An extreme wave event in eastern Yucatán,Mexico: Evidence of a palaeotsunami event during the Mayan times     

Javier Lario  Chris Spencer  Teresa Bardají  Ángel Marchante  Victor H. Garduño-monroy  Jorge Macias  Sergio Ortega 《Sedimentology》2020,67(3):1481-1504

The Yucatán Peninsula, Mexico, has typically been considered a tectonically stable region with little significant seismic activity. The region though, is one that is regularly affected by hurricanes. A detailed survey of ca 100 km of the eastern Yucatán and Cozumel coast identified the presence of ridges containing individual boulders measuring >1 m in length. The boulder ridges reach 5 m in height and their origin is associated with extreme wave event activity. Previously modelled tsunami waves from known seismically active zones in the region (Muertos Thrust Belt and South Caribbean Deformed Belt) are not of sufficient scale in the area of the Yucatán Peninsula to have produced the boulder ridges recorded in this study. The occurrence of hurricanes in this region is more common, but two of the most destructive (Hurricane Gilbert 1988 and Hurricane Wilma 2005) produced coastal waves too small to have created the ridges recorded here. In this paper, a new tsunami model with a source area located on the Motagua/Swan Island Fault System has been generated that indicates a tsunami event may have caused the extreme wave events that resulted in the deposition of the boulder ridges.  相似文献   

A method for checking the quality of geographic metadata based on ISO 19157     

Manuel Antonio Ureña-Cámara  Javier Lacasta  Francisco Javier Ariza-López 《International journal of geographical information science》2019,33(1):1-27

With recent advances in remote sensing, location-based services and other related technologies, the production of geospatial information has exponentially increased in the last decades. Furthermore, to facilitate discovery and efficient access to such information, spatial data infrastructures were promoted and standardized, with a consideration that metadata are essential to describing data and services. Standardization bodies such as the International Organization for Standardization have defined well-known metadata models such as ISO 19115. However, current metadata assets exhibit heterogeneous quality levels because they are created by different producers with different perspectives. To address quality-related concerns, several initiatives attempted to define a common framework and test the suitability of metadata through automatic controls. Nevertheless, these controls are focused on interoperability by testing the format of metadata and a set of controlled elements. In this paper, we propose a methodology of testing the quality of metadata by considering aspects other than interoperability. The proposal adapts ISO 19157 to the metadata case and has been applied to a corpus of the Spanish Spatial Data Infrastructure. The results demonstrate that our quality check helps determine different types of errors for all metadata elements and can be almost completely automated to enhance the significance of metadata.  相似文献   

Analysis of the trends in precipitation and precipitation concentration in some climatological stations of Mexico from 1960 to 2010     

Núñez-González  Gerardo 《Natural Hazards》2020,104(2):1747-1761

Natural Hazards - Analysis of precipitation trends as well as the observed trends in precipitation concentration can be useful tools for the identification of natural hazards. This study aimed to...  相似文献   

Dynamics of coastline changes in Mexico     

Valderrama-Landeros  Luis H.  Martell-Dubois  Raúl  Ressl  Rainer  Silva-Casarín  Rodolfo  Cruz-Ramírez  Cesia J.  Muñoz-Pérez  Juan J. 《地理学报(英文版)》2019,29(10):1637-1654

Journal of Geographical Sciences - The goal of our work was to locate and quantify changes that occurred in 66% of the Mexican coastline, based on four land cover maps generated by the Mexican...  相似文献   

Frasnian–Famennian crisis in the Malaguide Complex (Betic Cordillera,Spain)     

Rosario Rodríguez‐Cañero  Agustín Martín‐Algarra 《地学学报》2014,26(1):38-54

Devonian sediments of the Malaguide Complex potentially could include the Frasnian–Famennian boundary, one of the five greatest Phanerozoic biotic crises. Conodont biofacies and microfacies of carbonate clasts from a pebbly mudstone underlying Tournaisian radiolarites allows identification, for the first time in the Malaguide Complex, of Devonian shallow marine environments laterally grading to deeper realms. The clasts yielded Frasnian conodont associations of the falsiovalis to rhenana biozones, with six biofacies that reveal different environmental conditions in their source areas. Source sediments were dismantled and redeposited within the pebbly mudstone, whose origin is tentatively related to one of the events that are associated worldwide with the Frasnian–Famennian crisis. The latter is recorded, in two equivalent Malaguide pelagic successions, by stratigraphic discontinuities, and it was, probably, tectonically and/or eustatically controlled, as in other Alpine‐Mediterranean Paleotethyan margins.  相似文献   

Dynamic modelling of retrogressive landslides with emphasis on the role of clay sensitivity          下载免费PDF全文

Xue Zhang  Scott W. Sloan  Eugenio Oñate 《国际地质力学数值与分析法杂志》2018,42(15):1806-1822

This paper presents a detailed numerical study of the retrogressive failure of landslides in sensitive clays. The dynamic modelling of the landslides is carried out using a novel continuum approach, the particle finite element method, complemented with an elastoviscoplastic constitutive model. The multiwedge failure mode in the collapse is captured successfully, and the multiple retrogressive failures that have been widely observed in landslides in sensitive clays are reproduced with the failure mechanism, the kinematics, and the deposition being discussed in detail. Special attention has been paid to the role of the clay sensitivity on each retrogressive failure as well as on the final retrogression distance and the final run‐out distance via parametric studies. Moreover, the effects of the viscosity of sensitive clays on the failure are also investigated for different clay sensitivities.  相似文献   

