Search

Lifelines such as drinking water and sewage systems provide the means and conveyance for daily critical services, and they are essential systems for recovery operations after a damaging earthquake. Therefore, earthquake damage to lifeline components needs to be reliably assessed for a possible future seismic scenario. This study presents an earthquake damage assessment of buried pipeline networks in the Lima Metropolitan Area (LMA). It includes seismic hazard analysis, a review of pipeline network datasets, and the selection of empirical fragility functions. Deterministic seismic hazard analysis was performed for an inter-plate earthquake scenario using ground motion prediction equations and site conditions to compute the distribution of the peak ground velocity (PGV). Recommendations are offered for an adequate selection of fragility functions developed in other regions, and a logic tree of fragility functions is proposed to be used in pipelines of LMA according to the data of pipeline damage after the 2007 Pisco Earthquake. Finally, the pipeline repair ratios and the total number of repairs are estimated for the earthquake scenario, and the results are geographically presented for each pipeline network.

Non-engineered confined masonry dwellings are characterized by having different masonry units. One of the most common cases in the Lima Metropolitan Area is that this type of dwelling has its first floors with handmade solid units and upper floors are composed of industrial horizontal hollowed (tubular) bricks. Nonlinear static analysis by the incrementally increasing loading pattern is inadequate to estimating earthquake response of structures with height irregularity, such as non-engineered confined masonry dwellings, because the loading pattern changes during the history of reversal loads due to damaging earthquakes. This paper presents the effect of nonlinear static analysis using adaptive loading patterns in confined masonry dwellings when the type of masonry units changes drastically. Nonlinear static analyses are applied using non-adaptive and adaptive displacement-based pushover procedures. A series of nonlinear time history analyses are also conducted to measure the error in the estimation of the seismic response. The adaptive loading pattern is based on displacement approximation by the modal analysis at each step of incremental-increasing loads. The load pattern is updated considering the modal analysis of an equivalent linear model using the equivalent stiffness of the structure at the secant of the maximum previous response. The application of the adaptive loading pattern in nonlinear static analysis significantly approximates the earthquake response of confined masonry dwellings with height irregularity provided by the change of masonry bricks.

During big earthquakes, one of the challenges for the decision maker is the estimation of the resources for the attention of the disaster which is computed based on the casualties and injured people, which is generated by damaging earthquake. In this investigation, two criteria for the estimation of casualties during damaging earthquake were presented for Mw>6.5 in one target area, namely, Chorrillos district in the Lima metropolitan. First criterion considers the compilation of existing data that reports the casualties on damaged cities with a population density involved, considering the lifestyle, the time of occurrence, the season of the year, that could influence in the number of victims, which is normalized to avoid temporary effects in the estimation. The second criterion considers the output generated prior computed process such earthquake hazard, microzoning and risk analysis of the target area. Here a series of identification of parameters has been computed such as location of the source of earthquake, depth and epicentral distance, distribution of population, social levels, and others, to estimate the risk. For the computing of the number of casualties in the affected area, a relation between the magnitude and risk is developed. Both criteria provided results which with an uncertain measure, but not so far from each other. That gives us confidence in this approach. Also, we evaluate the estimation with the major earthquake’s scenarios for the region especially in Peru, with reasonable results.

The Lima metropolitan area is in a prone earthquake zone, which is exposed to a seismic gap; this can result in Mw 8.9 megathrust earthquake in the central Peru. After the Pisco earthquake in 2007, risk management policies changed in Peru and are improving annually. Thus, more resources are destinated to assessing earthquake hazard, vulnerability, and risk in districts of the Lima metropolitan area mainly; nevertheless, they are limited to cover in detailed the whole extension of probable affected area after this potential megathrust earthquake. Data of buildings in the Lima metropolitan area were analyzed in this paper, to provide useful information in the development of rapid methodologies of identification of buildings. The Japan Peru Center for Earthquake Engineering and Disaster Mitigation (CISMID) gathered these data from 2010 to 2021 in field surveys to conduct vulnerability and risk studies; the survey of building characteristics consisted of obtain mainly the number of stories, predominant material, structural systems, type of occupancy, and state of conservation. Vulnerability and risk studies for districts of the Lima metropolitan area were conducted by considering one representative building in one block. Results showed that the predominant material in the Lima metropolitan area is masonry, used in different structural systems, such as confined masonry and other which are nonengineered structures. Also, two-story buildings are predominant in the target area, followed by one and three-stories buildings. Risk assessment for the Lima metropolitan area and the study area were conducted using the data from the characterization of structural typologies obtained in this study. Approximately, 47.72% and 58.67% of buildings presented a very high-risk level in the Lima metropolitan area and the study area, respectively, under the expected earthquake scenario due to the seismic gap in the central Peru.

