Northern Part Of South America Research Articles

Provenance of the late Jurassic to Cenomanian sedimentary succession of the Araripe Basin (NE Brazil) and implication for the geodynamic evolution of Western Gondwana

The separation of Gondwana was controlled by preexisting Proterozoic structures and by the development of rift aborted basins, of which the Araripe Basin (NE Brazil) is one of the best examples. Previous studies have focused on the presence and provenance of Aptian–Albian shallow-marine incursions in the Araripe Basin but to date, little attention has been given to its paleodrainage evolution during sedimentation stages. Understanding the paleodrainage evolution is crucial for determining sediment sources and how topographic changes relate to the geodynamic development of the northern part of South America during the fragmentation of Gondwana, and this study investigates the provenance of Mesozoic rift and post-rift sedimentary rocks in the Araripe Basin using a multi-proxy dataset comprising major and trace element concentrations, Sm–Nd isotopic composition, and detrital zircon U–Pb ages. The low Eu/Eu* ratios (0.3–0.9) and high Th/Sc ratios (>0.64) in the most of analyzed samples suggest a felsic and silicic source. The εNd(0) values (−12.3 to −23.7) and TDM ages (1.68 to 2.55 Ga) of analyzed samples suggest overall ancient crustal sources. The presence of oval and elongated zircon grains suggests a major contribution of first-cycle transport sediments. The presence of 2.3–1.8 Ga and 0.63–0.58 Ga U–Pb zircon ages further indicates the dominant contribution of the Borborema Province influenced by the Brasiliano cycle (650–520 Ma). The low contribution of Tonian (∼940 Ma) zircons to the U–Pb zircon age distribution of the rift-beginning stage sample associated with published paleocurrent direction suggests sources located in the northern and northwestern terranes of the Borborema Province. The increase of Tonian (0.9–1.0 Ga) zircon grains during the rift stage suggests a provenance change with a dominant source in the eastern terranes during the rift stage. During the post-rift I stage, the decrease of 1.2–0.72 Ga zircon ages suggests a change in the source areas, with the paleodrainage coming from northern Borborema Province, similar to that of the rift-beginning stage. The samples of the post-rift II stage exhibit dominant contributions of Paleoproterozoic and Neoproterozoic U–Pb ages related to the Albian to Cenomanian uplift of the Borborema plateau during the opening of Equatorial Atlantic Ocean. Together with previous published studies, these findings highlight the significant role played by the post-rift continental uplift to the paleodrainage of the northern part of South America.

A contribution to the knowledge of Cretaceous to Neogene Palynology in the Colombian Caribbean.

The palynological study of a composite section of 14 cores drilled from the Sinu-San Jacinto Basin in the Colombian Caribbean (NW South America) provides for the first time a Cenozoic palynostratigraphic zonation scheme for this region. In addition, the study of calcareous nannofossils and planktonic foraminifera allowed an independent calibration of the palynomorph assemblages to the international chronostratigraphic chart. The palynological results were compared with other studies for the northern part of South America and Colombia. Twelve Late Paleocene-Pliocene palynological zones are proposed for the Caribbean, some of which differ from those proposed for the Llanos and Llanos Foothills basins. A Paleocene palynological assemblage is reported for this part of the basin. Variations in the biostratigraphic ranges of some palynomorphs and new species with stratigraphic value are described. High diversity and abundance of dinoflagellate cysts in some stratigraphic intervals require more detailed study. Evidence of reworking in some stratigraphic intervals (e.g., Cretaceous and Oligocene in Miocene sediments), makes it necessary to be careful about the last appearance record of microfossils in exploration and geologic mapping.

