The 2006 Bahía Asunción Earthquake Swarm: Seismic Evidence of Active Deformation Along the Western Margin of Baja California Sur,Mexico     

Luis Munguía  Sergio Mayer  Alfredo Aguirre  Ignacio Méndez  Mario González-Escobar  Manuel Luna 《Pure and Applied Geophysics》2016,173(10-11):3615-3629

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Eastern boundary drainage of the North Atlantic subtropical gyre     

Irene Laiz  Jose Luis Pelegrí  Francisco Machín  Pablo Sangrà  Alonso Hernández-Guerra  Angeles Marrero-Díaz  Angel Rodríguez-Santana 《Ocean Dynamics》2012,62(9):1287-1310

The eastern boundary of the North Atlantic subtropical gyre (NASG) is an upwelling favorable region characterized by a mean southward flow. The Canary Upwelling Current (CUC) feeds from the interior ocean and flows south along the continental slope off NW Africa, effectively providing the eastern boundary condition for the NASG. We follow a joint approach using slope and deep-ocean data together with process-oriented modeling to investigate the characteristics and seasonal variability of the interior–coastal ocean connection, focusing on how much NASG interior water drains along the continental slope. First, the compiled sets of data show that interior central waters flow permanently between Madeira and the Iberian Peninsula at a rate of 2.5?±?0.6 Sv (1 Sv = 10⁶ m³ s^-1 10⁹ km s^-1), with most of it reaching the slope and shelf regions north of the Canary Islands (1.5?±?0.7?Sv). Most of the water entering the African slope and shelf regions escapes south between the easternmost Canary Islands and the African coast: In 18 out of 22 monthly realizations, the flow was southward (?0.9?±?0.4?Sv) although an intense flow reversal occurred usually around November (1.7?±?0.9?Sv), probably as the result of a late fall intensification of the CUC north of the Canary Islands followed by instability and offshore flow diversion. Secondly, we explore how the eastern boundary drainage may be specified in a process-oriented one-layer quasigeostrophic numerical model. Non-zero normal flow and constant potential vorticity are alternative eastern boundary conditions, consistent with the idea of anticyclonic vorticity induced at the boundary by coastal jets. These boundary conditions cause interior water to exit the domain at the boundary, as if recirculating through the coastal ocean, and induce substantial modifications to the shape of the eastern NASG. The best model estimate for the annual mean eastward flow north of Madeira is 3.9?Sv and at the boundary is 3.3?Sv. The water exiting at the boundary splits with 1?Sv flowing into the Strait of Gibraltar and the remaining 2.3?Sv continuing south along the coastal ocean until the latitude of Cape Ghir. The model also displays significant wind-induced seasonal variability, with a maximum connection between the interior and coastal oceans taking place in autumn and winter, in qualitative agreement with the observations.  相似文献   

ADM1‐Based Robust Interval Observer for Anaerobic Digestion Processes     

José Luis Montiel‐Escobar  Víctor Alcaraz‐González  Hugo Oscar Méndez‐Acosta  Victor González‐Álvarez 《洁净——土壤、空气、水》2012,40(9):933-940

A robust state estimation scheme is proposed for anaerobic digestion (AD) processes to estimate key variables under the most uncertain scenarios (namely, uncertainties on the process inputs and unknown reaction and specific growth rates). This scheme combines the use of the IWA Anaerobic Digestion Model No. 1 (ADM1), the interval observer theory and a minimum number of measurements to reconstruct the unmeasured process variables within guaranteed lower and upper bounds in which they evolve. The performance of this robust estimation scheme is evaluated via numerical simulations that are carried out under actual operating conditions. It is shown that under some structural and operational conditions, the proposed robust interval observer (RIO) has the property of remaining stable in the face of uncertain process inputs, badly known kinetics and load disturbances. It is also shown that the RIO is indeed a powerful tool for the estimation of biomass (composed of seven different species) from a minimum number of measurements in a system with a total of 32 variables from which 24 correspond to state variables.  相似文献   