The conjunction of seismic records and site effect parameters can lead to the adequate estimation of seismic indexes in urban areas. In this regard, this study uses the map of soil amplification factors obtained in previous studies and the availability of time history waveforms at different locations throughout Metropolitan Lima and Callao to estimate the geospatial distribution of maximum values of horizontal acceleration after the occurrence of earthquakes. Results for three earthquakes of intermediate magnitude and distinct epicenter locations are publicly available in an online system created within the framework of this study (Amaru Peru) and showed that amplified motions could be mainly observed in the lowlands of populated slopes as well as in the eolian sandy deposits.

Structural health monitoring based on vibration measurements is a process that implements the instrumentation of sensors and methodologies to provide information regarding the condition of a structure, which allows the evaluation of the safety and integrity of structural systems. Because of this, in the past decades, several algorithms have been developed; among them, the wavelet transform is considered an efficient method for the elimination of the error contained in the acceleration recorded by the sensors. However, due to the complex nature of earthquakes and the particularity of the structural systems, the parameters used by the wavelet transform for error elimination in the seismic response are frequently variable. This paper proposes a method to get the seismic response of a base-isolated building subjected to ground-strong motions through numerical simulations of a mathematical model of the structure, using synthetic records based on historical seismic events occurring in Peru. In this way, the research found that the optimal intrinsic parameters of the building correspond to an approximate frequency interval of 0.20 to 6.25 Hz. Finally, the results show that this method is valid and can be reliably applied in structural health monitoring systems.

Lima, Peru's capital, has about 9.6 million inhabitants and keeps attracting more residents searching for a better life. Many citizens, without access to housing subsidies, live in informal housing and shack settlements. A typical social phenomenon in Lima is the sudden illegal occupation of areas for urban settlements. When such areas are unsafe against natural hazards, it is important to relocate such a population to avoid significant future losses. In this communication, we present an application of Sentinel-1 synthetic aperture radar (SAR) images to map the extension of a recent occupation of an area with unfavorable soil conditions against earthquakes.

Recent advances in the understanding of deltaic deposits provide new tools for the study and analysis of deltaic deposits in shallow epicontinental seas. After the introduction of sequence stratigraphic concepts, meter-scale coarsening and thickening upward successions have been considered as “parasequences” originated by high-frequency sea-level changes. Nevertheless, recent studies enhanced the importance of wave-aided low-dense hyperpycnal flows in transporting fine-grained sediments in shallow shelfal areas. These poorly-known (and at the same time very common) types of delta, known as hyperpycnal littoral deltas (HLD), develop very low gradient progradational units, controlled by changes in the sediment supply instead of sea level changes. These small-scale progradational units are very common in shallow epicontinental seas like the Lower Cretaceous Agrio Formation in the Neuquen Basin. This study provides a first detailed analysis of hyperpycnal littoral deltas from the Agua de la Mula Member (upper Hauterivian–lower Barremian) of the Agrio Formation. This unit has been studied in three locations near Bajada del Agrio locality in the central part of the Neuquen Basin, Argentina. Six sandy facies, three heterolithic facies, three muddy facies and four calcareous facies were recognized. From facies analysis, three facies associations could be determined, corresponding to offshore/prodelta, distal ramp delta and proximal ramp delta. The three stratigraphic sections discussed in this study are internally composed of several small-scale sequences showing a coarsening and thickening upward pattern, transitionally going from muddy to sandy wave-dominated facies, and ending with calcareous bioclastics levels on top. These small-scale sequences are interpreted as delta front deposits of wave-influenced hyperpycnal littoral deltas, punctuated by calcareous intervals accumulated during periods of low sediment supply. It is interpreted that the development of hyperpycnal littoral deltas could have been facilitated by a decrease in sea water salinity related to an increasing runoff.