Integrated coastal zone management in Colombia: 25 years of implementing an environmental planning policy

Integrated Coastal Zone Management (ICZM) emerged as a strategy ecosystem approach for management seas and coasts, responding to international agreements such as the Convention on Biological Diversity with the Jakarta Mandate and the Convention on Climate Change. Colombia, located in the northern part of South America with coasts on the Pacific Ocean and the Caribbean Sea, has institutionally adopted the ICZM for 25 years, establishing definitions, procedures, and instruments. The purpose of this work is to analyse the implementation of the ICZM in Colombia, as well as to identify future actions, considering the lessons learned. A participatory diagnosis was carried out using the Delfi method and an analysis of ICZM progress indicators. It was found that the implementation of the policy has been carried out through applied scientific research in order to build the methodology known (COLMIZC), which has become a reference for Latin America and is widely discussed in comparison to regional advances. The ICZM process has made it possible to consolidate a public policy, giving it relevance within the environmental agenda and the country's development plans. However, the creation of other political instruments that have not been well articulated with environmental policy has led to uncoordinated actions. Colombia has advanced conceptually and methodologically in the configuration of a political and regulatory framework. It is important to strengthen capacities in institutions and communities to provide local interventions with national and global impact. It is a priority to coordinate with the territorial authorities and influence sectoral planning.

Non-linear modes of global sea surface temperature variability and their relationships with global precipitation and temperature

Sea surface temperature (SST) modes are comprised of variability that arises from inherently nonlinear processes. Historically, a limitation arises from applying linear statistics to define these modes. Accurate depiction of the complex, non-linear nature of SST modes of variability necessitates the specification of a model capable of producing nonlinear patterns. In this study, we apply an artificial neural network algorithm integrated with autoencoders to analyze the seasonal non-linear global SST modes allowing for improved characterization of the modes and their large-scale temperature and precipitation teleconnections. Our results show that during boreal summer, SST cooling over the central to eastern tropical Pacific co-occurs with the Arctic amplification. In recent decades, the negative SST trend in the central to eastern tropical Pacific, combined with the positive trend in the western tropical Pacific is linked to an increase in the amplitude of SST modes associated with the Arctic warming, resulting in warmer temperatures over large portions of the global land, particularly over Greenland. In boreal winter, El Niño Southern Oscillation (ENSO) is the prominent global SST mode. The distinct spatiotemporal patterns of ENSO modes are associated with unique effects on regional land temperature and precipitation. The central Pacific El Niño is more associated with the combination of warm and dry conditions over Western Australia, and the northern part of South America. Conversely, the central to eastern El Niño is more associated with the combination of warm and dry conditions over parts of Southern Africa, and the northern part of South America. The spatiotemporal patterns and trends in the amplitude of the analyzed non-linear global SST modes alongside their regional influences on temperature and precipitation are discussed. The broader impact of this study is on the potential of neural networks in effectively delineating non-linear global SST modes and their associations with regional climates.

New species and record of Diplosmittia Sther, 1981 (Diptera: Chironomidae, Orthocladiinae) from Brazil and Colombia.

Chironomidae is a diverse Diptera family found worldwide. The genus Diplosmittia Sther, 1981, currently with 11 valid species, has been found exclusively in the New World, mainly in the Caribbean and in the northern parts of South America; only three species are recorded from Brazil and none from Colombia so far. In the present study a new species of Diplosmittia is described and illustrated based on material collected in northeastern Brazil. It appears to be most closely related to Diplosmittia beluina Andersen, 1996, but can be distinguished by morphological differences in the virga and gonostylus. Diplosmittia harrisoni Sther, 1981 is documented for the first time from Colombia, and D. carinata Sther, 1985 is formally placed as a junior synonym of D. harrisoni. In addition, an update identification key to all known species of the genus has been provide.

Hydro-climatic variability anomalies over south America with El Nio-southern oscillation: Precipitation Anomalies and their socio-economic impact in the Colombia country

This paper reviews climatic anomalies in Colombia, and South America, primarily based on CMIP6 model with data from the World Bank Group and the Climatic Data Store API under the emission scenarios SSP1-2.6 and SSP5-8.5. Due to the processing of atmospheric dynamics, ENSO directly affects the northern part of South America and indirectly affects subtropical South America. El Nio years are distinguished by higher incidence of dry weather extremes, and during neutral or La Nia years are likelier to experience wet weather extremes. Overall, western part of Colombia is colder than the southeast since it incorporates a portion of the Andes Mountains. Each of the four seasons has rising temperatures ranging from 2.2 to 5.2 , with the nation's southern, eastern, and northern regions suffering the highest increases. The west of Colombia experiences more rain throughout the year than the rest of the country, which has the highest precipitation in the spring and summer. Droughts and reduced water supply carried on by rising temperatures could damage infrastructure, damage the environment, loss of revenue, and severe societal effects when combined with flooding brought on by higher precipitation and rainfall anomalies.

