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561.
Numerical simulation of typhoon surges along the coast of Taiwan 总被引:1,自引:1,他引:0
A numerical model has been designed to study the storm surge induced by typhoon along the coast of Taiwan. The governing equations
have been expressed in spherical coordinate system, and a finite difference method has been used to solve them. In the system
of hydrodynamical equations, the nonlinear advection and lateral eddy viscosity terms are prominent in shallow coastal waters.
Air pressure gradient and wind stresses are the driving forces in the model of typhoon surge. The model has been verified
with storm surges induced by Typhoons Herb in 1996, and by typhoons Kai-Tak and Bilis in 2000. 相似文献
562.
Florian Gallien Aberra Mogessie Ernesto Bjerg Sergio Delpino Brigida Castro de Machuca 《Mineralogy and Petrology》2009,95(1-2):135-157
High-temperature, intermediate-pressure calc-silicate marbles occur in the granulite-facies terrain of the La Huerta Range in the Province of San Juan, NW-Argentina, in three bulk-compositional varieties: Type (1) dolomite-absent scapolite-wollastonite-grandite-clinopyroxene-quartz—calcite marbles; Type (2) diopside-forsterite-spinel-corundum—calcite marbles with dolomite exolution lamellae in calcite; Type (3) serpentinized forsterite-spinel-dolomite marbles. An isobaric cooling path from peak-metamorphic conditions of 860°C to 750°C at 6.5 kbar is inferred from scapolite-wollastonite-grandite reaction textures in Type (1) and is consistent with cooling after an advective heat input from related gabbroic and tonalitic intrusive bodies. Stable carbon and oxygen isotope geochemistry was used to decipher the fluid/rock evolution of the three marble types. An interpreted four-stage temperature-time-fluid flow path comprises: (1) infiltration of pre-peak-metamorphic fluids, depleted in δ18O, that caused a shift of primary sedimentary δ18O ratios to lower values (19.6–20.0); (2) syn-metamorphic fluid liberation from Type (1) marbles with evidence for processes close to batch devolatilization that caused a weak coupled 13C and 18O depletion during prograde metamorphism. A different devolatilization behaviour, close to Rayleigh fractionation, texturally associated with fold settings indicates that granulite-facies fluid flow was focused rather than pervasive; (3) H2O-absent conditions were dominant when coronal grandite formed during incipient high-temperature isobaric cooling at the expense of scapolite and wollastonite in the Type (1) marbles; (4) intense post-peak- hydration of Type (2) and Type (3) marbles is the last recognizable metasomatic event. In combination, the three marble types record fluid infiltration both before and after the metamorphic peak. 相似文献
563.
564.
Review of solutions for 3D hydrodynamic modeling applied to aquaculture in South Pacific atoll lagoons 总被引:1,自引:0,他引:1
Andréfouët S Ouillon S Brinkman R Falter J Douillet P Wolk F Smith R Garen P Martinez E Laurent V Lo C Remoissenet G Scourzic B Gilbert A Deleersnijder E Steinberg C Choukroun S Buestel D 《Marine pollution bulletin》2006,52(10):1138-1155
A workshop organized in French Polynesia in November 2004 allowed reviewing the current methods to model the three-dimensional hydrodynamic circulation in semi-enclosed atoll lagoons for aquaculture applications. Mollusk (e.g. pearl oyster, clam) aquaculture is a major source of income for South Pacific countries such as French Polynesia or Cook Islands. This aquaculture now requires a better understanding of circulation patterns to improve the spatial use of the lagoons, especially to define the best area to set larvae collectors. The pelagic larval duration of the relevant species (<20 days) and the size of the semi-closed lagoons (few hundreds of km2) drive the specifications of the model in terms of the spatial and temporal scale. It is considered that, in contrast with fish, mollusk larvae movements are limited and that their cycle occurs completely in the lagoon, without an oceanic stage. Atolls where aquaculture is productive are generally well-bounded, or semi-closed, without significant large and deep openings to the ocean. Nevertheless part of the lagoon circulation is driven by oceanic water inputs through the rim, ocean swells, tides and winds. Therefore, boundary conditions of the lagoon system are defined by the spatial structure of a very shallow rim (exposition and number of hoas), the deep ocean swell climate, tides and wind regimes. To obtain a realistic 3D numerical model of lagoon circulation with adequate forcing, it is thus necessary to connect in an interdisciplinary way a variety of methods (models, remote sensing and in situ data collection) to accurately represent the different components of the lagoon system and its specific boundary conditions. We review here the current methods and tools used to address these different components for a hypothetical atoll of the Tuamotu Archipelago (French Polynesia), representative of the semi-closed lagoons of the South Pacific Ocean. We hope this paper will serve as a guide for similar studies elsewhere and we provide guidelines in terms of costs for all the different stages involved. 相似文献
565.
