Secular dynamics of multiplanetary circumbinary systems: stationary solutions and binary-planet secular resonance     

Eduardo Andrade-Ines  Philippe Robutel 《Celestial Mechanics and Dynamical Astronomy》2018,130(1):6

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Area usage estimation and spatiotemporal variability in distribution patterns of southern right whales,Eubalaena australis,of southern Brazil          下载免费PDF全文

Eduardo Pires Renault‐Braga  Karina Rejane Groch  Paulo A. de Carvalho Flores  Eduardo R. Secchi  Luciano Dalla‐Rosa 《Marine Ecology》2018,39(3)

Southern right whales—Eubalaena australis (Desmoulins, 1822)—migrate seasonally from high‐latitude feeding grounds to coastal breeding and calving grounds at lower latitudes such as the southern coast of Brazil. Understanding how these whales are distributed along the coast is important for monitoring their postwhaling recovery and defining management strategies. In this study, we applied Kernel density estimators to aerial survey data to determine main occurrence and concentration areas of right whales in southern Brazil and investigate inter‐ and intra‐annual distribution patterns between 2003 and 2012. Our results show considerable variation in area usage within and among years, and changes in the general distribution pattern of right whales in the last years of the study. Intra‐annually, higher concentration area tended to expand from July to September and decrease in November. Some areas stood out as high‐density areas for right whales: Ribanceira/Ibiraquera, Itapirubá Sul/Sol, and from Arroio to Gaivota. Some evidences also suggest preferential areas for mother–calf pairs. The higher concentration area of right whales in southern Brazil was estimated at 52,541 km² and the occurrence area was 682.69 km², which is the whole study area. As right whale distribution in the region is likely expanding due to this population's current recovery, our study provides essential information for management plan of the Right Whale Environmental Protection Area.  相似文献   

IUGS and the State of the Geosciences——Based on a speech delivered at the Opening Ceremony of the 32nd International Geological Congress in Florence, August 2004     

Eduardo F.J. de Mulder 《《幕》》2005,28(3):224-225

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Fundamental parameters of the LMC clusters NGC 1836, NGC 1860, NGC 1865, SL 444, LW 224 and SL 548     

Andrés E. Piatti  Eduardo Bica  Doug Geisler  Juan J. Clariá 《Monthly notices of the Royal Astronomical Society》2003,344(3):965-977

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The Common Origin of the High Inclination TNO's     

Gomes  Rodney 《Earth, Moon, and Planets》2003,92(1-4):29-42

Numerical integrations of the four major planets orbits inside a primordialplanetesimals disk show that a fraction of Neptune primordial scatteredobjects are deposited into the classical Kuiper Belt at Solar System age. Theseobjects exhibit inclinations as high as 40° and can account forpresent high inclinations population in the classical Kuiper Belt. The samemechanism can also originate high perihelion scattered objects like 2000 CR₁₀₅. The process that in the end produced such objects can be divided into two phases, a migration phase where nonconservative dynamics acted to producesome stable objects already at 10⁸ years and a nonmigrating phase that helped to establish some other objects as stable TNO's. Low inclination CKBO's have inprinciple an origin through the resonance sweeping process, although someresults from numerical integrations at least suggest a possible origin also fromthe primordial Neptune scattered population.  相似文献   

'Distinguishing eustatic and epeirogenic controls on Lower-Middle Cambrian boundary successions in West Gondwana (Morocco and Iberia)', by Ed Landing, Gerd Geyer and Wolfram Heldmaier, published in Sedimentology (2006), 53(4), 899–918 – discussion     

Eladio Liñán  María Eugenia Dies†  José Antonio Gámez Vintaned  Rodolfo Gozalo‡  Eduardo Mayoral§ 《Sedimentology》2008,55(4):723-724

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Late Carboniferous porphyry copper mineralization at La Voluntad,Neuquén,Argentina: Constraints from Re–Os molybdenite dating     

Mirta Garrido  Fernando Barra  Eduardo Domínguez  Joaquin Ruiz  Victor A. Valencia 《Mineralium Deposita》2008,43(5):591-597

The La Voluntad porphyry Cu–Mo deposit in Neuquén, Argentina, is one of several poorly known porphyry-type deposits of Paleozoic to Early Jurassic age in the central and southern Andes. Mineralization at La Voluntad is related to a tonalite porphyry from the Chachil Plutonic Complex that intruded metasedimentary units of the Piedra Santa Complex. Five new Re–Os molybdenite ages from four samples representing three different vein types (i.e., quartz–molybdenite, quartz–sericite–molybdenite and quartz–sericite–molybdenite ± chalcopyrite–pyrite) are identical within error and were formed between ~312 to ~316 Ma. Rhenium and Os concentrations range between 34 to 183 ppm and 112 to 599 ppb, respectively. The new Re–Os ages indicate that the main mineralization event at La Voluntad, associated to sericitic alteration, was emplaced during a time span of 1.7 ± 3.2 Ma and that the deposit is Carboniferous in age, not Permian as previously thought. La Voluntad is the oldest porphyry copper deposit so far recognized in the Andes and indicates the presence of an active magmatic arc, with associated porphyry style mineralization, at the proto-Pacific margin of Gondwana during the Early Pennsylvanian.  相似文献   