En esta contribución se analiza el concepto de PERSONA entre los mayas de Yucatán, desde una perspectiva semiótica y considerados el desarrollo y cambio de la significación que ha experimentado este grupo étnico, a través de los siglos de contacto y dominación europea. Se exploran los rasgos distintivos que los mayas emplean para caracterizar el concepto de persona. Es a través de la semiosis que podemos comprender y describir la significación y el desarrollo de este signo hasta penetrar gradualmente a la cabal manifestación sígnica en esta lengua; esto nos permite analizar de manera más clara y explicar el complejo fenómeno de la identidad. El trabajo explora la noción de persona, a partir de los rasgos etnosemánticos característicos y la oposición de persona versus no persona, además de los elementos pragmáticos que resultan no tan solamente complementarios, sino cruciales para la comprensión de este concepto en el ámbito de la identidad de este grupo étnico.

El objetivo del trabajo es presentar un sencillo modelo biocultural para entender al ser humano a partir de la categoría de persona. Se propone comprender a la persona a partir de los siguientes componentes: la apariencia, su fundamento, la conciencia, su identidad, el desarrollo, la vida social y la sacralidad. El modelo se compone de tres semiosis: herencia, desarrollo y momentos clave en la vida. La semiosis de herencia presenta todo lo que al heredar le hace persona, desde lo evolutivo de la especie hasta lo histórico. La semiosis de desarrollo ejemplifica el contenido ontogénico de hacerse persona y cómo hace posible la unidad biocultural de lo humano. La semiosis de momentos clave presenta los momentos más importantes en la vida para cada persona. Como conclusiones se propone que la persona sirve como índice de lo humano y puede estudiarse para responder a qué es el ser humano.

This essay shows an organization of the explanation of the human being as a humanized animal. It is based on explaining the human tendency to educate and generate human beings as the peculiar emergence of the human being. To explain the human quality, it addresses the understanding of human development that is humanized in society, that builds a reality of being human in the culture, and to become human as an aim. Humanization comes as the opposite of animality in whose dynamics the human being is. Several examples of how human beings act in making and becoming human are presented. We propose a process and how important it is to respond to; what are human beings, in a world like the current one that does not have a firm foundation to build knowledge. Este ensayo muestra una organización de la explicación del ser humano como animal humanizado. Se fundamenta en explicar la tendencia humana de educar y generar seres humanos como la emergencia peculiar del ser humano. Para explicar la calidad humana, se aborda la comprensión del desarrollo humano que se humaniza en sociedad, que construye una realidad del ser humano en la cultura y del hacerse humano como fin. La humanización surge como lo opuesto a la animalidad en cuya dinámica se encuentra el ser humano. Se presentan varios ejemplos de cómo actúan los seres humanos al crear y convertirse en humanos. Proponemos un proceso y lo importante que es responder a qué somos los seres humanos, en un mundo como el actual que no tiene una base firme para construir conocimiento.

Deltas constitute complex depositional systems formed when a land-derived gravity-flow (carrying water and sediments) discharges into a marine or lacustrine standing body of water. However, the complexity of deltaic sedimentary environments has been oversimplified by geoscientists over the years, considering just littoral deltas as the unique possible type of delta in natural systems. Nevertheless, a rational analysis suggests that deltas can be much more complex. In fact, the characteristics of deltaic deposits will depend on a complex interplay between the bulk density of the incoming flow and the salinity of the receiving water body. This paper explores the natural conditions of deltaic sedimentation according to different density contrasts. The rational analysis of deltaic systems allows to recognize three main fields for deltaic sedimentation, corresponding to (1) hypopycnal (2) homopycnal and (3) hyperpycnal delta settings. The hypopycnal delta field represents the situation when the bulk density of the incoming flow is lower than the density of the water in the basin. According to the salinity of the receiving water body, three different types of hypopycnal littoral deltas are recognized: hypersaline littoral deltas (HSLD), marine littoral deltas (MLD), and brackish littoral deltas (BLD). The basin salinity will determine the capacity of the delta for producing effective buoyant plumes, and consequently the characteristics and extension of prodelta deposits. Homopycnal littoral deltas (HOLD) form when the density of the incoming flow is roughly similar to the density of the water in the receiving basin. This situation is typical of clean bedload-dominated rivers entering freshwater lakes. Delta front deposits are dominated by sediment avalanches. Typical fallout prodelta deposits are absent or poorly developed since no buoyant plumes are generated. Hyperpycnal deltas form when the bulk density of the incoming flow is higher than the density of the water in the receiving basin. The interaction between flow type, flow density (due to the concentration of suspended sediments) and basin salinity defines three types of deltas, corresponding to hyperpycnal littoral deltas (HLD), hyperpycnal subaqueous deltas (HSD), and hyperpycnal fan deltas (HFD). Hyperpycnal littoral deltas are low-gradient shallow-water deltas formed when dirty rivers enter into brackish or normal-salinity marine basins, typically in wave or tide-dominated epicontinental seas or brackish lakes. Hyperpycnal subaqueous deltas represent the most common type of hyperpycnal delta, with channels and lobes generated in marine and lacustrine settings during long-lasting sediment-laden river-flood discharges. Finally, hyperpycnal fan deltas are subaqueous delta systems generated on high-gradient lacustrine or marine settings by episodic high-density fluvial discharges.

