scholarly journals On the interaction of the North Andes plate with the Caribbean and South American plates in northwestern South America from GPS geodesy and seismic data

2018 ◽  
Vol 214 (3) ◽  
pp. 1986-2001 ◽  
Author(s):  
Omar J Pérez ◽  
Steven G Wesnousky ◽  
Roberto De La Rosa ◽  
Julio Márquez ◽  
Redescal Uzcátegui ◽  
...  
Author(s):  
Cameron Jones

While it is certainly true that more academic studies have focused on the North American missions, in terms of their historical impact South American missions were just as important to the frontiers of Spain and Portugal’s American empires. The massive size alone of the frontier region, stretching from the upper reaches of the Amazon basin to the headwaters of the Paraná as well as stretching across the lower Southern Cone, meant numerous missionary enterprises emerged in an attempt to evangelize the peoples who inhabited these regions. While small handfuls of Dominicans, Mercedarians, and Augustinians would engage in such efforts, most missions were established by the Jesuits or Franciscans. Certainly, for the Jesuits, or the Society of Jesus as they are properly known, American missions represented an extension of the Counter-Reformation for which they were created. Starting in the mid-16th century, this relatively new organization, founded in 1534, began in earnest to “reduce” the Indigenous peoples into their missions. These activities, however, abruptly ended when the Jesuits were expelled from both the Portuguese and Spanish empires in 1759 and 1767 respectfully. The much older Franciscan order had extensive experience in popular missions in Europe and was one of the first orders of regular clergy in the Americas. Franciscans, like the Jesuits, engaged in evangelizing activities throughout both North and South America from the colonial period to the present. The expulsion of the Jesuits, however, pushed them further to the forefront of missionizing efforts in the late colonial period. This acceleration of Franciscan missionary activity was aided by the establishment of the Apostolic Institute in 1682. The Institute created a pipeline of missionaries from Spain to come directly to frontier areas with funding from the crown. While this aided missionary efforts throughout South America, particularly in areas abandoned by the Jesuits, it embroiled the missionaries in the politics of the Bourbon reforms and their obsession with limited clerical power. Ultimately, while missionizing efforts continued into the Republican period, their association with the Spanish and Portuguese crowns led to widespread suppression and secularization following independence. The historiographical divide in the field tends to lie between usually older, Eurocentric histories by scholar-clerics which focus on the missionaries themselves, and newer studies carried out by more secular professional historians that examine how Indigenous populations were affected by the inherent imperialism of the missions, though exceptions abound.


1951 ◽  
Vol 16 (4) ◽  
pp. 354-355
Author(s):  
Gordon R. Willey

In a recent note Baerreis (1950) has given critical amplification to the question of possible cultural relations between the southeastern United States Archaic and the archaeologically known culture, or cultures, of the lower Parana River, Argentina. A paper of my own (Willey, 1949), on which Baerreis centers his discussion, focused attention on the Caribbean area and the north of the South American continent, giving only brief mention to interesting southeastern resemblances which may be found along the Parana and in the Sambaquis of southern Brazil. I agree that Baerreis has strengthened the case for cultural connections over and beyond the casual comments which I or others have offered.


2020 ◽  
Author(s):  
Berrocoso Manuel ◽  
Del Valle Arroyo Pablo Emilio ◽  
Colorado Jaramillo David Julián ◽  
Gárate Jorge ◽  
Fernández-Ros Alberto ◽  
...  

<p>The northwest of South America is conformed by the territories of Ecuador, Colombia and Venezuela. Great part of these territories make up the Northern Andes Block (BAN). The tectonic and volcanic activity in the northwest of South America is directly related to the interaction of the South American plate, and the Nazca and Caribbean plates, with the Maracaibo and Panama-Chocó micro plates. The high seismic activity and the high magnitude of the recorded earthquakes make any study necessary to define this complex geodynamic region more precisely. This work presents the velocity models obtained through GNSS-GPS observations obtained in public continuous monitoring stations in the region. The observations of the Magna-eco network (Agustín Codazzi Geographic Institute) are integrated with models already obtained by other authors from the observations of the GEORED network (Colombian Geological Service). The observations have been processed using Bernese software v.52 using the PPP technique; obtaining topocentric time series. To obtain the speeds, a process of filtering and adjustment of the topocentric series has been carried out. Based on this velocity model, regional structures have been defined within the Northern Andes Block through a differentiation process based on the corresponding speeds of the South American, Nazca and Caribbean tectonic plates. Local geodynamic structures within the BAN itself have been established through cluster analysis based on both the direction and the magnitude of each of the vectors obtained. Finally, these structures have been correlated with the most significant geodynamic elements (fractures, faults, subduction processes, etc.) and with the associated seismic activity.</p>


