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971.
This paper aims to quantify the uncertainty in the application of the Parabolic Bay Shape Equation (PBSE) for a bay in static equilibrium. By means of expert elicitation, a database was generated consisting of the position of the control points that determine the Static Equilibrium Planform (SEP). The elicitation consisted of two parts. In Part 1, 22 expert volunteers were asked to place the three control points that determine the SEP on a vertical aerial photograph of Taquaras–Taquarinhas Bay, a morphologically stable bay in the south of Brazil, approximately 1800 m in width and with an indentation of 750 m. The distribution of the location of the SEP along four evenly spaced (200 m) profiles in the southern part of the bay was determined. The overall bias of the location of the SEP calculated over the four profiles was in the order of 41 m (landward) and the average standard deviation was 116 m. These parameters increased when moving alongshore toward the curved section of the bay. This means that the uncertainty in the application of the PBSE is dependent on the particular point of interest along the bay. In Part 2 of the elicitation, 30 volunteers participated. This time the consequence of the placement of the control points (the corresponding SEP) was visible. Comparing the results from Parts 1 and 2, it was observed that when volunteers were directly confronted with the result of the placement of the control points (a plotted SEP) a much smaller variation in the position of the SEP occurred. This implies that when feedback on the result is provided the PBSE is a more robust method. 相似文献
972.
Mario González-Escobar Francisco Suárez-Vidal José Antonio Hernández-Pérez Arturo Martín-Barajas 《Geo-Marine Letters》2010,30(6):575-584
This study examines the structural characteristics of the northern Gulf of California by processing and interpreting ca. 415 km of two-dimensional multi-channel seismic reflection lines (data property of Petróleos Mexicanos PEMEX) collected in the vicinity of the border between the Wagner and Consag basins. The two basins appear to be a link between the Delfín Superior Basin to the south, and the Cerro Prieto Basin to the north in the Mexicali-Imperial Valley along the Pacific–North America plate boundary. The seismic data are consistent with existing knowledge of four main structures (master faults) in the region, i.e., the Percebo, Santa María, Consag Sur, and Wagner Sur faults. The Wagner and Consag basins are delimited to the east by the Wagner Sur Fault, and to the west by the Consag Sur Fault. The Percebo Fault borders the western margin of the modern Wagner Basin depocenter, and is oriented N10°W, dipping (on average) ~40° to the northeast. The trace of the Santa María Fault located in the Wagner Basin strikes N19°W, dipping ~40° to the west. The Consag Sur Fault is oriented N14°W, and dips ~42° to the east over a distance of 21 km. To the east of the study area, the Wagner Sur Fault almost parallels the Consag Sur Fault over a distance of ~86 km, and is oriented N10°W with an average dip of 59° to the east. Moreover, the data provide new evidence that the Wagner Fault is discontinuous between the two basins, and that its structure is more complex than previously reported. A structural high separates the northern Consag Basin from the southern Wagner Basin, comprising several secondary faults oriented NE oblique to the main faults of N–S direction. These could represent a zone of accommodation, or transfer zone, where extension could be transferred from the Wagner to the Consag Basin, or vice versa. This area shows no acoustic basement and/or intrusive body, which is consistent with existing gravimetric and magnetic data for the region. 相似文献
973.
Anderson H. Melo Peryclys R. O. Andrade Antonio J. C. Magalhães Daniel G. C. Fragoso Francisco P. Lima-Filho 《Basin Research》2020,32(5):1054-1080
Five 3rd-order depositional sequences are interpreted from the early Albian to late Campanian interval in the Potiguar Basin. An integrated analysis of seismic interpretations, well logs, cores and biostratigraphic data provides a stratigraphic framework composed by stratigraphic surfaces, systems tracts and sequences. Depositional Sequence 1 and 2 are, respectively, Albian and early to mid-Cenomanian aged and are composed by the falling stage, low stand, transgressive and high stand systems tracts. Depositional Sequence 3 is late Cenomanian to mid-Turonian aged and is composed by the transgressive and high stand systems tracts. Depositional sequences 4 and 5 are, respectively, late Turonian to mid-Santonian and late Santonian to mid-Campanian aged and are composed only by transgressive and high stand systems tracts. The lack of falling stage and low stand systems tracts in depositional sequences 3, 4 and 5, as well the increasing in transgressive and highstand systems tracts thickness as depositional sequences get younger, are reflection of an overall transgressive trend of a 2nd-order sequence. The interpretation proposed in this paper correlates onshore with offshore deposits within a seismic scale (3rd-order) sequence stratigraphy framework. This approach allows a better understanding of the Açu Formation, the primary oil-bearing formation of the Potiguar Basin. The Açu Formation is part of depositional sequences 1, 2 and 3 and is characterized by lateral and vertical variations of depositional systems instead of being associated to a specific depositional system. This sequence stratigraphy analysis can be used as a low-resolution framework for future high-resolution (4th-order scale) studies. 相似文献
974.