Geological Facies Recovery Based on Weighted $$\ell _1$$ ℓ 1 -Regularization     

Calderon  Hernan  Santibañez  Felipe  Silva  Jorge F.  Ortiz  Julián M.  Egaña  Alvaro 《Mathematical Geosciences》2020,52(5):593-617

Mathematical Geosciences - A weighted compressed sensing (WCS) algorithm is proposed for the problem of channelized facies reconstruction from pixel-based measurements. This strategy integrates...  相似文献   

Groundwater characteristics within loessic deposits: the coastal springs of Los Acantilados,Mar del Plata,Argentina     

Federico Ignacio Isla  Orlando Mauricio Quiroz Londoño  Luis Camilo Cortizo 《Environmental Earth Sciences》2018,77(17):610

The urban growth of the southern neighborhoods of Mar del Plata City provoked significant changes in the groundwater balance of the loessic sequences. These regional loessic levels with a significant portion of volcanic ash layers were reported subject to fluoride and nitrate concentrations. Residential houses pump from sands located 70 m depth and withdraw the sewages to depths less than 5 m. These effects cause significant local and seasonal (summer) increments of the water table outcropping via springs at certain unconformities of the coastal cliffs. A mathematical model was applied to analyze the water level lowering at the productive levels, while there is a decrease in the quality of the upper levels subject to waste discharges. Much of this groundwater flow is concentrated in unconformities between different types of sediments. Human activities have affected the aquifer dynamics increasing the groundwater pumping rates and the return velocity of the sewages. This should be considered in the management strategies of coastal hydric resources.  相似文献   

Non-woven polypropylene fabric modified with carbon nanotubes and decorated with nanoakaganeite for arsenite removal     

J. Tomaszewska  P. Smektała  I. Zgłobicka  J. Michalski  K. J. Kurzydłowski  P. Krzemiński  C. Escudero-Oñate 《International Journal of Environmental Science and Technology》2018,15(9):1831-1842

Due to its harmful impact on human health, the presence of heavy metals, metalloids and other toxic pollutants in drinking or irrigation water is a major concern. Recent studies have proved that nanosized adsorbents are significantly more effective than their microsized counterparts. Particular attention has been given to nanocomposites with nanoadsorbents embedded in matrixes that could provide stability to the material and contribute to eliminating problems that may appear when using conventional granular systems. This study presents the preparation of a novel hybrid filter from a commercially available polypropylene (PP) non-woven fabric matrix modified with multiwall carbon nanotubes (MWCNT) and iron oxy(hydroxide) nanoparticles, and its use in the removal of As(III). A Box–Behnken statistical experimental design has been chosen to explore relevant variables affecting the filter performance: (1) As(III) concentration, (2) pH and (3) sorbent dose. From an As(III) concentration of 10 mg L^?1, at pH 6.5 and with a sorbent dose of 5 g L^?1, the PP filter modified with MWCNT removes 10% of the initial metalloid concentration, reaching a capacity of 0.27 mg g^?1. After modification with iron oxy(hydroxide), the performance of the material is largely enhanced. The filter, under the same conditions, removes 90% of the initial As(III) concentration, reaching a capacity almost tenfold higher (2.54 mg g^?1). This work demonstrates that the developed hybrid filter is effective toward the removal of As(III) in a wide range of pHs. A cubic regression model to compute the removal of the filter as a function of pH and sorbent dose is provided.  相似文献   

Influence of the sediment delivery ratio index on the analysis of silting and break risk in the Plasencia reservoir (Central System,Spain)     

Sánchez  Y.  Martínez-Graña  A.  Santos-Francés  F.  Yenes  M. 《Natural Hazards》2018,90(3):1407-1426

The random forest method was used to generate susceptibility maps for debris flows, rock slides, and active layer detachment slides in the Donjek River area within the Yukon Alaska Highway Corridor, based on an inventory of landslides compiled by the Geological Survey of Canada in collaboration with the Yukon Geological Survey. The aim of this study is to develop data-driven landslide susceptibility models which can provide information on risk assessment to existing and planned infrastructure. The factors contributing to slope failure used in the models include slope angle, slope aspect, plan and profile curvatures, bedrock geology, surficial geology, proximity to faults, permafrost distribution, vegetation distribution, wetness index, and proximity to drainage system. A total of 83 debris flow deposits, 181 active layer detachment slides, and 104 rock slides were compiled in the landslide inventory. The samples representing the landslide free zones were randomly selected. The ratio of landslide/landslide free zones was set to 1:1 and 1:2 to examine the results of different sample ratios on the classification. Two-thirds of the samples for each landslide type were used in the classification, and the remaining 1/3 were used to evaluate the results. In addition to the classification maps, probability maps were also created, which served as the susceptibility maps for debris flows, rock slides, and active layer detachment slides. Success and prediction rate curves created to evaluate the performance of the resulting models indicate a high performance of the random forest in landslide susceptibility modelling.  相似文献