A model of characteristic earthquakes and its implications for regional seismicity     

Ricardo López-Ruiz  Miguel Vázquez-Prada  Javier B. Gómez  Amalio F. Pacheco 《地学学报》2004,16(3):116-120

Regional seismicity (i.e. that averaged over large enough areas over long enough periods of time) has a size–frequency relationship, the Gutenberg–Richter law, which differs from that found for some seismic faults, the Characteristic Earthquake relationship. But all seismicity comes in the end from active faults, so the question arises of how one seismicity pattern could emerge from the other. The recently introduced Minimalist Model of Vázquez‐Prada et al. of characteristic earthquakes provides a simple representation of the seismicity originating from a single fault. Here, we show that a Characteristic Earthquake relationship together with a fractal distribution of fault lengths can accurately describe the total seismicity produced in a region. The resulting earthquake catalogue accounts for the addition of both all the characteristic and all the non‐characteristic events triggered in the faults. The global accumulated size–frequency relationship strongly depends on the fault length fractal exponent and, for fractal exponents close to 2, correctly describes a Gutenberg–Richter distribution with a b exponent compatible with real seismicity.  相似文献   

Estimation of Heat Sources in Planetary Crusts from Isotherm Depth,Surface Heat Flow,and Crustal Thickness     

Ruiz  Javier  Tejero  Rosa 《Earth, Moon, and Planets》2002,91(3):185-193

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Cadomian volcanosedimentary complexes across the Ediacaran–Cambrian transition of the Eastern Pyrenees,southwestern Europe     

Padel  Maxime  Álvaro  J. Javier  Casas  Josep Maria  Clausen  Sébastien  Poujol  Marc  Sánchez-García  Teresa 《International Journal of Earth Sciences》2018,107(5):1579-1601

International Journal of Earth Sciences - The volcanism hosted by the Ediacaran–Terreneuvian Canaveilles Group of the Eastern Pyrenees displays two distinct geochemical affinities: (1)...  相似文献   

SO2 degassing from Turrialba Volcano linked to seismic signatures during the period 2008–2012     

Vladimir Conde  Stefan Bredemeyer  Eliecer Duarte  Javier F. Pacheco  Sebastian Miranda  Bo Galle  Thor H. Hansteen 《International Journal of Earth Sciences》2014,103(7):1983-1998

In 1996, after 150 years of relative calm, Turrialba Volcano was reawakening. A visible plume and serious damage to surrounding vegetation due to acid rain are the most obvious signals. As part of the Network for Observation of Volcanic and Atmospheric Change project, four gas-monitoring stations were initially installed on the west flank of the volcano with the purpose of measuring sulphur dioxide emissions during this period of increased activity using the scanning-differential optical absorption spectroscopy technique. We present here the results of semicontinuous gas flux measurements over a period of 5 years (from 2008 to 2012), providing a novel data set that documents a relatively rapid increase in SO₂ fluxes from around 350 t day^?1 to around 4,000 t day^?1 leading up to an eruptive period, followed by a gradual return to the former baseline values. Gas flux data were also compared with seismic data for selected periods of interest, providing insights into the link between degassing and seismicity. The most important result from this comparison is the identification of an inflexion point in the gas emissions followed by a clearly increasing trend in seismic activity, distinguishable 6 months prior to a phreatic eruptive event that occurred on 5 January 2010. This signal can be interpreted as a possible indicator of future eruptive events. Monitoring of SO₂ thus complements seismic monitoring as a forecasting tool for eruptive events. Such monitoring is critical considering the proximity of Turrialba to the Central Valley, an area inhabited by more than 50 % of Costa Rica’s population.  相似文献   

Assessment of groundwater circulation in La Gomera aquifers (Canary Islands, Spain) from their hydrochemical features     

María Leal  Javier Lillo  Álvaro Márquez 《Environmental Earth Sciences》2014,71(1):23-30