Distribution of the northern pampas cat, Leopardus garleppi, in northern South America, confirmation of its presence in Colombia and genetic analysis of a controversial record from the country

Abstract The common name of pampas cat includes a complex of small Neotropical felid species found in various habitats of South America. Recently several species of this complex were proposed, but there are few records in the northernmost distribution of the continent, and reports of the pampas cat’s presence in Colombia have been ambiguous. Current northern limits of Leopardus garleppi are limited to the Andes of Ecuador. Here we present the northernmost record of the species, validating its presence in Colombia and review previous controversial records from the country. The new record is based on a road-killed specimen in a dry tropical forest ecosystem in the municipality of Mercaderes, Department of Cauca. Our morphological and genetic comparisons also shown that a previous record from Colombia supported by a single skin recently used to described a new species named Leopardus narinensis belong to Leopardus tigrinus. With the information compiled from new localities in Colombia and Ecuador, the known distribution range for L. garleppi is increased towards the northern part of South America into areas of Tropical Dry Forest. The distribution now includes 14 ecoregions from Colombia to Bolivia, and four in Colombia (Eastern Cordillera real montane forests, Northwestern Andean montane forests, Northern Andean paramo, and the Patía Valley dry forests), which correspond to similar ecosystems inhabited by the species in other Andean landscapes. The potential distribution hypothesis showed that the species has high suitability in large areas of southwestern Colombia (Nariño). With the recording of L. garleppi in Colombia, the number of extant felid species in the country has increased to seven.

Electrophysiological detection of visible wavelengths of artificial lights inducing take-off in adults of Rhodnius prolixus (Hemiptera: Triatominae)

Rhodnius prolixus is the most important vector of Trypanosoma cruzi in the northern part of South America. The compound eyes in adults of R. prolixus are involved in the nocturnal flight dispersion from sylvatic environments into human dwellings. During this behavior, the artificial lights play an important role in attracting R. prolixus; however, it is still not clear whether the compound eyes of this species use different visible wavelengths as a cue during active dispersion. We applied electrophysiological (electroretinography or ERG) and behavioral (take-off) experiments in a controlled laboratory setting to determine the spectral sensitivity of the compound eyes and the attraction of R. prolixus adults to discrete visible wavelengths. For the ERG experiments, flashes of 300 ms at wavelengths ranging between 350 and 700 nm at a constant intensity of 3.4 µW/cm2 were tested after adaptation to darkness and to blue and yellow lights. For the behavioral experiments, the adults were exposed to nine visible wavelengths at three different intensities, and their direction of take-off in an experimental arena was established with circular statistics. The ERG results showed peaks of spectral sensitivity at 470-490 nm and 520-550 nm in adults, while behavioral experiments showed attractions to blue, green and red lights, depending on the intensity of the light stimuli. The electrophysiological and behavioral results confirm that R. prolixus adults can detect certain wavelengths in the visible spectrum of light and be attracted to them during take-off.

Atmospheric Contributions to Global Ocean Tides for Satellite Gravimetry

AbstractTo mitigate temporal aliasing effects in monthly mean global gravity fields from the GRACE and GRACE‐FO satellite tandem missions, both tidal and non‐tidal background models describing high‐frequency mass variability in atmosphere and oceans are needed. To quantify tides in the atmosphere, we exploit the higher spatial (31 km) and temporal (1 hr) resolution provided by the latest atmospheric ECMWF reanalysis, ERA5. The oceanic response to atmospheric tides is subsequently modeled with the general ocean circulation model MPIOM (in a recently revised TP10L40 configuration that includes the feedback of self‐attraction and loading to the momentum equations and has an improved bathymetry around Antarctica) as well as the shallow water model TiME (employing a much higher spatial resolution and more elaborate tidal dissipation than MPIOM). Both ocean models consider jointly the effects of atmospheric pressure variations and surface wind stress. We present the characteristics of 16 waves beating at frequencies in the 1–6 cpd band and find that TiME typically outperforms the corresponding results from MPIOM and also FES2014b as measured from comparisons with tide gauge data. Moreover, we note improvements in GRACE‐FO laser ranging interferometer range‐acceleration pre‐fit residuals when employing the ocean tide solutions from TiME, in particular, for the S1 spectral line with most notable improvements around Australia, India, and the northern part of South America.