V. G. Veloso G. Neves M. Lozano A. Perez-Hurtado C. G. Gago F. Hortas & F. Garcia Garcia 《Marine Ecology》2008,29(S1):126-133
Demands for public outdoor recreation and urbanization are a potential source of environmental disturbances, particularly on sandy beaches. These habitats have therefore experienced rapid degradation worldwide. Talitrid amphipods, which are common inhabitants of sandy beaches, are probably good indicators of such disturbances. In this study, we evaluated the responses of the two amphipods Talitrus saltator and Atlantorchestoidea brasiliensis to human pressure on Spanish and a Brazilian beach, hypothesizing that disregarding species differences, their population sizes will decline under urbanized conditions. The Barra da Tijuca (Brazil) and Levante (Spain) beaches have mixed landscapes with varying levels of development, and each has a protected area (MPA) adjacent to urbanized sites. Numbers of talitrids as well as visitors were compared among sites on each beach. Talitrids were most abundant at the protected sites. This was true of both beaches, even though temporal patterns of human activity were quite different, with Levante experiencing sharp declines in the number of visitors during its harsh winter. Urbanized sites did not experience high Talitrid densities even during a period of low human pressure. On this basis, T. saltator and A. brasiliensis were considered good indicators of urbanization and recreational activities on sandy beaches. MPAs were found to be very important for the successful conservation of the talitrid populations. A feasible method of managing human pressure and thereby conserving beach biodiversity therefore seems to be the establishment of beach MPAs. 相似文献
975.
The aim was to evaluate the antioxidant defences and the occurrence of oxidative damage in Posidonia oceanica under a stress situation due to the epiphytism of the invasive macroalgae Lophocladia lallemandii. P. oceanica leaves were collected in the absence (control station) and in the presence of the epiphytic algae L. lallemandii and the antioxidant enzyme activities, markers of oxidative damage, and hydrogen peroxide production were determined. Antioxidant enzyme - catalase, glutathione peroxidase and superoxide dismutase - activities were significantly higher in Posidonia epiphytized by L. lallemandii. Malondialdehyde, protein carbonyl derivates, and glutathione levels were also higher in L. lallemandii epiphytized P. oceanica leaves compared to control samples. The production of hydrogen peroxide was also significantly increased when Posidonia was epiphytized by L. lallemandii. The invasion of P. oceanica meadows by L. lallemandii appeared to induce oxidative stress in the seagrass as evidenced by increased levels of oxidative stress markers and antioxidant defences. 相似文献
976.
Antonio Alfonso-Faus 《Astrophysics and Space Science》2009,321(1):69-72
It is shown that the usual choice of units obtained by taking G=c=ℏ=1, giving the Planck’s units of mass, length and time, introduces an artificial contradiction between cosmology and particle
physics: the lambda problem that we associate with ℏ. We note that the choice of ℏ=1 does not correspond to the scale of quantum physics. For this scale we prove that the correct value is ℏ≈1/10122, while the choice of ℏ=1 corresponds to the cosmological scale. This is due to the scale factor of 1061 that converts the Planck scale to the cosmological scale. By choosing the ratio G/c
3=constant=1, which includes the choice G=c=1, and the momentum conservation mc=constant, we preserve the derivation of the Einstein field equations from the action principle. Then the product Gm/c
2=r
g
, the gravitational radius of m, is constant. For a quantum black hole we prove that ℏ≈r
g
2≈(mc)2. We also prove that the product Λℏ is a general constant of order one, for any scale. The cosmological scale implies Λ≈ℏ≈1, while the Planck scale gives Λ≈1/ℏ≈10122. This explains the Λ problem. We get two scales: the cosmological quantum black hole (QBH), size ∼1028 cm, and the quantum black hole (qbh) that includes the fundamental particles scale, size ∼10−13 cm, as well as the Planck’ scale, size ∼10−33 cm.
相似文献
977.