2005 ◽  
Vol 18 (23) ◽  
pp. 4993-5010 ◽  
Author(s):  
Samson M. Hagos ◽  
Kerry H. Cook

Abstract Previous studies show that the climatological precipitation over South America, particularly the Nordeste region, is influenced by the presence of the African continent. Here the influence of African topography and surface wetness on the Atlantic marine ITCZ (AMI) and South American precipitation are investigated. Cross-equatorial flow over the Atlantic Ocean introduced by north–south asymmetry in surface conditions over Africa shifts the AMI in the direction of the flow. African topography, for example, introduces an anomalous high over the southern Atlantic Ocean and a low to the north. This results in a northward migration of the AMI and dry conditions over the Nordeste region. The implications of this process on variability are then studied by analyzing the response of the AMI to soil moisture anomalies over tropical Africa. Northerly flow induced by equatorially asymmetric perturbations in soil moisture over northern tropical Africa shifts the AMI southward, increasing the climatological precipitation over northeastern South America. Flow associated with an equatorially symmetric perturbation in soil moisture, however, has a very weak cross-equatorial component and very weak influence on the AMI and South American precipitation. The sensitivity of the AMI to soil moisture perturbations over certain regions of Africa can possibly improve the skill of prediction.


Tectonics ◽  
2015 ◽  
Vol 34 (6) ◽  
pp. 1181-1194 ◽  
Author(s):  
John C. Weber ◽  
Halldor Geirsson ◽  
Joan L. Latchman ◽  
Kenton Shaw ◽  
Peter La Femina ◽  
...  

2010 ◽  
Vol 23 (6) ◽  
pp. 1477-1494 ◽  
Author(s):  
Kerry H. Cook ◽  
Edward K. Vizy

Abstract The easterly Caribbean low-level jet (CLLJ) is a prominent climate feature over the Intra-America Seas, and it is associated with much of the water vapor transport from the tropical Atlantic into the Caribbean Basin. In this study, the North American Regional Reanalysis (NARR) is analyzed to improve the understanding of the dynamics of the CLLJ and its relationship to regional rainfall variations. Horizontal momentum balances are examined to understand how jet variations on both diurnal and seasonal time scales are controlled. The jet is geostrophic to the first order. Its previously documented semidiurnal cycle (with minima at about 0400 and 1600 LT) is caused by semidiurnal cycling of the meridional geopotential height gradient in association with changes in the westward extension of the North Atlantic subtropical high (NASH). A diurnal cycle is superimposed, associated with a meridional land–sea breeze (solenoidal circulation) onto the north coast of South America, so that the weakest jet velocities occur at 1600 LT. The CLLJ is present throughout the year, and it is known to vary in strength semiannually. Peak magnitudes in July are related to the seasonal cycle of the NASH, and a second maximum in February is caused by heating over northern South America. From May through September, zonal geopotential gradients associated with summer heating over Central America and Mexico induce meridional flow. The CLLJ splits into two branches, including a southerly branch that connects with the Great Plains low-level jet (GPLLJ) bringing moisture into the central United States. During the rest of the year, the flow remains essentially zonal across the Caribbean Basin and into the Pacific. A strong (weak) CLLJ is associated with reduced (enhanced) rainfall over the Caribbean Sea throughout the year in the NARR. The relationship with precipitation over land depends on the season. Despite the fact that the southerly branch of the CLLJ feeds into the meridional GPLLJ in May through September, variations in the CLLJ strength during these months do not impact U.S. precipitation, because the CLLJ strength is varying in response to regional-scale forcing and not to changes in the large-scale circulation. During the cool season, there are statistically significant correlations between the CLLJ index and rainfall over the United States. When the CLLJ is strong, there is anomalous northward moisture transport across the Gulf of Mexico into the central United States and pronounced rainfall increases over Louisiana and Texas. A weak jet is associated with anomalous westerly flow across the southern Caribbean region and significantly reduced rainfall over the south-central United States. No connection between the intensity of the CLLJ and drought over the central United States is found. There are only three drought summers in the NARR period (1980, 1988, and 2006), and the CLLJ was extremely weak in 1988 but not in 1980 or 2006.