José Celestino Mutis and the gestation of ichthyology in the Viceroyalty of New Granada

José Celestino Mutis, mostly known for his contributions in the botanical field, however; made significant, if little known, scientific additions in fields from mathematics to zoology. In this paper, I present to the public, for the first time, Mutis’ work on ichthyology in the Viceroyalty of New Granada, the colonial Spanish denomination for the northern part of South America that includes the present-day countries of Panama, Colombia, Venezuela, and Ecuador, work that, as Linnaeus himself stated, will immortalize Mutis for future generations.

Apologetics and Antiquity: Book of Mormon Reception, 1830–1844

Apologetics and Antiquity: Book of Mormon Reception, 1830–1844

Revealing migration schedule and potential breeding grounds of Lined Seedeaters using citizen science data

ABSTRACT The Lined Seedeater (Sporophila lineola) is a small intra-tropical migrant songbird. However, little is known about its breeding and wintering grounds, or migratory habits. To investigate potentially distinct breeding populations and the migratory schedule of Lined Seedeaters we analysed its spatial and temporal distribution using published breeding records, museum vouchers, and data from citizen science projects (eBird and WikiAves). Our findings suggest that there are three main breeding areas: northern Argentina and north-western Paraguay, south-eastern Brazil, and north-eastern Brazil, and that the breeding season seems to be restricted to November through May, with slight differences in timing among these three areas. The species winters in the northern part of South America (mostly in grassland areas) and maybe also in the Amazonia. Moreover, rainfall predicts the latitudinal and longitudinal movements of Lined Seedeaters, with the migratory movements associated with an increase in rainfall. Taken together, these results provide a first comprehensive overview on the migration of Lined Seedeater, calling for further empirical field studies. Understanding intra-tropical migratory patterns is paramount to comprehend the potential impacts of environmental change in tropical ecosystems.

Crustal structure and tectonic implications of the southernmost Merida Andes, Venezuela, from wide-angle seismic data analysis

The crustal structure of the Merida Andes in southwestern Venezuela is crucial to our understanding of both, the complex regional geodynamics of the northern part of South America, as well as the development of the hydrocarbon basins located along its flanks. Symmetric and asymmetric models of the Merida Andes have been proposed based on geological and geophysical (principally gravimetric) surveys, without counting detailed structures from wide-angle seismic. This work examines the crustal structure of the southwestern part of the Merida Andes in Venezuela using controlled seismic sources along a 500 km wide-angle seismic profile (named ANDES SUR). Forward modeling is carried out to obtain a layer-based, P-wave, crustal velocity model. An alternative velocity model is obtained by applying a first arrival tomography for the upper 20 km depth, and a joint PmP and Pn inversion for the deeper crust. Important lateral P-wave velocity variations and low-velocity zones (LVZ) are observed within the upper crust. To the northwest, these lateral velocity variations are probably related to the deformation zones of Icotea and Tarra Faults, and the southeast to the Mantecal and Apure grabens. The integration of seismological data to the profile provides some clues about a possible slow-shear movement between the upper and the lower crust (brittle-ductile transition zone) at the NW end of the profile, as well as the possible northwestward incipient subduction of the South American Plate beneath the Maracaibo Triangle Block. We interpret the Boconó Fault's main trace as a take-off surface detaching from the interface between the upper and lower crust and dipping to the SE. A slight NW displaced crustal root of the Merida Andes is observed in all models, being the root ∼150 km wide with an approximately 9 km downward deflection (from ∼46 to 55 km depth) of the Moho. The crustal structure along the profile ANDES SUR, together with the observations along two profiles located further north, provide information about the tectonic implication along the strike of the Merida Andes, favoring an asymmetric model with possible NW directed South American lower crust and upper mantle underthrusting or incipient subduction beneath the Maracaibo Triangle Block beneath the center of the Merida Andes.