Interpretation of the continental or marine character of sediments on the basis of the paleosalinity is increasingly based on the concentration of some trace elements. The paleosalinity can be affected, however, also in deep-marine environments, by discharge peaks of major sediment-laden rivers. These induce hyperpycnal flows that run down the basin slope. The huge volume of fresh water gradually mixes with the ambient saline seawater, diminishing the paleosalinity. The temporary lowered paleosalinity may be preserved in the sedimentary record in the form of ‘diverging’ concentrations of trace elements and trace-element ratios. This is exemplified for the Early Cretaceous Lingshandao Formation on Lingshan Island (western Yellow Sea). It was found during field work and geochemical analysis that hyperpycnal currents may not only lower the salinity of a deep-marine environmental setting, but may also carry along continental plant fragments and other biological remains, which may obscure the marine character of the sediments. It is deduced that detailed facies analysis in the field is consequently required to reveal the true character of a marine environment.

A Miocene macroflora recovered from Ñirihuau Formation sediments exposed at Quebrada Vera site in northwesterern Patagonia, Argentina, is recorded and described for the first time. The assemblage is composed exclusively of free-sporing plants, mainly by Equisetum remains with subordinate occurrences of four fern morphotypes (represented by bi-, tri- and pinnate fronds). Equisetum imprints and molds include distinctive jointed stems with whorls of linear and basally fused leaves, numerous scars of lateral branches arranged in a radially symmetrical pattern situated at the nodes, and nodal diaphragms of up to 4 cm in diameter. The large size and regular branching of the stems link the fossils to the South American giant members of the genus and they probably represent a new fossil species. This is the first conclusive fossil record of a giant Equisetum worldwide, and consequently, it is biogeographically and evolutionarily relevant. The new findings attest that members of the giant horsetail clade were components of the Patagonian vegetation in the Miocene, implying that the age of the clade must predate that estimated from morphological and/or molecular data. The plant fossil assemblage represents part of a wetland community probably growing close to a riverside or lakeshore in coincidence with previous sedimentological estimates.

Being the main oil-bearing basin of Argentina, the Neuquén Basin contains a well-documented stratigraphic record of continental and marine sedimentation during the Jurassic and Cretaceous in the western margin of Gondwana. Marine sedimentation started in the Early Jurassic with the deposition of the ofshore to prodelta shales of the Los Molles Formation, the basal unit of the Cuyo Group. A palynological study of outcrop samples of the Los Molles Formation at two localities,Puente Picún Leufú, southern Neuquén Basin, and Cordillera del Viento, central basin area, is presented. The palynological evidence allows inferring two diferent palaeoceanographic contexts during the deposition of the Los Molles Fm. At Puente Picún Leufú and the lower part of the Cordillera del Viento localities, the record of acritarchs and prasinophytes suggests a stratiied water column, suboxic-to-anoxic bottom conditions, and a reduced salinity within the photic zone, associated with a marginal marine environment under restricted oceanic circulation. These conditions would have last at least until the Early Bajocian. Conversely, at the middle and mainly the upper part of Cordillera del Viento locality, the predominance of dinocysts in the assemblages indicates a hydrographically unstable shelf (non-stratiied water mass column) with welloxygenatedbottom waters developed under open-marine settings with non-restricted oceanic circulation. The abundance and diversity of dinocyst assemblages are comparable with those observed in the Late Callovian Lotena Formation. These evidences suggest an open oceanic circulation due to the establishment of diferent seaways in the Neuquén Basin, during the inal accumulation of the Los Molles Formation (Early Callovian). Fil: Olivera, Daniela Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; Argentina Fil: Martinez, Marcelo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; Argentina Fil: Zavala, Carlos Alberto. Universidad Nacional del Sur. Departamento de Geología; Argentina. GCS Argentina; Argentina Fil: Di Nardo, Juan. Universidad Nacional del Sur; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina Fil: Otharán, Germán Aníbal. Universidad Nacional del Sur; Argentina. GCS Argentina; Argentina

