Spatial distribution and estimation of rainfall trends and erosivity in the Epitácio Pessoa reservoir catchment,Paraíba,Brazil   总被引：1，自引：0，他引：1  

da Silva  Richarde Marques  Santos  Celso Augusto Guimarães  da Costa Silva  Jorge Flávio Cazé Braga  Silva  Alexandro Medeiros  Brasil Neto  Reginaldo Moura 《Natural Hazards》2020,102(3):829-849

Natural Hazards - The main goals of this study are to better understand the spatial and temporal variabilities in rainfall and to identify rainfall trends and erosivity for the period from 1963 to...  相似文献   

A dynamic stability analysis for the Olinalá landslide,northeastern Mexico     

Salinas-Jasso  Jorge A.  Montalvo-Arrieta  Juan C.  Chapa-Guerrero  José R. 《Natural Hazards》2020,102(3):1225-1248

Natural Hazards - We have evaluated slope stability conditions considering different triggering conditions for the Olinalá landslide, a paleo-landslide located in the northern front of the...  相似文献   

Interface creep behavior of grouted anchors in clayey soils: effect of soil moisture condition     

Zhang  Genbao  Chen  Changfu  Zornberg  Jorge G.  Morsy  Amr M.  Mao  Fengshan 《Acta Geotechnica》2020,15(8):2159-2177

This study aims at investigating the influence of moisture conditions on interface shear behavior of element-grouted anchor specimens embedded in clayey soils. The tests involved comparatively short embedment lengths and a device that was specially designed to facilitate moisture conditioning. Rapidly loaded pullout tests as well as pullout tests under sustained (creep) loading were conducted to characterize both the short-term and long-term ultimate shear strength of anchor–soil interfaces. Both values of the interface shear strength were found to decrease exponentially with increasing moisture content values, although their ratio was found to show a linearly decreasing trend with increasing moisture content. The interface shear creep response under pullout conditions was characterized by a rheological hybrid model that could be calibrated using experimental measurements obtained under increasing stress levels. The accuracy of the hybrid model was examined by evaluating the stress-dependent prediction model as well as its governing parameters. This investigation uncovers the coupled impact of soil moisture condition and external stress state on the time-dependent performance of grouted anchors embedded in clayey soils by correlating the interface shear strength with soil moisture content and associating the creep model with stress levels applied to the grout–soil interface.

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Active and passive arching stresses outside a deep trapdoor     

Costa  Yuri D. J.  Zornberg  Jorge G. 《Acta Geotechnica》2020,15(11):3211-3227

Acta Geotechnica - The classic trapdoor configuration has been useful to examine the changes in stresses expected on buried structures. However, the primary focus of previous studies has been on...  相似文献   

Assessment of Holothuria arguinensis feeding rate,growth and absorption efficiency under aquaculture conditions     

Jorge A. Domínguez-Godino  Mercedes González-Wangüemert 《新西兰海洋与淡水研究杂志》2019,53(1):60-76

Holothuria arguinensis is a potential species for sea cucumber aquaculture in Europe. In a first experiment, feeding rate (FR), growth, absorption efficiency (AE) and survival of adults (135.01?±?10.87?g eviscerated weight) were assessed under sediment tank conditions. In a second experiment, the feasibility to use sea bream (Sparus aurata) biodeposits as a food source was studied for adults (168.69?±?14.59?g eviscerated weight). Individuals in the first experiment showed an increase of weight (specific growth rate (SGR)?=?0.2% d^?1), positive FRs and mean value of AE close to 80% with a mean organic matter content of 90.07?±?11.5?mg/g in the offered sediment. Sea cucumbers fed with fish biodeposits showed a reduction of weight (SGR??1), low FRs and negative values of AE. The influence of low salinity and temperature during experiments should be considered to explain these results. Indeed, sea cucumbers can be affected by a decrease of these parameters during winter months resulting in a period of inactivity.  相似文献   

Geochemistry of Famennian to Visean Metapelites from the Iberian Pyrite Belt: Implications for Provenance,Paleo-Redox Conditions and Vectoring to Massive Sulfide Deposits     

Luz  Filipa  Mateus  António  Rosa  Carlos  Figueiras  Jorge 《Natural Resources Research》2020,29(6):3613-3652

Natural Resources Research - Massive sulfide deposits of the Iberian Pyrite Belt (IPB) document the progression of ore-forming processes in the SW Iberian Variscides, throughout uppermost Devonian...  相似文献   

Pockforms: an evaluation of pockmark-like seabed features on the Landes Plateau, Bay of Biscay   总被引：1，自引：1，他引：0  

Jorge Iglesias  Gemma Ercilla  Soledad García-Gil  Alan G. Judd 《Geo-Marine Letters》2010,30(3-4):207-219

Pockmark-like seabed features located on the Landes Plateau, Bay of Biscay, are depressions up to 1 km across and 50 m deep according to multibeam echo sounder data. Seismic (airgun and TOPAS) profiles show that each feature comprises a stack of identical features which extend down to 300 ms (twt). Three types of depressions, elongate, irregular and circular, appear as non-truncating V-shaped features in the Plio-Quaternary sediments. These features are located above the Parentis Basin where deep faults, basement ridges and diapiric bodies extend upwards across the sedimentary cover, providing ideal migration pathways for any buoyant fluids. Initial inspection suggests that these are classic pockmarks; however, the absence of reflection truncation and the absence of indications of shallow gas beneath the features indicate that they were not formed by the removal of sediment. These are “pockforms” but not “pockmarks”. This paper presents an explanation for the formation of these features, involving collapse and subsidence, sedimentary erosion, and only in some cases the erosion of seabed sediments by probable escaping fluids. These origins are mainly conducted through tectonic fluid dynamics which acted in the area up to the Late Miocene. It might be expected that these features would have been infilled by subsequent sedimentation, but their shape has been preserved because sedimentation in the area mainly comprised muds deposited from low-energy transportation (diluted gravity flows) and settling from hemipelagic suspension.  相似文献   

Late pleistocene/early holocene environments and climates,fauna, and human occupation in the argentine altiplano     

Jorge Fernndez  Vera Markgraf  Hctor O. Panarello  Miguel Albero  Fernando E. Angiolini  Susana Valencio  Mirta Arriaga 《Geoarchaeology》1991,6(3):251-272

The Barro Negro site (23°S lat., 65°37′W long.) in the Altiplano (Puna) of northwestern Argentina contains a well stratified sequence of remains of Hippidion, the American extinct horse, camelids, and archaeological materials, which is the focus of this study. In addition to establishing a reliable chronology, paleoenvironmental information was obtained based on analyses of pollen and stable isotopes (oxygen and carbon) from bone and marl. The data indicate that Hippidion was present at the site between 12,000 and 10,000 yr B. P., at a time when Altoandean grasslands had expanded to lower elevations. By 10,000 yr B.P., when modern semi-arid sub-puna scrub had replaced the Altoandean grasslands, only camelids (Lama or Vicugna) were present, simultaneous with the first evidence of local human occupation. This suggests that a climatic shift from cool and moist (winter rain regime) to warm and dry (summer rain regime) conditions took place simultaneously with the disappearance of the American horse and the appearance of camelids and man.  相似文献