A New Genus of Leafhoppers, Zanelopona (Hemiptera: Cicadellidae: Gyponinae) and 20 New Species from South America

A new genus, Zanelopona, is described that is closely related to Hecalapona DeLong and Freytag. Included in the genus are four species previously described in either Hecalapona or Gypona. They are Zanelopona summita (DeLong and Kolbe).new combination, Z. supina (DeLong and Freytag) new combination, Z. antlerita (DeLong and Kolbe) new combination, and Z. huella (DeLong and Freytag) new combination; and twenty new species as follows; Z. calcara, Z. campana, Z. labella, Z. liberata, Z. limba, Z. marea, Z. proceta, and Z. prodigiosa from Colombia; Z. quadrata from Colombia and Ecuador; Z. dilata, and Z. lacerta from Ecuador; Z. doleta, Z. incisa, Z. megalota, and Z. torula from Brazil; Z. anomala, Z. dasida, and Z. juba from Peru; Z. incita from French Guiana; and Z. intensa from Venezula . All species of this new genus are from the northern part of South America down to Peru.

Interhemispheric asymmetry of climate change projections of boreal winter surface winds in CanESM5 large ensemble simulations

A recent study of global wind power using an ensemble of ten CMIP5 climate simulations indicated an interhemispheric asymmetry of wind power changes over the twenty-first century, featured by power decreases across the Northern Hemisphere mid-latitudes and increases across the tropics and subtropics of the Southern Hemisphere. Here we analyze future projections of surface mean and extreme winds by means of a single-model initial-condition 50-member ensemble of climate simulations generated with CanESM5, the Canadian model participated in CMIP6. We analyze the ensemble mean and spread of boreal winter mean and extreme wind trends over the next half-century (2021–2070) and explore the contribution of internal climate variability to these trends. Surface wind speed is projected to mostly decrease in northern mid-low latitudes and southern mid-latitudes and increase in northern high latitudes and southern tropical and subtropical regions, with considerable regional variations. Large ensemble spreads are apparent, especially with remarkable differences over northern parts of South America and northern Russia. The interhemispheric asymmetry of wind projections is found in most ensemble members, and can be related to large-scale changes in surface temperature and atmospheric circulation. The extreme wind has similar structure of future projections, whereas its reductions tend to be more consistent over northern mid-latitudes. The projected mean and extreme wind changes are attributed to changes in both externally anthropogenic forced and internal climate variability generated components. The spread in wind projections is partially due to large-scale atmospheric circulation variability.

Genesis of Easterly Waves over the Tropical Eastern Pacific and the Intra-Americas Sea

AbstractThis paper explores a new mechanism for in situ genesis of easterly waves (EWs) over the tropical eastern Pacific Ocean (EPAC). Using an idealized primitive equation model, it is shown that EWs can be triggered by finite-amplitude transient heating close to the midlevel jet at about 15°N over the EPAC and intra-Americas sea region. The atmospheric response to heating initiates EWs downstream, showing an EW structure within 4 days, with a wavelength and propagation speed of about 2000 km and 4.6 m s−1, respectively, resembling EWs described in the literature. The most sensitive location for EW initiation from finite-amplitude transient heating is located over the northern part of South America and extends to the EPAC. The closer the heating is to the jet, the bigger the response is. A stratiform heating profile is the most efficient at triggering EPAC EWs. Comparisons of simulated EWs over the EPAC and West Africa reveal similar structures but with a shorter wavelength and much weaker amplitudes over the EPAC. EPAC EWs are dominated by horizontal tilts against the shear on the equatorial side of the jet, consistent with barotropic growth, with weaker low-level amplitudes relative to those seen over West Africa. These differences arise from differences in the mean state EPAC having a shorter and weaker midlevel jet with less baroclinicity.

Potential distribution of Amblyomma mixtum (Koch, 1844) in climate change scenarios in the Americas

Amblyomma mixtum is a Neotropical generalist tick of medical and veterinary importance which is widely distributed from United States of America to Ecuador. The aim of this study was to evaluate changes in the geographic projections of the ecological niche models of A. mixtum in climate change scenarios in America. We constructed a database of published scientific publications, personal collections, personal communications, and online databases. Ecological niche modelling was performed with 15 Bioclimatic variables using kuenm in R and was projected to three time periods (Last Glacial Maximum, Current and 2050) for America. Our model indicated a wide distribution for A. mixtum, with higher probability of occurrence along the Gulf of Mexico and occurring in a lesser proportion in the Pacific states, Central America, and the northern part of South America. The areas of new invasion are located mainly on the border of Mexico with Guatemala and Belize, some regions of Central America and Colombia. We conclude that the ecological niche modelling are effective tools to infer the potential distribution of A. mixtum in America, in addition to helping to propose future measures of epidemiological control and surveillance in the new potential areas of invasion.