RESUMEN El modelo sedimentológico convencional relaciona la acumulación de rocas sedimentarias de grano fino (

Fil: Ponce, Juan J. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología; Argentina. Fil: Canale, Nerina. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología; Argentina. Fil: Zavala, Carlos. Universidad Nacional del Sur; Argentina. Fil: Ponce, Juan J. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fil: Zavala, Carlos. GCS Argentina SRI; Argentina. The recent article published byPazos et al. (2019)consists of adescription of one tyreophoran track in deltaic deposits of the MiddleJurassic Lajas Formation, Neuquén basin, Argentina. In their sedi-mentological interpretation of the succession, the authors referred toseveral aspects of previous contributions (Zavala and González, 2001;Zavala, 2002;Canale et al., 2015), incurring in omissions and incorrectstatements that we consider should be clarified, in order to avoidgenerating confusion in one of the classic Lajas Formation section in theNeuquén basin. The recent article published byPazos et al. (2019)consists of adescription of one tyreophoran track in deltaic deposits of the MiddleJurassic Lajas Formation, Neuquén basin, Argentina. In their sedi-mentological interpretation of the succession, the authors referred toseveral aspects of previous contributions (Zavala and González, 2001;Zavala, 2002;Canale et al., 2015), incurring in omissions and incorrectstatements that we consider should be clarified, in order to avoidgenerating confusion in one of the classic Lajas Formation section in theNeuquén basin.

Marine sedimentation in the Neuquen Basin started in the Early Jurassic with the accumulation of a progradational clastic system: the Cuyo Group. This sedimentary cycle begins with offshore shales of the Los Molles Formation, transitionally overlaid by shelfal to littoral sandstones and conglomerates of the Lajas Formation. According to the current stratigraphic schema, in the southern Neuquen Basin the Cuyo Group ends with continental red beds of the Challaco Formation, a unit interpreted as being the proximal equivalent of the Lajas Formation. Nevertheless, recent studies performed in the Picun Leufu area, complemented with regional stratigraphic evidence, suggest that the accumulation of these stratigraphic units is more likely related to a complex depositional scenario that involves tectonic activity during the Jurassic along the Huincul Arch. The uplift and exposure of Jurassic rocks along the Huincul Arch divided the basin into two sub-basins, each one having a different stratigraphy for the Middle-Late Jurassic time span. The stratigraphic analysis revealed that the red beds traditionally located at the top of the Cuyo Group in fact represent two different stratigraphic units separated by a regional unconformity. The lower unit (1) sharply overlies the Lajas Formation, corresponding to the Challaco Formation s.s. This unit was accumulated in a brackish lacustrine basin developed southward of the Huincul Arch (Picun Leufu Sub-basin). The upper unit (2) corresponds to the Bosque Petrificado Formation and is stratigraphically located at the base of the Lotena Group. The Bosque Petrificado Formation was accumulated in a fluvial to marine environment developed in the southern Neuquen Basin. Paleocurrent analysis suggests a sediment supply from the northeast, evidencing a local source of sediments related to an uplifted area. Recent biostratigraphic studies performed in the Bosque Petrificado and Lotena formations revealed an Early Callovian-Early Oxfordian age for these deposits.

This study documents for the first time the occurrence of Shanbeipollenites proxireticulatus Schrank in levels of the Vaca Muerta Formation, Neuquén Basin, Argentina. It represents the first record of this species in high latitudes of the Southern Hemisphere. The Argentinian specimens are associated with useful palynostratigraphical indicators which suggest an early Valanginian age for the palynoflora yielding S. proxireticulatus. Therefore, this finding constitutes the first record from the Cretaceous. This taxon is related to the orders Cycadales/Bennettitales/Ginkgoales. During the Cretaceous in Patagonia cycads and bennettitaleans groups show marked adaptations to warm and strongly seasonal dry climate periodically influenced by volcanic activity. The paleogeographic distribution of the records of S. proxireticulatus, symmetrically located on both sides of the equator, together with its relationship with the climate zones or Biomes, suggest that the parental plants of this pollen grain thrived under warm climate and probably stressed paleoenvironmental conditions. Since the studied sample is located near 1000 m below the Intravalanginian unconformity, and older age (i.e. late Berriasian) cannot be discarded. Fil: Olivera, Daniela Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; Argentina Fil: Martinez, Marcelo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; Argentina Fil: Zavala, Carlos Alberto. Universidad Nacional del Sur. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Otharán, Germán Aníbal. Universidad Nacional del Sur. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Marchal, Denis. Pampa Energía S.A.; Argentina Fil: Köhler, Guillermina. Pampa Energía S.A.; Argentina