The great human-environmental diversity of Mexico provides a framework for an initial understanding of the wide disparities between rich and poor. Mexico is still dominated in many regions by agriculture, and during the last 25 years, weather-related disasters have accounted for about 80% of economic losses. This is dramatic, especially considering that this sector produces only ca. 4% of GDP while providing a livelihood to one-quarter of the country’s population. Based on a spatial model, this paper tests the contribution of natural disasters to catalyzing the emigration process in vulnerable regions throughout Mexico. Besides coping and adaptive capacity, we assess the effect of economic losses from disasters in combination with adverse production and trade conditions during the 1990s in triggering out-migration. 相似文献
566.
Fluid‐induced breakdown of monazite in medium‐grade metasedimentary rocks of the Pontremoli basement (Northern Apennines,Italy)
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D. Lo Pò R. Braga H.‐J. Massonne G. Molli A. Montanini T. Theye 《Journal of Metamorphic Geology》2016,34(1):63-84
The last (decompression) stages of the metamorphic evolution can modify monazite microstructure and composition, making it difficult to link monazite dates with pressure and temperature conditions. Monazite and its breakdown products under fluid‐present conditions were studied in micaschist recovered from the cuttings of the Pontremoli1 well, Tuscany. Coronitic microstructures around monazite consist of concentric zones of apatite + Th‐silicate, allanite and epidote. The chemistry and microstructure of the monazite grains, which preserve a wide range of chemical dates ranging from Upper Carboniferous to Tertiary times, suggest that this mineral underwent a fluid‐mediated coupled dissolution–reprecipitation and crystallization processes. Consideration of the chemical zoning (major and selected trace elements) in garnet, its inclusion mineralogy (including xenotime), monazite breakdown products and phase diagram modelling allow the reaction history among accessory minerals to be linked with the reconstructed P–T evolution. The partial dissolution and replacement by rare earth element‐accessory minerals (apatite–allanite–epidote) occurred during a fluid‐present decompression at 510 ± 35 °C. These conditions represent the last stage of a metamorphic history consisting of a thermal metamorphic peak at 575 °C and 7 kbar, followed by the peak pressure stage occurring at 520 °C and 8 kbar. An anticlockwise P–T path or two clockwise P–T loops can fit the above P–T constraints. The former path may be related to a context of late Variscan strike‐slip‐dominated exhumation with minor Tertiary (Alpine‐related) reworking and fluid infiltration, while the latter requires an Oligocene–Miocene fluid‐present tectono‐metamorphic overprint on the Variscan paragenesis. 相似文献
567.
568.
569.
Seoane S Garmendia M Revilla M Borja A Franco J Orive E Valencia V 《Marine pollution bulletin》2011,62(7):1484-1497
Inverted microscopy is widespread employed for the analysis of phytoplankton composition within water quality monitoring networks. However, the analysis at the lowest taxonomical level is not always required for ecological status assessment. In addition, inverted microscopy can underestimate the small phytoplankton, and not always distinguish photoautotrophic from heterotrophic cells. In this study, as alternative tools, epifluorescence microscopy and High Performance Liquid Chromatography (HPLC) were employed to characterize phytoplankton communities within waters of different trophic condition. Epifluorescence microscopy confirmed its effectiveness to count the small phytoplankton. Furthermore, significant correlations between nutrients of anthropogenic origin and nanoplankton abundances were found. However, this technique resulted very time-consuming. HPLC together with the CHEMTAX program was more appropriate than inverted microscopy, in terms of cost-effectiveness. Also, the main variability patterns observed in the phytoplankton community structure by HPLC coincided with previous findings in the study area. Nevertheless, a rapid screening at the inverted microscope is recommended. 相似文献
570.
Field Survey of the 27 February 2010 Chile Tsunami 总被引:1,自引:0,他引:1
Hermann M. Fritz Catherine M. Petroff Patricio A. Catal��n Rodrigo Cienfuegos Patricio Winckler Nikos Kalligeris Robert Weiss Sergio E. Barrientos Gianina Meneses Carolina Valderas-Bermejo Carl Ebeling Athanassios Papadopoulos Manuel Contreras Rafael Almar Juan Carlos Dominguez Costas E. Synolakis 《Pure and Applied Geophysics》2011,168(11):1989-2010
On 27 February 2010, a magnitude M w?=?8.8 earthquake occurred off the coast of Chile??s Maule region causing substantial damage and loss of life. Ancestral tsunami knowledge from the 1960 event combined with education and evacuation exercises prompted most coastal residents to spontaneously evacuate after the earthquake. Many of the tsunami victims were tourists in coastal campgrounds. The international tsunami survey team (ITST) was deployed within days of the event and surveyed 800?km of coastline from Quintero to Mehuín and the Pacific Islands of Santa María, Mocha, Juan Fernández Archipelago, and Rapa Nui (Easter). The collected survey data include more than 400 tsunami flow depth, runup and coastal uplift measurements. The tsunami peaked with a localized runup of 29?m on a coastal bluff at Constitución. The observed runup distributions exhibit significant variations on local and regional scales. Observations from the 2010 and 1960 Chile tsunamis are compared. 相似文献