Dust from the Sahara to the American Continent: Health impacts.

The Saharan Air Layer is a mass of hot, dry air laden with dust that forms over the Sahara and moves towards the Atlantic Ocean. This air mass contains soil dust particles emitted by the action of winds on the African continent. Between June and August, the large-scale patterns of wind circulation transport dust from the Sahara across the tropical North Atlantic Ocean, affecting parts of the Caribbean, Central America, Mexico, even some regions of the United States, and the Mediterranean and Southern Europe. Between December and April, wind circulation patterns facilitate dust transportation from the Sahara to the northern parts of South America and the Amazon. This dust transportation a phenomenon of interest to geosciences and public health because of the potential health impacts of dust dispersion and circulation in the atmosphere. Thus, we assessed the relationship between exposure to Saharan dust (SahD) and its implications for human health in the Americas. We performed a nonsystematic review in the PubMed, Google Scholar, EMBASE, and Scielo databases of studies published between 2000 and 2020 in Portuguese, English, French, or Spanish using the search words "Saharan dust," or "mineral dust," or "desert dust," and "human health." The available direct air pollutants measurements indicate that the pollution level in the cities affected on a constant and prolonged basis is high versus acceptable standards. Further, this review also showed that the negative health effects of SahD are sparsely studied in the Americas.

Distribution and invasion risk assessments of Chrysodeixis includens (Walker, [1858]) (Lepidoptera: Noctuidae) using CLIMEX.

Chrysodeixis includens is a polyphagous pest restricted to the American continent. The occurrence of C. includens is allied, among other factors, by favorable conditions such as temperature, humidity, presence of hosts, and migratory behavior. In this work, we built spatiotemporal species distribution models at continental and global levels for the distribution of C. includens using CLIMEX to determine times and regions favorable for year-round survival and migration of this species and in case of invasion on other continents to apply timely and right phytosanitary measures. Our models estimated high climate suitability for C. includens in Central and large proportions of South America throughout the year. Moreover, there is suitability for C. includens growth in all months of the year in Central and northern part of South America. In the northern hemisphere, these conditions range from April to October, while in mid-southern parts of South America, favorable periods comprise October through June. The countries with the highest suitability for C. includens outside the American continent are located on the African and Asian continents. Our results show variable climate suitability for C. includens during the year that help to understand likely migration pattern in North America. This information would direct efforts for appropriate C. includens management during warm and moist periods of the year. Furthermore, our models notify the need for the development of strategies for the inspection and interception of C. includens especially in central Africa, India, South and Southeast Asia, and Northeast Australia.

Anthelmintic effect of four extracts obtained from Caesalpinia coriaria foliage against the eggs and larvae of Haemonchus contortus.

To investigate the in vitro anthelmintic efficacy of dividivi (Caesalpinia coriaria), a traditional medicinal plant used in Central America and the northern part of South America, extracts from the foliage of this plant were subjected to the egg hatching test (EHT) and larval exsheathment inhibition test (LEIT), against Haemonchus contortus. Four different extracts were evaluated: acetone-water (AW), methanol-water (MW), acetone-water-dichloromethane (AWD) and methanol-water-dichloromethane (MWD). The concentrations used for the EHT and LEIT tests ranged from 500 to 4000 µg mL-1 and six repetitions per concentration. The effective concentrations (EC50) were calculated using Probit analysis. The EC50 for EHT were 2947.0, 3347.0, 3959.6 and 4538.7 µg mL-1 for MWD, MW, AW and AWD, respectively. The EC50 for LEIT were 2883.4, 5927.4, 9876.3 and 9955.4 µg mL-1 for AWD, AW, MWD and MW, respectively. The methanol extracts were the most effective in inhibiting the hatching of eggs, while the acetone extracts showed efficacy in inhibiting larval exsheathment. This study explains the importance that C. coriaria has as a medicinal plant in Central and South American countries.