Author(s):  
Luís Fernando Pita Gondim ◽  
Rodrigo Martins Soares ◽  
Gastón Moré ◽  
Rogério Fernando de Jesus ◽  
Horwald Alexander Bedoya Llano

Abstract Protozoan parasites of the genus Sarcocystis are obligatory heteroxenous cyst-forming coccidia that infect a wide variety of animals and encompass approximately 200 described species. At least four Sarcocystis spp. (S. falcatula, S. neurona, S. lindsayi and S. speeri) use opossums (Didelphis spp.) as definitive hosts, and two of them, S. neurona and S. falcatula, are known to cause disease in horses and birds, respectively. Opossums are restricted to the Americas, but their distribution in the Americas is heterogeneous. Five Didelphis spp. are distributed in South America (D. aurita, D. albiventris, D. marsupialis, D. imperfecta and D. pernigra) whereas just one opossum species (D. virginiana) is found in North America. Studies conducted in the last decades show that Sarcocystis spp., derived from South American Didelphis spp., have biological and genetic differences in relation to Sarcocystis spp. shed by the North American opossum D. virginiana. The aim of this review was to address the peculiar scenario of Sarcocystis species shed by South American opossums, with a special focus on diagnosis, epidemiology, and animal infections, as well as the genetic characteristics of these parasites.


Zootaxa ◽  
2012 ◽  
Vol 3596 (1) ◽  
pp. 1 ◽  
Author(s):  
HARLAN K. DEAN

A list of all known polychaete species reported in the primary literature is presented for the Caribbean Sea. The most spe-cies-rich polychaete faunas are those of Cuba in the North Caribbean ecoregion and Trinidad-Tobago and Colombia in theSouth Caribbean ecoregion while the ecoregion with the greatest number of species is the Greater Antilles. While part ofthe explanation for these higher diversity areas may be due to collection effort, these areas may also be higher in speciesnumber as a result of being ecotones between the Gulf of Mexico in the north and the northern South American region tothe south. The most species-rich families are the Syllidae, Eunicidae, Nereididae, Polynoidae, Sabellidae, Serpulidae, Ter-ebellidae, and Spionidae. A brief discussion of the history of polychaete research identified many of the more importantworkers in the characterization of the polychaete fauna of the region. An analysis of the species-record accumulation curvefor polychaetes indicated that this fauna has not yet been fully characterized. One portion of the polychaete fauna identified as being especially poorly known is that from the deep-water areas of the Caribbean.


2021 ◽  
pp. 1035-1057
Author(s):  
Pekka Hämäläinen

This chapter re-examines the powerful nomadic-equestrian societies in the North and South American grasslands and makes the case for a distinctive imperial formation, the kinetic empire. Kinetic empires were shape-shifting, action-based regimes that turned mobility into an imperial strategy and revolved around mobile activities: long-distance raiding, seasonal expansions, transnational diplomatic missions, semi-permanent trade fairs, recurring political assemblies, and control over shifting nodes. Their governing systems were light and flexible, and they rose and stayed in power by capitalizing on their superior capacity to access and connect political and economic centers around them. The Comanche and Lakota Indians created the Western Hemisphere’s most prominent examples of kinetic empires in the North American Great Plains. In South America the Araucanians frustrated European colonizing efforts, commanded a large and expanding territory, and pulled other Native groups on their orbit, but lacked the Comanches’ and Lakotas’ strong collective identities and political unity.


2020 ◽  
Vol 45 (4) ◽  
pp. 913-920
Author(s):  
Nidia Mendoza-Díaz ◽  
Marina Díaz ◽  
Patricia Brussa ◽  
Fabián Muñoz ◽  
José M. Bonifacino ◽  
...  

Abstract—Antiphytum charruasorum, a new endemic species from western Uruguay, is described. This is the only South American species in the genus with white corolla and an infra-medial cicatrix on the ventral face of the eremocarp, both features shared with the North American species of Antiphytum, in sharp contrast with the blue corolla and the basal cicatrix at the end of a stipe-like prolongation that characterizes all South American species in the genus. Antiphytum charruasorum increases the diversity of the genus in South America, as well as the endemism and distribution range into Uruguay. Moreover, this new species adds novel features in Antiphytum such as the irregularly dichasial inflorescences, the hirsute faucal appendages, the eremocarps with a tissue plug from the gynobase, and the habitat where the species has been reported.


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