The ongoing exploration for shale oil and gas has focused sedimentological research on the transport and deposition mechanisms of fine-grained sediments, and more specifically on fine-grained mass-flow deposits. It appears, however, that no easily applicable classification scheme for gravity-flow deposits exists, and that such classifications almost exclusively deal with sandy and coarser sediments. Since the lack of a good classification system for fine-grained gravity flow deposits hampers scientific communication and understanding, we propose a classification scheme on the basis of the mud content in combination with the presumed transport mechanism. This results in twelve types of gravity-flow deposits. In order to show the practical applicability of this classification system, we apply it to the Triassic lacustrine Yanchang Formation in the southern Ordos Basin (China), which contains numerous slumps, debris–flows deposits, turbidites and hyperpycnites. The slumps and debrites occur mostly close to a delta front, and the turbidites and hyperpycnites extend over large areas from the delta slopes into the basin plain. The case study shows that (1) mud cannot only be transported but also deposited under active hydrodynamic conditions; (2) fine-grained gravity-flow constitute a significant part of the lacustrine mudstones and shales; (3) muddy gravity flows are important for the transport and deposition of clastic particles, clay minerals and organic matter, and thus are important mechanisms involved in the generation of hydrocarbons, also largely determining the reservoir capability for unconventional petroleum.

Shallow-water deltas remain enigmatic in terms of placing the observed facies within a coherent process-based depositional model. Here we report tank experiments on mouth-bar formation from shallow water pure and stratified jets that, combined with recent flume experiments on bedforms, suggest new interpretations of field observations from shallow-water delta outcrops. Our experiments imply that the height, geometry and bedforms of the mouth bars depend on the jet properties and grain size of the supplied sediment. Pure jets with very coarse-grained sediment formed a high and steep mouth bar that is characterised by steep angle-of-repose cross bedding with related avalanche processes (grain flows) on the lee side. The experiments with stratified jets imply that mouth-bar deposition and growth are dominated by supercritical density flows that evolve from the initial jets on the lee side of the growing mouth bar. In stratified jets with very coarse-grained sediment, deposition on the mouth-bar lee side was both from grain-flow avalanches and density flows. While deposition on the upper lee slope was dominated by grain flows, a concentric field of low relief, asymmetric, downflow-migrating bedforms evolved on the lower slope and beyond the mouth bar. In the stratified jet with medium-grained sediment a very low relief mouth bar formed within a concentric field of low, asymmetric, downflow-migrating bedforms covering the entire lee slope and the area beyond. Many previous field studies show that mouth bars deposited from dense stratified jets (hyperpycnal flows) are characterised by a distinct facies assemblage of coarse-grained cross-stratified or low-angle cross-stratified sandstone passing downslope into finer-grained plane-parallel, or “quasi-parallel” laminated sand and into climbing-ripple cross-laminated sandstone. Comparison to flume and tank experiments suggests that the proximal coarse-grained planar and trough cross-stratified sandstones could represent deposition by supercritical dunes that pass downslope into antidunes, characterised by sinusoidal stratification and/or low-angle cross stratification. The repeated vertical transition between antidune deposits and climbing-ripple cross-laminated sandstone may indicate the superposition of ripples onto antidunes in finer-grained sediments, indicating ripple formation under supercritical flow conditions. Similar bedforms/sedimentary structures have previously been interpreted as hummocky cross-stratification or swaley cross-stratification and attributed to combined flows in storm-dominated settings, which probably in some cases must be revised.