Simone Gabriele Parisi Moreno Mauro Antoniazzi Gabriele Cola Lorenzo Lovat Luigi Mariani Giacomo Morreale Kiss Zoltan Antonio Calò 《Climatic change》2014,126(3-4):443-454
Since 1740 until now, the Book of Vine Branches encompasses beautiful pictorial representations of shoots and sprouts, collected every year on April 24th in the vineyards of the Hungarian town of K?szeg. A long time series (1740–2009) of sprouts phenological development coded with the BBCH scale is obtained through paintings visual inspection. Consequently, a model relating sprouts development with thermal resources accumulation is developed on the base of Wien daily air temperature series for the 1857–2009 period. Thermal resources is obtained with the Normal Heat Hours approach, a response curve method that takes into account the nonlinear response of phenological development to temperature. The model, calibrated and validated on the 1930–2009 period, shows an overestimation of thermal resources when applied to the 1857–1929, due to the more advanced phenology of that phase. Since this advance can be ascribed to genetics and management instead of more favorable thermal conditions, model outputs previous to 1930 are decreased by a constant factor. Finally, the 1740–2009 time series of grapevine spring thermal resources is obtained applying the model to the complete phenological time series. The analysis of the series highlights a first phase (1740–1780) characterized by high and stable availability of thermal resources during the 1740–1780, a second phase (1781–1820) with the lowest level of resources, a phase of intermediate availability (1821–1929) and a final present phase (1930–2009) with renewed high availability. The adopted method overcomes the lack of correlation for the post 1960 period shown by previous works. 相似文献
978.
Dongxu YANG Yi LIU Hartmut BOESCH Lu YAO Antonio DI NOIA Zhaonan CAI Naimeng LU Daren LYU Maohua WANG Jing WANG Zengshan YIN Yuquan ZHENG 《大气科学进展》2021,38(1):8-11
The 1st Chinese carbon dioxide(CO2)monitoring satellite mission,TanSat,was launched in 2016.The 1st TanSat global map of CO2 dry-air mixing ratio(XCO2)measurements over land was released as version 1 data product with an accuracy of 2.11 ppmv(parts per million by volume).In this paper,we introduce a new(version 2)TanSat global XCO2 product that is approached by the Institute of Atmospheric Physics Carbon dioxide retrieval Algorithm for Satellite remote sensing(IAPCAS),and the European Space Agency(ESA)Climate Change Initiative plus(CCI+)TanSat XCO2 product by University of Leicester Full Physics(UoL-FP)retrieval algorithm.The correction of the measurement spectrum improves the accuracy(?0.08 ppmv)and precision(1.47 ppmv)of the new retrieval,which provides opportunity for further application in global carbon flux studies in the future.Inter-comparison between the two retrievals indicates a good agreement,with a standard deviation of 1.28 ppmv and a bias of?0.35 ppmv. 相似文献
979.
Luís?González?MenéndezEmail author Antonio?Azor Alvaro?Rubio?Ordó?ez Isabel?Sánchez-Almazo 《International Journal of Earth Sciences》2011,100(7):1533-1550
The Nisa-Alburquerque granitic batholith (southern Variscan Belt, Iberian Peninsula) has been studied by petrological, structural
and geophysical approaches, obtaining contrasting models for its deep structure and emplacement sequence. In order to test
these models and gain knowledge on the thermal increase induced by the intrusion, we have studied its contact aureole, which
was developed in similar country rock lithologies (mica schists alternating with metasandstones and feldespatic schists) all
along the northern external contact of the batholith. Our results indicate no change in metamorphic grade and some variations
in aureole width, which narrows toward the western sectors of the batholith. Cordierite is the only contact metamorphic mineral
developed together with a high temperature biotite probably related to the granite thermal input. By considering these new
data, together with zircon saturation temperatures within the granite and previous petrological and geophysical studies, we
propose a model in which the feeder zones of the granitic magmas were an eastern main one and a western secondary one. We
have also made comparisons of the metamorphic grade in the country rocks and the xenoliths within the granite. Most of the
xenoliths have the same metamorphic facies as the country rocks (Crd-zone), though some of them contain slightly different
assemblages (And + Crd), which could be explained in different ways: (1) differences in the primary schist compositions, (2)
increased time-span of xenoliths in contact with the melt and (3) xenolith incorporation at slightly higher depths during
final granite ascent. 相似文献
980.
R. Nagarajan Priyadarsi D. Roy M.P. Jonathan Rufino Lozano Franz L. Kessler M.V. Prasanna 《Chemie der Erde / Geochemistry》2014
Multi-element geochemistry and mineralogy are used to characterize the chemical composition, degree of paleo-weathering, provenance and tectonic settings of the Neogene sedimentary rocks of Borneo Basin of east Malaysia. Sedimentary rocks are classified as extremely weathered sandstones (i.e. wacke, arkose, litharenite, Fe-sandstone and quartz arenite). Wacke, arkose, litharenite and Fe-sandstone are characterized by post-depositional K-metasomatism and zircon enrichment through sediment recycling. Geochemical characteristics suggest a mixed-nature provenance for the sandstones and the variable tectonic settings possibly mirror the complexity of the basin. Enriched Cr in quartz arenite and Fe-sandstone are related to the contribution from ophiolite or fractionation of Cr-bearing minerals. 相似文献