The Spanish approach to marine spatial planning. Marine Strategy Framework Directive vs. EU Integrated Maritime Policy   总被引：1，自引：0，他引：1  

Juan Luis Suárez de Vivero  Juan Carlos Rodríguez Mateos 《Marine Policy》2012,36(1):18-27

The coming into effect of the Directive 2008/56/EC (Marine Strategy Framework Directive (MSFD)) will induce European Union member States to create mechanisms for managing maritime space in order to comply with the goals set out in this binding legislation. This leads one to think that marine spatial planning in various countries in the EU will be directed at complying with the Directive's environmental goals, as is the case in Spain, rather than undertaking proactive planning for developing the maritime sectors. To put the case of Spain into perspective, a review is conducted of the initiatives taken, especially in Europe and the European Union, exploring the correlations between the main focuses of the maritime sectors and the planning systems. The analysis of the Spanish initiative demonstrates how the maritime economy model and geopolitical factors explain the planning options for the marine environment. In other respects, with the coming into effect of the MSFD, a dual institutional course for marine spatial planning seems to be opening up in the EU: Integrated Maritime Policy vs. the Marine Strategy Framework Directive.  相似文献   

Copper speciation in continental inputs to the Vigo Ria: sewage discharges versus river fluxes   总被引：1，自引：0，他引：1  

Santos-Echeandia J  Laglera LM  Prego R  van den Berg CM 《Marine pollution bulletin》2008,56(2):308-317

Continental inputs of copper via rivers and sewage into the Vigo Ria were evaluated. The main fluvial input is not contaminated and the most degraded discharges occur on the southern margin of the middle ria. Continental inputs of copper and ligands to the ria are dominated by sewage treatment plants (136 mol Cu day(-1), 124 mol L day(-1)) supported by rivers (15 mol Cu day(-1), 21 mol L day(-1)). The dissolved fraction is the main channel of discharge for rivers (66%) with particulate matter being predominant in sewage (63%). Dissolved copper is organically complexed both in rivers (99.8%) and sewage (99.9%). This minor difference may be attributed to the fact that the stability of sewage complexes is greater than those in rivers. Moreover, ligand concentrations are higher in sewage than in rivers. Thus, the natural continental inputs of copper and ligands into the ria are magnified by anthropogenic inputs (5-15 and 3-5 times higher for copper and ligands, respectively).  相似文献   

Seismic damage evaluation in urban areas using the capacity spectrum method: Application to Barcelona   总被引：8，自引：0，他引：8  

Alex H. Barbat  Luis G. Pujades  Nieves Lantada 《Soil Dynamics and Earthquake Engineering》2008,28(10-11):851

Conceptual aspects related to seismic vulnerability, damage and risk evaluation are discussed first, together with a short review of the most widely used possibilities for seismic evaluation of structures. The capacity spectrum method and the way of obtaining seismic damage scenarios for urban areas starting from capacity and fragility curves are then discussed. The determination of capacity curves for buildings using non-linear structural analysis tools is then explained, together with a simplified expeditious procedure allowing the development of fragility curves. The seismic risk of the buildings of Barcelona, Spain, is analyzed in the paper, based on the application of the capacity spectrum method. The seismic hazard in the area of the city is described by means of the reduced 5% damped elastic response spectrum. The information on the buildings was obtained by collecting, arranging, improving and completing a broad database of the dwellings and current buildings. The buildings existing in Barcelona are mainly of two types: unreinforced masonry structures and reinforced concrete buildings with waffled-slab floors. The ArcView software was used to create a GIS tool for managing the collected information in order to develop seismic risk scenarios. This study shows that the vulnerability of the buildings is significant in Barcelona and, therefore, in spite of the low-to-moderate seismic hazard in the region, the expected seismic risk is considerable.  相似文献   