La Gomera (Canary Islands, Spain) does not show water scarcity like other islands of the Archipelago. However, the study of its aquifers is paramount as nearly 60 % of the water supplies are covered with spring water. According to the currently accepted hydrogeological model, La Gomera presents an upper aquifer consisting of perched groundwater bodies. Below this hydrogeological unit, the General Saturated Zone or basal groundwater is placed. The model also establishes the presence of flows through them. Many perched groundwater bodies are located under Garajonay National Park where most of the springs are found. Therefore, if upper and lower aquifers are truly connected and new wells are built, the new extractions could affect Garajonay ecosystems. With the aim of identifying spring groups and related potential areas of water transfer, hydrochemical and statistical analyses (principal component analysis and cluster analysis) have been applied. This study shows the great compositional variability of groundwaters, precluding the identification of spring groups, hydrochemical patterns and, therefore, the transfer areas with no possibility of assessing the potential impact of a water demand increase on the Garajonay National Park ecosystems from the present data. Only the springs belonging to group II of the cluster analysis could indicate a transfer area. The lack of conclusive results could be due to: (1) great compositional variability of volcanic materials; (2) unequal influence of marine aerosols; (3) irregular distribution of rainfall; (4) different grades of soils development; and (5) the occurrence of partially disconnected water bodies giving as a result a complex hydrogeological system.  相似文献   

Vulnerability,pressures, and protection of karst caves and their speleothems in Ha Long Bay,Vietnam     

Trinh Anh Duc  Javier Garcia Guinea 《Environmental Earth Sciences》2014,71(11):4899-4913

This paper presents the results of morphological and microclimatic surveys and speleothem analyses of ten karst caves located in different isles in Ha Long Bay, a famous tourist attraction in Vietnam. Characteristically, the caves have enormous entrances, roomy interiors, but short length, typical of karst caves in tropical climates. The cave microclimate was found to be significantly dependent on the outside atmosphere and human activities. There was a clear spatial variation in macro features and fabrics of speleothems from entrance (porous, microcrystalline) to rear (solid, macrocrystalline) of the caves. Microstructure analysis with the use of an environmental scanning electron microscope shows a gradual decrease of biological activity and microclimate instability from outside to the innermost parts of the caves are the causes for this spatial variation. Past and present deterioration of caves and speleothems directly due to tourist activities and vandalism has been observed. On the other hand, there are signs of speleothem regrowth in the caves where tourism has been stopped. This study has proved that caves and their speleothems in Ha Long Bay are highly dynamic and understanding of their environment requires immediate methodological attention. Based on the analytical results, it is recommended that regulation of visitor frequency and removal of lamp-flora are necessary for sustainable development of the show caves and their speleothems.  相似文献   

Erratum: Hydrogeological research on intensively exploited deep aquifers in the ‘Loma de Úbeda’ area (Jaén, southern Spain)     

Antonio González-Ramón  Javier Rodríguez-Arévalo  Sergio Martos-Rosillo  Javier Gollonet 《Hydrogeology Journal》2013,21(4):947-948

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A case of man-induced ground subsidence and building settlement related to karstified gypsum (Oviedo,NW Spain)     

Luis?PandoEmail author  Javier?A.?Pulgar  Manuel?Gutiérrez-Claverol 《Environmental Earth Sciences》2013,69(2):507-521

Within the TERENO initiative, four terrestrial observatories, collecting huge amounts of environmental data, are being set up since 2008. To manage, describe, exchange and publish these data, the distributed Spatial Data Infrastructure TEODOOR (http://www.tereno.net) was created. Each institution responsible for an individual observatory sets up its own local data infrastructure, which may communicate with each other to exchange data and metadata internally or to the public by OGC compliant Web services. The TEODOOR data portal serves as a database node to provide scientists and decision makers with reliable and well-accessible data and data products. Various tools like hierarchical search or Web-GIS functions allow a deeper insight into the different observatories, test sites and sensor networks. Sensor data can be queried and selected for measured parameters, stations and/or time periods, and can be visualized and downloaded according to a shared TERENO data policy. Currently, TEODOOR provides free access to data from more than 500 monitoring stations.  相似文献   

Scientific program construction principles and time allocation scheme for the World Space Observatory—Ultraviolet mission     

Oleg Malkov  Mikhail Sachkov  Boris Shustov  Pavel Kaigorodov  Francisco Javier Yáñez  Ana Ines Gómez de Castro 《Astrophysics and Space Science》2011,335(1):323-327

We present scientific program construction principles and a time allocation scheme developed for the World Space Observatory—Ultraviolet (WSO-UV) mission, which is an international space observatory for observation in UV spectral range 100–300 nm. The WSO-UV consists of a 1.7 m aperture telescope with instrumentation designed to carry out high resolution spectroscopy, long-slit low resolution spectroscopy and direct sky imaging. The WSO-UV Ground Segment is under development by Spain and Russia. They will coordinate the Mission and Science Operations and provide the satellite tracking stations for the project.  相似文献   

Heat Flow and Thermal State of the Crust of the Icy Galilean Satellites     

Javier Ruiz 《Earth, Moon, and Planets》2012,109(1-4):117-125

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