For 30 years the Structural Laboratory of the Peru Japan Center for Earthquake Engineering Research and Disaster Mitigation (CISMID) from the Faculty of Civil Engineering (FIC) of the National University of Engineering (UNI) is been testing different types of structural system, mainly confined masonry walls. In that sense, large number of experiments have been conducted in confined masonry walls. Analytical model for capacity curve is presented for walls with different types of masonry units, such as industrial hollow bricks, solid handmade bricks and tubular bricks which are the most representative units in Metropolitan Lima and Callao. Tetra-linear models are calibrated with experimental results in order to provided generalized model in terms of sensitive parameters which determines the capacity curve for flexural shear failure mechanism, such as longitudinal and transversal steel ratio, slenderness ratio and axial load ratio where shear stress is observed in the cracking, yielding, maximum and ultimate points.

Non engineering dwellings represents 83% of the stock of housing in emerging areas of Lima city. These dwellings are build with non-appropriated masonry bricks with walls that limits don´t meet the displacement control of the earthquake design standards NTE-030 and NTE-070. Considering the database of structural test of 33 years of experimental studies of the Structural Laboratory of CISMID, typical behavior curves are studied in order to propose damage limit state for masonry walls: build with industrial bricks, build with handmade bricks and build with horizontal hollow tubular bricks. Also, results of full-scale test on masonry house performed in the laboratory are studied. Ranges of inelastic development limit states of walls are proposed from the test results of full-scale test of the three types of masonry. Big difference in the capacity of walls with tubular bricks in comparison with the others types are found. Also limit drift values threshold are propose to be use in the analytical modelling of wall structures with handmade or tubular bricks. These proposal limits are smaller than the limit of NTE-030 standard.

Subaqueous sediment gravity-flow (SSGF) deposits have recently been recognized as a major reservoir plays in lacustrine basins. Research on their genesis and depositional models are crucial to understand gravity flow evolution and the distribution of their deposits. This study analysed SSGF deposits in the third member of the Shahejie Formation in the Jiyang Depression, Eastern China, based on 3-D seismic data, well-log data, and core observations. The types and origins of SSGF, the distribution patterns and depositional models of SSGF deposits have been investigated. The dominant types of SSGF include: muddy debris flows, sandy debris flows, high density turbidity currents, surge-like low density turbidity currents, and quasi-steady low density turbidity currents, which are mainly caused by river floods and sediment failures. The overall distribution of SSGF deposits is controlled by the sediment supplies, basin structure, and sequence stratigraphic framework. Paleotopography, flood energy, triggering mechanism, and the slope angle of the delta front are also important. SSGF deposits associated with river floods can be further subdivided into elongated and fan-shaped deposits. Elongated sandstones are composed predominantly of bedload-dominated and suspension load-dominated hyperpycnal flow deposits. The fan-shaped sandstones can be subdivided into an inner fan, a middle fan, and an outer fan. Inner fan deposits are dominated by gully-filling debrites. Middle fan deposits are composed predominantly of channel-fill deposits, while outer fan deposits consist of thin bedded and laterally extensive lobe intervals. SSGF deposits triggered by sediment failures can be further subdivided according to their proximity to slumping: proximal, intermediate and distal parts. The proximal deposits are composed predominantly of slide and slump deposits. The intermediate deposits are dominated by sandy debrite tongues, while the distal deposits are composed predominantly of thin-bedded, surge-like, low-density turbidites. This study offers some insight into the types, origin of gravity-flow, as well as the distribution of their deposits in a lacustrine rift basin.