海洋中尺度涡与内波的地震图像   总被引：10，自引：5，他引：5       下载免费PDF全文

宋海斌  Luis Pinheiro  王东晓  董崇志  宋洋  拜阳 《地球物理学报》2009,52(11):2775-2780

海洋反射地震通常用于调查、研究海底地质构造,勘探油气与天然气水合物资源.近期研究表明多道反射地震方法也可以对水柱的热盐细结构成像.中尺度涡与内波是重要的物理海洋现象,但是常规的物理海洋调查是在间隔若干公里的离散测站上进行的,水平分辨率较低,因此对中尺度涡的结构与内波的横向分布了解较差.本文利用在大西洋东部、南海采集的地震数据给出了低频反射地震可以对中尺度涡与内波清晰成像的新的证据.反射地震方法较传统海洋观测手段,具有明显的优势,主要体现在高的水平分辨率和短时间内对整个海水剖面进行成像方面．从地震剖面上,能够清楚地观测到中尺度涡、内波造成的反射特征变化,从而有助于改进对能量在不同尺度的海水运动之间传递过程的认识.  相似文献   

Geoeffectiveness of solar flares in magnetic crochet (sfe) production: I—Dependence on their spectral nature and position on the solar disk     

Juan José Curto  Luis R. Gaya-Piqué 《Journal of Atmospheric and Solar》2009,71(17-18):1695-1704

The influence of the spectral nature and position on the solar disk of solar flares related to the production of magnetic effects on earth (from now on, sfe) over a more than 30-year period has been studied. Regarding the spectral issue, we found that the probability of a flare to produce sfe depends on the spectral band in which we observe it, being higher when the flare is important both in Hα and X-ray emissions. On the other hand, Hα and X-ray emissions have been considered in many different divisions of the solar surface and their effectiveness on sfe production have been compared. We found that there is not any privileged region on the solar disk for sfe production. These results end with the controversy generated by distinct conclusions obtained in classical studies on the subject.  相似文献   

Geoeffectiveness of solar flares in magnetic crochet (sfe) production: II—Dependence on the detection method     

Juan José Curto  Luis R. Gaya-Piqué 《Journal of Atmospheric and Solar》2009,71(17-18):1705-1710

During magnetic active periods, disturbances in the geomagnetic field can act as natural noise masking other magnetic variations of small amplitude. In this paper, the influence of these perturbations on the observation of the effects on Earth of solar flares (sfe) has been studied. The diurnal and monthly values of detected sfe have been obtained, as well as the temporal variation of the relative occurrence of events. These numbers show how the irregular distribution of the magnetic observatories is an important limitation in the efficiency of the detection method. Some considerations about the actual method used at the International Service on Rapid Magnetic Variations are finally presented.  相似文献   

Phytoplankton community variations in tropical coastal area affected where submarine groundwater occurs     

Luis Troccoli-Ghinaglia  Jorge A. Herrera-Silveira  Francisco A. Comín  José Rafael Díaz-Ramos 《Continental Shelf Research》2010

The influence of subterranean water discharge on phytoplankton was studied at two localities (Progreso and Dzilam) on the northern coast of the Yucatan Peninsula. Hydrographic and phytoplankton samples were taken monthly between September 1998 and August 1999. High concentration of silicate (>65 μmol L⁻¹) and nitrate (>80 μmol L⁻¹) and low salinity showed the influence of submerged groundwater discharge (SGD) in the area. In Dzilam, hydrological conditions shows low salinity and high concentration of nitrate and silicate favored from the SGD. Meanwhile, high concentrations of ammonium, nitrite, and phosphate at Progreso (>150 000 inhabitants) suggest mixing of SGD and domestic waste waters. Thick-valve pennate diatoms dominated at Dzilam while dinoflagellates dominated in Progreso. Hydrological differences in both study zones suggest that local forcings, and interaction between coastal water masses and SGD plays an important role in hydrological conditions and primary productivity in the coastal zone of Yucatan. The anthropogenic modified SGD in Progreso may affect the nutrient regime and phytoplankton community structure, and may be used as indicator of eutrophication.  相似文献