Origins of high pH mineral waters from ultramafic rocks, Central Portugal     

Jos M. Marques  Paula M. Carreira  Maria Rosrio Carvalho  Maria J. Matias  Fraser E. Goff  Maria J. Basto  Rui C. Graa  Luís Aires-Barros  Luís Rocha 《Applied Geochemistry》2008,23(12):3278-3289

This paper reviews the geochemical, isotopic (²H, ¹⁸O, ¹³C, ³H and ¹⁴C) and numerical modelling approaches to evaluate possible geological sources of the high pH (11.5)/Na–Cl/Ca–OH mineral waters from the Cabeço de Vide region (Central-Portugal). Water–rock interaction studies have greatly contributed to a conceptual hydrogeological circulation model of the Cabeço de Vide mineral waters, which was corroborated by numerical modelling approaches. The local shallow groundwaters belong to the Mg–HCO₃ type, and are derived by interaction with the local serpentinized rocks. At depth, these type waters evolve into the high pH/Na–Cl/Ca–OH mineral waters of Cabeço de Vide spas, issuing from the intrusive contact between mafic/ultramafic rocks and an older carbonate sequence. The Cabeço de Vide mineral waters are supersaturated with respect to serpentine indicating that they may cause serpentinization. Magnesium silicate phases (brucite and serpentine) seem to control Mg concentrations in Cabeço de Vide mineral waters. Similar δ²H and δ¹⁸O suggest a common meteoric origin and that the Mg–HCO₃ type waters have evolved towards Cabeço de Vide mineral waters. The reaction path simulations show that the progressive evolution of the Ca–HCO₃ to Mg–HCO₃ waters can be attributed to the interaction of meteoric waters with serpentinites. The sequential dissolution at CO₂ (g) closed system conditions leads to the precipitation of calcite, magnesite, amorphous silica, chrysotile and brucite, indicating that the waters would be responsible for the serpentinization of fresh ultramafic rocks (dunites) present at depth. The apparent age of Cabeço de Vide mineral waters was determined as 2790 ± 40 a BP, on the basis of ¹⁴C and ¹³C values, which is in agreement with the ³H concentrations being below the detection limit.  相似文献   

Environmental hydrogeology of the southern sector of the Samborombon Bay wetland,Argentina     

Eleonora Carol  Eduardo Kruse  Jorge Pousa 《Environmental Geology》2008,54(1):95-102

The Samborombon Bay wetland is located on the west margin of the Rio de la Plata estuary, in the Province of Buenos Aires, Argentina. This paper analyses the geological, geomorphologic, soil and vegetation characteristics of the southernmost sector of this wetland and their influence on surface water and groundwater. The study area presents three hydrologic units: coastal dunes, sand sheets and coastal plain. Coastal dunes and sand sheets are recharge zones of high permeability with well-drained, non-saline soils, and a few surface water flows. Changes in the water table are related to rainfall. Groundwater in coastal dunes is Ca–Mg–HCO₃ to Na–HCO₃, and of low salinity (590 mg/l). Groundwater in sand sheets is mainly Na–HCO₃ with a salinity of about 1,020 mg/l. The coastal plain exhibits medium to low permeability sediments, with submerged saline soils poorly drained. Groundwater is Na–Cl with a mean salinity of 16,502 mg/l. A surface hydrological network develops in the coastal plain. Surface water levels near the shoreline are affected by tidal fluctuations; far from the shoreline water accumulates because of poor drainage. Both sectors have Na–Cl water, but the former is more saline. Human intervention and sea level rise may affect the wetland severely.  相似文献   

Monitoring Large-Scale Tests for Nuclear Waste Disposal     

Eduardo E. Alonso  Sarah M. Springman  Charles W. W. Ng 《Geotechnical and Geological Engineering》2008,26(6):817-826

Two large-scale “in situ” demonstration experiments and their instrumentation are described. The first test (FEBEX Experiment) involves the hydration of a compacted bentonite barrier under the combined effect of an inner source of heat and an outer water flow from the confining saturated granite rock. In the second case, the progressive de-saturation of Opalinus clay induced by maintained ventilation of an unlined tunnel is analyzed. The paper shows the performance of different sensors (capacitive cells, psychrometers, TDR’s) and a comparison of fill behaviour with modelling results. The long term performance of some instruments could also be evaluated specially in the case of FEBEX test. Capacitive sensors provide relative humidity data during long transient periods characterised by very large variations of suction within the bentonite.  相似文献