Resumen Introducción: Actualmente, se está tratando de cambiar el modelo tradicional de enseñanza, por uno guiado por las necesidades de aprendizaje del estudiantado. El modelo de aprendizaje invertido busca favorecer el aprendizaje mediante un trabajo coordinado por docentes y estudiantes. Objetivo: Analizar la implementación del aprendizaje invertido para la mejora y logro de metas de aprendizaje en el curso de metodología de la investigación. Metodología: Diseño cuasiexperimental, de intervención, prospectivo, de corte longitudinal. Lugar: Facultad de Ciencias de la Salud de una universidad privada. Participantes: 81 estudiantes de pregrado. Intervenciones: Se seleccionó una muestra no probabilística por conveniencia y luego se implementó el modelo aula invertida. La primera medición se realizó en la tercera semana de clases y la segunda medición en la décimo quinta, mediante un instrumento validado y con índice de confiabilidad total de 0,79. Asimismo, se utilizó la plataforma educativa Edoome, con características de sistema de gestión de aprendizaje de código abierto. Resultados: 93,8% manifestó que el profesorado y el estudiantado desarrollan las clases; 29,6% estudia previamente los contenidos y 39,5% realiza un resumen de la clase, donde predomina el trabajo colaborativo. 74,0% manifestó que el aprendizaje invertido facilitó su aprendizaje y obtuvo mejores calificaciones en el examen final. Conclusión: El modelo demostró mejorar y ser efectivo para el logro de las metas de aprendizaje en el Curso de Metodología de la Investigación y su implementación se está convirtiendo en una necesidad para el sistema educativo universitario. Abstract Introduction: Teachers are currently trying to change the traditional model to one based on learning needs of the students. The flipped (inverted) learning model seeks to promote learning through a work jointly led by teachers and students. Objective: To analyze the implementation of the flipped learning model in the achievement of goals in the Research Methodology course. Methodology: a prospective, longitudinal, quasi-experimental research design. Place: Health Sciences Faculty, at a private University. Participants: 81 undergraduate students. Interventions: A convenience non-probability sample was selected; then, the flipped learning model was implemented. The first analysis was performed in the third week of classes, and the second one in the fifteenth week, using a valid instrument with a total reliability index of 0.79. The Edoome educational platform was also used; it has characteristics of an open source learning management system. Results: 93.8% stated that the teacher and the students develop the class, 29.6% previously study the contents, and 39.5% make a summary of the class, meaning that the collaborative work predominates. 74.0% stated that the flipped learning facilitated their learning and obtained better grades in the final exam. Conclusion: The flipped classroom model proved to be effective to achieve learning goals in the Research Methodology course, and its implementation is becoming a need for the university education system. Resumo Introdução: Atualmente, está se tratando de mudar o modelo tradicional de ensino, por um guiado pelas necessidades de aprendizagem por parte dos estudantes. O modelo de aprendizagem reverso busca favorecer a aprendizagem mediante um trabalho coordenado por docentes e estudantes. Objetivo: Analisar a implementação da aprendizagem reversa para a melhora e alcance das metas de aprendizagem no decorrer da metodologia de pesquisa. Metodologia: Desenho quase-experimental, intervenção, corte longitudinal prospectivo. Lugar: Faculdade de Ciências da Saúde de uma universidade privada. Participantes: 81 estudantes pré-universitários. Intervenções: Selecionou-se uma mostra não probabilística por conveniência e depois se implementou o modelo de aula invertida. A primeira medição foi feita na terceira semana de aulas e a segunda na décimo quinta semana, utilizando um instrumento validado com um índice de confiabilidade total de 0,79. Além disso, foi utilizada a plataforma educacional Edoome, com características de sistema de gerenciamento de aprendizagem de código aberto. Resultados: 93,8% manifestaram que docentes e estudantes participam das classes; 29,6% estudam previamente os conteúdos e 39,5% realizam um resumem da classe, onde predomina o trabalho colaborativo. 74,0% manifestaram que a aprendizagem investida facilitou sua aprendizagem e obtiveram melhores qualificações no exame final. Conclusão: O modelo demonstrou melhoras e ser efetivo para a realização dos objetivos de aprendizagem no Curso de Metodologia de Pesquisa e sua implementação está se tornando uma necessidade para o sistema de ensino universitário.

The Morne L'Enfer Formation outcrops near Fullarton, Trinidad, expose an erosional surface between the shelf deposits below and a prograding clastic wedge of the late Pliocene paleo-Orinoco system above. The surface exhibits similarities as well as dissimilarities with examples of Regressive Surfaces of Marine Erosion (RSMEs) in wave-influenced shelf settings and also with incised valleys inherited from fluvial incision of shelf during a forced regression episode. However, detailed ichnological studies reveal that the surface is a subaqueous, autogenically controlled, erosional surface on a shelf dominated by the hyperpycnal and hypopycnal discharges with transient wave influence. Integration of ichnological and sedimentological characteristics also suggests complicated interrelationships among different stress factors affecting the infauna in different subenvironments, especially the irregular echinoids. The delta prograded subaqueously through autogenically establishing its lobe on the open shelf without stratigraphically significant erosional removal of sediments. In the subaqueously prograding clastic wedge, the fluvial influence pertains high stress conditions not only for the adult infauna, but also for their larvae within the water column, especially in and near the subaqueous distributary channels.