low grade rocks) showing contrasting but interrelated P-T-t paths. The consistency of such interrelated P-T-t paths with those obtained by numerical models led Krebs et al. [5] to interpret the mélange of the Rio San Juan Complex as a former subduction channel. So far, two types of jadeitite have been found in the blueschist blocks: either as discordant veins cutting the foliation, or as concordant layers. In some cases the jadeitites contain large amounts of lawsonite and should then better be called jadeite-lawsonite rocks. The latter rock type may form a network of thin (< 1cm) veinlets that are folded. In both jadeitite and jadeite-lawsonite rocks XJd in clinopyroxene ranges between 0.80 and 0.99. The contact between vein and host rock is very sharp and petrographically no sign of a depletion zone near the vein can be recognized, indicating that the infiltrating fluid originated from an external source and was not released from the adjoining host rock. A mineralogical center-to-rim zonation has been identified in the jadeitite veins. Near the contact to the blueschist, lawsonite is the dominant mineral phase and towards the center the amount of jadeite increases. Major and trace element concentrations also change from centers to rims. Ca/Na varies from 0.75-0.77 in the center to 1.03-1.29 in the rim; the rims are enriched in Rb, Ba, Pb, Eu and have slightly higher REE concentrations than the centers. This may be explained by the lower solubility of lawsonite compared to that of jadeite [6], causing lawsonite to crystallize first during precipitation. Lawsonite crystallization leads to a decrease of the Ca/Na ratio in the fluid. When the Ca/Na ratio becomes low enough jadeite starts to crystallize. Based on chemical data, jadeitites and jadeite-lawsonite rocks can be subdivided into two groups. The chondrite-normalised REE pattern of the first group shows decreasing normalized values from LREE (40-10 times) towards HREE (8-1 times). The second group has a U-shaped pattern with a strong positive Eu (5 times) anomaly. Even though no depletion zone in the adjoining host rock of the jadeitite is petrographically visible, there are lower REE concentrations in blueschists directly adjacent to the veins as compared to homogeneous blueschists without any veins. This clearly indicates some fluid-rock interaction during formation of the veins. References 1) Harlow G.E., Sorensen S.S. (2005) Jade (nephrite and jadeitite) and serpentinite: Metasomatic connections. International Geology Review 47:113-146. 2) Schertl, H.-P., Maresch, W.V., Krebs, M., Draper, G. (2007) The Rio San Juan serpentinite complex and its jadeitites (Dominican Republic). In: Martens U., García-Casco A. (eds) High-pressure belts of Central Guatemala: the Motagua suture and the Chuacús Complex. IGCP 546 Special Contribution, 1. 3) Schertl, H.-P., Krebs, M., Maresch, W.V., Draper, G. (2007) Jadeitite from Hispaniola: a link between Guatemala and Antigua? 20th Colloquium on Latin American Earth Sciences, Kiel, Germany, Abstract Volume, 167-168 4) Baese, R., Schertl, H.-P., Maresch, W.V. (2007) Mineralogy and petrology of Hispaniolan jadeitites: first results. In: Martens U., García-Casco A. (eds) High-pressure belts of Central Guatemala: the Motagua suture and the

Baese, Rauno; Maresch, Walter V.; Schenk, Volker; Schertl, Hans-Peter